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1 /*
2  * USB hub driver.
3  *
4  * (C) Copyright 1999 Linus Torvalds
5  * (C) Copyright 1999 Johannes Erdfelt
6  * (C) Copyright 1999 Gregory P. Smith
7  * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
8  *
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/completion.h>
16 #include <linux/sched.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
19 #include <linux/ioctl.h>
20 #include <linux/usb.h>
21 #include <linux/usbdevice_fs.h>
22 #include <linux/usb/hcd.h>
23 #include <linux/usb/otg.h>
24 #include <linux/usb/quirks.h>
25 #include <linux/kthread.h>
26 #include <linux/mutex.h>
27 #include <linux/freezer.h>
28 #include <linux/random.h>
29 #include <linux/pm_qos.h>
30 
31 #include <asm/uaccess.h>
32 #include <asm/byteorder.h>
33 
34 #include "hub.h"
35 
36 /* if we are in debug mode, always announce new devices */
37 #ifdef DEBUG
38 #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES
39 #define CONFIG_USB_ANNOUNCE_NEW_DEVICES
40 #endif
41 #endif
42 
43 #define USB_VENDOR_GENESYS_LOGIC		0x05e3
44 #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND	0x01
45 
hub_is_superspeed(struct usb_device * hdev)46 static inline int hub_is_superspeed(struct usb_device *hdev)
47 {
48 	return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS);
49 }
50 
51 /* Protect struct usb_device->state and ->children members
52  * Note: Both are also protected by ->dev.sem, except that ->state can
53  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
54 static DEFINE_SPINLOCK(device_state_lock);
55 
56 /* khubd's worklist and its lock */
57 static DEFINE_SPINLOCK(hub_event_lock);
58 static LIST_HEAD(hub_event_list);	/* List of hubs needing servicing */
59 
60 /* Wakes up khubd */
61 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait);
62 
63 static struct task_struct *khubd_task;
64 
65 /* cycle leds on hubs that aren't blinking for attention */
66 static bool blinkenlights = 0;
67 module_param (blinkenlights, bool, S_IRUGO);
68 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs");
69 
70 /*
71  * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
72  * 10 seconds to send reply for the initial 64-byte descriptor request.
73  */
74 /* define initial 64-byte descriptor request timeout in milliseconds */
75 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
76 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
77 MODULE_PARM_DESC(initial_descriptor_timeout,
78 		"initial 64-byte descriptor request timeout in milliseconds "
79 		"(default 5000 - 5.0 seconds)");
80 
81 /*
82  * As of 2.6.10 we introduce a new USB device initialization scheme which
83  * closely resembles the way Windows works.  Hopefully it will be compatible
84  * with a wider range of devices than the old scheme.  However some previously
85  * working devices may start giving rise to "device not accepting address"
86  * errors; if that happens the user can try the old scheme by adjusting the
87  * following module parameters.
88  *
89  * For maximum flexibility there are two boolean parameters to control the
90  * hub driver's behavior.  On the first initialization attempt, if the
91  * "old_scheme_first" parameter is set then the old scheme will be used,
92  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
93  * is set, then the driver will make another attempt, using the other scheme.
94  */
95 static bool old_scheme_first = 0;
96 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
97 MODULE_PARM_DESC(old_scheme_first,
98 		 "start with the old device initialization scheme");
99 
100 static bool use_both_schemes = 1;
101 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
102 MODULE_PARM_DESC(use_both_schemes,
103 		"try the other device initialization scheme if the "
104 		"first one fails");
105 
106 /* Mutual exclusion for EHCI CF initialization.  This interferes with
107  * port reset on some companion controllers.
108  */
109 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
110 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
111 
112 #define HUB_DEBOUNCE_TIMEOUT	2000
113 #define HUB_DEBOUNCE_STEP	  25
114 #define HUB_DEBOUNCE_STABLE	 100
115 
116 static void hub_release(struct kref *kref);
117 static int usb_reset_and_verify_device(struct usb_device *udev);
118 
portspeed(struct usb_hub * hub,int portstatus)119 static inline char *portspeed(struct usb_hub *hub, int portstatus)
120 {
121 	if (hub_is_superspeed(hub->hdev))
122 		return "5.0 Gb/s";
123 	if (portstatus & USB_PORT_STAT_HIGH_SPEED)
124     		return "480 Mb/s";
125 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
126 		return "1.5 Mb/s";
127 	else
128 		return "12 Mb/s";
129 }
130 
131 /* Note that hdev or one of its children must be locked! */
usb_hub_to_struct_hub(struct usb_device * hdev)132 struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
133 {
134 	if (!hdev || !hdev->actconfig || !hdev->maxchild)
135 		return NULL;
136 	return usb_get_intfdata(hdev->actconfig->interface[0]);
137 }
138 
usb_device_supports_lpm(struct usb_device * udev)139 static int usb_device_supports_lpm(struct usb_device *udev)
140 {
141 	/* USB 2.1 (and greater) devices indicate LPM support through
142 	 * their USB 2.0 Extended Capabilities BOS descriptor.
143 	 */
144 	if (udev->speed == USB_SPEED_HIGH) {
145 		if (udev->bos->ext_cap &&
146 			(USB_LPM_SUPPORT &
147 			 le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
148 			return 1;
149 		return 0;
150 	}
151 
152 	/* All USB 3.0 must support LPM, but we need their max exit latency
153 	 * information from the SuperSpeed Extended Capabilities BOS descriptor.
154 	 */
155 	if (!udev->bos->ss_cap) {
156 		dev_warn(&udev->dev, "No LPM exit latency info found.  "
157 				"Power management will be impacted.\n");
158 		return 0;
159 	}
160 	if (udev->parent->lpm_capable)
161 		return 1;
162 
163 	dev_warn(&udev->dev, "Parent hub missing LPM exit latency info.  "
164 			"Power management will be impacted.\n");
165 	return 0;
166 }
167 
168 /*
169  * Set the Maximum Exit Latency (MEL) for the host to initiate a transition from
170  * either U1 or U2.
171  */
usb_set_lpm_mel(struct usb_device * udev,struct usb3_lpm_parameters * udev_lpm_params,unsigned int udev_exit_latency,struct usb_hub * hub,struct usb3_lpm_parameters * hub_lpm_params,unsigned int hub_exit_latency)172 static void usb_set_lpm_mel(struct usb_device *udev,
173 		struct usb3_lpm_parameters *udev_lpm_params,
174 		unsigned int udev_exit_latency,
175 		struct usb_hub *hub,
176 		struct usb3_lpm_parameters *hub_lpm_params,
177 		unsigned int hub_exit_latency)
178 {
179 	unsigned int total_mel;
180 	unsigned int device_mel;
181 	unsigned int hub_mel;
182 
183 	/*
184 	 * Calculate the time it takes to transition all links from the roothub
185 	 * to the parent hub into U0.  The parent hub must then decode the
186 	 * packet (hub header decode latency) to figure out which port it was
187 	 * bound for.
188 	 *
189 	 * The Hub Header decode latency is expressed in 0.1us intervals (0x1
190 	 * means 0.1us).  Multiply that by 100 to get nanoseconds.
191 	 */
192 	total_mel = hub_lpm_params->mel +
193 		(hub->descriptor->u.ss.bHubHdrDecLat * 100);
194 
195 	/*
196 	 * How long will it take to transition the downstream hub's port into
197 	 * U0?  The greater of either the hub exit latency or the device exit
198 	 * latency.
199 	 *
200 	 * The BOS U1/U2 exit latencies are expressed in 1us intervals.
201 	 * Multiply that by 1000 to get nanoseconds.
202 	 */
203 	device_mel = udev_exit_latency * 1000;
204 	hub_mel = hub_exit_latency * 1000;
205 	if (device_mel > hub_mel)
206 		total_mel += device_mel;
207 	else
208 		total_mel += hub_mel;
209 
210 	udev_lpm_params->mel = total_mel;
211 }
212 
213 /*
214  * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
215  * a transition from either U1 or U2.
216  */
usb_set_lpm_pel(struct usb_device * udev,struct usb3_lpm_parameters * udev_lpm_params,unsigned int udev_exit_latency,struct usb_hub * hub,struct usb3_lpm_parameters * hub_lpm_params,unsigned int hub_exit_latency,unsigned int port_to_port_exit_latency)217 static void usb_set_lpm_pel(struct usb_device *udev,
218 		struct usb3_lpm_parameters *udev_lpm_params,
219 		unsigned int udev_exit_latency,
220 		struct usb_hub *hub,
221 		struct usb3_lpm_parameters *hub_lpm_params,
222 		unsigned int hub_exit_latency,
223 		unsigned int port_to_port_exit_latency)
224 {
225 	unsigned int first_link_pel;
226 	unsigned int hub_pel;
227 
228 	/*
229 	 * First, the device sends an LFPS to transition the link between the
230 	 * device and the parent hub into U0.  The exit latency is the bigger of
231 	 * the device exit latency or the hub exit latency.
232 	 */
233 	if (udev_exit_latency > hub_exit_latency)
234 		first_link_pel = udev_exit_latency * 1000;
235 	else
236 		first_link_pel = hub_exit_latency * 1000;
237 
238 	/*
239 	 * When the hub starts to receive the LFPS, there is a slight delay for
240 	 * it to figure out that one of the ports is sending an LFPS.  Then it
241 	 * will forward the LFPS to its upstream link.  The exit latency is the
242 	 * delay, plus the PEL that we calculated for this hub.
243 	 */
244 	hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;
245 
246 	/*
247 	 * According to figure C-7 in the USB 3.0 spec, the PEL for this device
248 	 * is the greater of the two exit latencies.
249 	 */
250 	if (first_link_pel > hub_pel)
251 		udev_lpm_params->pel = first_link_pel;
252 	else
253 		udev_lpm_params->pel = hub_pel;
254 }
255 
256 /*
257  * Set the System Exit Latency (SEL) to indicate the total worst-case time from
258  * when a device initiates a transition to U0, until when it will receive the
259  * first packet from the host controller.
260  *
261  * Section C.1.5.1 describes the four components to this:
262  *  - t1: device PEL
263  *  - t2: time for the ERDY to make it from the device to the host.
264  *  - t3: a host-specific delay to process the ERDY.
265  *  - t4: time for the packet to make it from the host to the device.
266  *
267  * t3 is specific to both the xHCI host and the platform the host is integrated
268  * into.  The Intel HW folks have said it's negligible, FIXME if a different
269  * vendor says otherwise.
270  */
usb_set_lpm_sel(struct usb_device * udev,struct usb3_lpm_parameters * udev_lpm_params)271 static void usb_set_lpm_sel(struct usb_device *udev,
272 		struct usb3_lpm_parameters *udev_lpm_params)
273 {
274 	struct usb_device *parent;
275 	unsigned int num_hubs;
276 	unsigned int total_sel;
277 
278 	/* t1 = device PEL */
279 	total_sel = udev_lpm_params->pel;
280 	/* How many external hubs are in between the device & the root port. */
281 	for (parent = udev->parent, num_hubs = 0; parent->parent;
282 			parent = parent->parent)
283 		num_hubs++;
284 	/* t2 = 2.1us + 250ns * (num_hubs - 1) */
285 	if (num_hubs > 0)
286 		total_sel += 2100 + 250 * (num_hubs - 1);
287 
288 	/* t4 = 250ns * num_hubs */
289 	total_sel += 250 * num_hubs;
290 
291 	udev_lpm_params->sel = total_sel;
292 }
293 
usb_set_lpm_parameters(struct usb_device * udev)294 static void usb_set_lpm_parameters(struct usb_device *udev)
295 {
296 	struct usb_hub *hub;
297 	unsigned int port_to_port_delay;
298 	unsigned int udev_u1_del;
299 	unsigned int udev_u2_del;
300 	unsigned int hub_u1_del;
301 	unsigned int hub_u2_del;
302 
303 	if (!udev->lpm_capable || udev->speed != USB_SPEED_SUPER)
304 		return;
305 
306 	hub = usb_hub_to_struct_hub(udev->parent);
307 	/* It doesn't take time to transition the roothub into U0, since it
308 	 * doesn't have an upstream link.
309 	 */
310 	if (!hub)
311 		return;
312 
313 	udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
314 	udev_u2_del = udev->bos->ss_cap->bU2DevExitLat;
315 	hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
316 	hub_u2_del = udev->parent->bos->ss_cap->bU2DevExitLat;
317 
318 	usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
319 			hub, &udev->parent->u1_params, hub_u1_del);
320 
321 	usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
322 			hub, &udev->parent->u2_params, hub_u2_del);
323 
324 	/*
325 	 * Appendix C, section C.2.2.2, says that there is a slight delay from
326 	 * when the parent hub notices the downstream port is trying to
327 	 * transition to U0 to when the hub initiates a U0 transition on its
328 	 * upstream port.  The section says the delays are tPort2PortU1EL and
329 	 * tPort2PortU2EL, but it doesn't define what they are.
330 	 *
331 	 * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
332 	 * about the same delays.  Use the maximum delay calculations from those
333 	 * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
334 	 * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
335 	 * assume the device exit latencies they are talking about are the hub
336 	 * exit latencies.
337 	 *
338 	 * What do we do if the U2 exit latency is less than the U1 exit
339 	 * latency?  It's possible, although not likely...
340 	 */
341 	port_to_port_delay = 1;
342 
343 	usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
344 			hub, &udev->parent->u1_params, hub_u1_del,
345 			port_to_port_delay);
346 
347 	if (hub_u2_del > hub_u1_del)
348 		port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
349 	else
350 		port_to_port_delay = 1 + hub_u1_del;
351 
352 	usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
353 			hub, &udev->parent->u2_params, hub_u2_del,
354 			port_to_port_delay);
355 
356 	/* Now that we've got PEL, calculate SEL. */
357 	usb_set_lpm_sel(udev, &udev->u1_params);
358 	usb_set_lpm_sel(udev, &udev->u2_params);
359 }
360 
361 /* USB 2.0 spec Section 11.24.4.5 */
get_hub_descriptor(struct usb_device * hdev,void * data)362 static int get_hub_descriptor(struct usb_device *hdev, void *data)
363 {
364 	int i, ret, size;
365 	unsigned dtype;
366 
367 	if (hub_is_superspeed(hdev)) {
368 		dtype = USB_DT_SS_HUB;
369 		size = USB_DT_SS_HUB_SIZE;
370 	} else {
371 		dtype = USB_DT_HUB;
372 		size = sizeof(struct usb_hub_descriptor);
373 	}
374 
375 	for (i = 0; i < 3; i++) {
376 		ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
377 			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
378 			dtype << 8, 0, data, size,
379 			USB_CTRL_GET_TIMEOUT);
380 		if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
381 			return ret;
382 	}
383 	return -EINVAL;
384 }
385 
386 /*
387  * USB 2.0 spec Section 11.24.2.1
388  */
clear_hub_feature(struct usb_device * hdev,int feature)389 static int clear_hub_feature(struct usb_device *hdev, int feature)
390 {
391 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
392 		USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
393 }
394 
395 /*
396  * USB 2.0 spec Section 11.24.2.2
397  */
usb_clear_port_feature(struct usb_device * hdev,int port1,int feature)398 int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
399 {
400 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
401 		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
402 		NULL, 0, 1000);
403 }
404 
405 /*
406  * USB 2.0 spec Section 11.24.2.13
407  */
set_port_feature(struct usb_device * hdev,int port1,int feature)408 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
409 {
410 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
411 		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
412 		NULL, 0, 1000);
413 }
414 
415 /*
416  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
417  * for info about using port indicators
418  */
set_port_led(struct usb_hub * hub,int port1,int selector)419 static void set_port_led(
420 	struct usb_hub *hub,
421 	int port1,
422 	int selector
423 )
424 {
425 	int status = set_port_feature(hub->hdev, (selector << 8) | port1,
426 			USB_PORT_FEAT_INDICATOR);
427 	if (status < 0)
428 		dev_dbg (hub->intfdev,
429 			"port %d indicator %s status %d\n",
430 			port1,
431 			({ char *s; switch (selector) {
432 			case HUB_LED_AMBER: s = "amber"; break;
433 			case HUB_LED_GREEN: s = "green"; break;
434 			case HUB_LED_OFF: s = "off"; break;
435 			case HUB_LED_AUTO: s = "auto"; break;
436 			default: s = "??"; break;
437 			}; s; }),
438 			status);
439 }
440 
441 #define	LED_CYCLE_PERIOD	((2*HZ)/3)
442 
led_work(struct work_struct * work)443 static void led_work (struct work_struct *work)
444 {
445 	struct usb_hub		*hub =
446 		container_of(work, struct usb_hub, leds.work);
447 	struct usb_device	*hdev = hub->hdev;
448 	unsigned		i;
449 	unsigned		changed = 0;
450 	int			cursor = -1;
451 
452 	if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
453 		return;
454 
455 	for (i = 0; i < hub->descriptor->bNbrPorts; i++) {
456 		unsigned	selector, mode;
457 
458 		/* 30%-50% duty cycle */
459 
460 		switch (hub->indicator[i]) {
461 		/* cycle marker */
462 		case INDICATOR_CYCLE:
463 			cursor = i;
464 			selector = HUB_LED_AUTO;
465 			mode = INDICATOR_AUTO;
466 			break;
467 		/* blinking green = sw attention */
468 		case INDICATOR_GREEN_BLINK:
469 			selector = HUB_LED_GREEN;
470 			mode = INDICATOR_GREEN_BLINK_OFF;
471 			break;
472 		case INDICATOR_GREEN_BLINK_OFF:
473 			selector = HUB_LED_OFF;
474 			mode = INDICATOR_GREEN_BLINK;
475 			break;
476 		/* blinking amber = hw attention */
477 		case INDICATOR_AMBER_BLINK:
478 			selector = HUB_LED_AMBER;
479 			mode = INDICATOR_AMBER_BLINK_OFF;
480 			break;
481 		case INDICATOR_AMBER_BLINK_OFF:
482 			selector = HUB_LED_OFF;
483 			mode = INDICATOR_AMBER_BLINK;
484 			break;
485 		/* blink green/amber = reserved */
486 		case INDICATOR_ALT_BLINK:
487 			selector = HUB_LED_GREEN;
488 			mode = INDICATOR_ALT_BLINK_OFF;
489 			break;
490 		case INDICATOR_ALT_BLINK_OFF:
491 			selector = HUB_LED_AMBER;
492 			mode = INDICATOR_ALT_BLINK;
493 			break;
494 		default:
495 			continue;
496 		}
497 		if (selector != HUB_LED_AUTO)
498 			changed = 1;
499 		set_port_led(hub, i + 1, selector);
500 		hub->indicator[i] = mode;
501 	}
502 	if (!changed && blinkenlights) {
503 		cursor++;
504 		cursor %= hub->descriptor->bNbrPorts;
505 		set_port_led(hub, cursor + 1, HUB_LED_GREEN);
506 		hub->indicator[cursor] = INDICATOR_CYCLE;
507 		changed++;
508 	}
509 	if (changed)
510 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
511 }
512 
513 /* use a short timeout for hub/port status fetches */
514 #define	USB_STS_TIMEOUT		1000
515 #define	USB_STS_RETRIES		5
516 
517 /*
518  * USB 2.0 spec Section 11.24.2.6
519  */
get_hub_status(struct usb_device * hdev,struct usb_hub_status * data)520 static int get_hub_status(struct usb_device *hdev,
521 		struct usb_hub_status *data)
522 {
523 	int i, status = -ETIMEDOUT;
524 
525 	for (i = 0; i < USB_STS_RETRIES &&
526 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
527 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
528 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
529 			data, sizeof(*data), USB_STS_TIMEOUT);
530 	}
531 	return status;
532 }
533 
534 /*
535  * USB 2.0 spec Section 11.24.2.7
536  */
get_port_status(struct usb_device * hdev,int port1,struct usb_port_status * data)537 static int get_port_status(struct usb_device *hdev, int port1,
538 		struct usb_port_status *data)
539 {
540 	int i, status = -ETIMEDOUT;
541 
542 	for (i = 0; i < USB_STS_RETRIES &&
543 			(status == -ETIMEDOUT || status == -EPIPE); i++) {
544 		status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
545 			USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1,
546 			data, sizeof(*data), USB_STS_TIMEOUT);
547 	}
548 	return status;
549 }
550 
hub_port_status(struct usb_hub * hub,int port1,u16 * status,u16 * change)551 static int hub_port_status(struct usb_hub *hub, int port1,
552 		u16 *status, u16 *change)
553 {
554 	int ret;
555 
556 	mutex_lock(&hub->status_mutex);
557 	ret = get_port_status(hub->hdev, port1, &hub->status->port);
558 	if (ret < 4) {
559 		if (ret != -ENODEV)
560 			dev_err(hub->intfdev,
561 				"%s failed (err = %d)\n", __func__, ret);
562 		if (ret >= 0)
563 			ret = -EIO;
564 	} else {
565 		*status = le16_to_cpu(hub->status->port.wPortStatus);
566 		*change = le16_to_cpu(hub->status->port.wPortChange);
567 
568 		ret = 0;
569 	}
570 	mutex_unlock(&hub->status_mutex);
571 	return ret;
572 }
573 
kick_khubd(struct usb_hub * hub)574 static void kick_khubd(struct usb_hub *hub)
575 {
576 	unsigned long	flags;
577 
578 	spin_lock_irqsave(&hub_event_lock, flags);
579 	if (!hub->disconnected && list_empty(&hub->event_list)) {
580 		list_add_tail(&hub->event_list, &hub_event_list);
581 
582 		/* Suppress autosuspend until khubd runs */
583 		usb_autopm_get_interface_no_resume(
584 				to_usb_interface(hub->intfdev));
585 		wake_up(&khubd_wait);
586 	}
587 	spin_unlock_irqrestore(&hub_event_lock, flags);
588 }
589 
usb_kick_khubd(struct usb_device * hdev)590 void usb_kick_khubd(struct usb_device *hdev)
591 {
592 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
593 
594 	if (hub)
595 		kick_khubd(hub);
596 }
597 
598 /*
599  * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
600  * Notification, which indicates it had initiated remote wakeup.
601  *
602  * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
603  * device initiates resume, so the USB core will not receive notice of the
604  * resume through the normal hub interrupt URB.
605  */
usb_wakeup_notification(struct usb_device * hdev,unsigned int portnum)606 void usb_wakeup_notification(struct usb_device *hdev,
607 		unsigned int portnum)
608 {
609 	struct usb_hub *hub;
610 
611 	if (!hdev)
612 		return;
613 
614 	hub = usb_hub_to_struct_hub(hdev);
615 	if (hub) {
616 		set_bit(portnum, hub->wakeup_bits);
617 		kick_khubd(hub);
618 	}
619 }
620 EXPORT_SYMBOL_GPL(usb_wakeup_notification);
621 
622 /* completion function, fires on port status changes and various faults */
hub_irq(struct urb * urb)623 static void hub_irq(struct urb *urb)
624 {
625 	struct usb_hub *hub = urb->context;
626 	int status = urb->status;
627 	unsigned i;
628 	unsigned long bits;
629 
630 	switch (status) {
631 	case -ENOENT:		/* synchronous unlink */
632 	case -ECONNRESET:	/* async unlink */
633 	case -ESHUTDOWN:	/* hardware going away */
634 		return;
635 
636 	default:		/* presumably an error */
637 		/* Cause a hub reset after 10 consecutive errors */
638 		dev_dbg (hub->intfdev, "transfer --> %d\n", status);
639 		if ((++hub->nerrors < 10) || hub->error)
640 			goto resubmit;
641 		hub->error = status;
642 		/* FALL THROUGH */
643 
644 	/* let khubd handle things */
645 	case 0:			/* we got data:  port status changed */
646 		bits = 0;
647 		for (i = 0; i < urb->actual_length; ++i)
648 			bits |= ((unsigned long) ((*hub->buffer)[i]))
649 					<< (i*8);
650 		hub->event_bits[0] = bits;
651 		break;
652 	}
653 
654 	hub->nerrors = 0;
655 
656 	/* Something happened, let khubd figure it out */
657 	kick_khubd(hub);
658 
659 resubmit:
660 	if (hub->quiescing)
661 		return;
662 
663 	if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0
664 			&& status != -ENODEV && status != -EPERM)
665 		dev_err (hub->intfdev, "resubmit --> %d\n", status);
666 }
667 
668 /* USB 2.0 spec Section 11.24.2.3 */
669 static inline int
hub_clear_tt_buffer(struct usb_device * hdev,u16 devinfo,u16 tt)670 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
671 {
672 	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
673 			       HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
674 			       tt, NULL, 0, 1000);
675 }
676 
677 /*
678  * enumeration blocks khubd for a long time. we use keventd instead, since
679  * long blocking there is the exception, not the rule.  accordingly, HCDs
680  * talking to TTs must queue control transfers (not just bulk and iso), so
681  * both can talk to the same hub concurrently.
682  */
hub_tt_work(struct work_struct * work)683 static void hub_tt_work(struct work_struct *work)
684 {
685 	struct usb_hub		*hub =
686 		container_of(work, struct usb_hub, tt.clear_work);
687 	unsigned long		flags;
688 
689 	spin_lock_irqsave (&hub->tt.lock, flags);
690 	while (!list_empty(&hub->tt.clear_list)) {
691 		struct list_head	*next;
692 		struct usb_tt_clear	*clear;
693 		struct usb_device	*hdev = hub->hdev;
694 		const struct hc_driver	*drv;
695 		int			status;
696 
697 		next = hub->tt.clear_list.next;
698 		clear = list_entry (next, struct usb_tt_clear, clear_list);
699 		list_del (&clear->clear_list);
700 
701 		/* drop lock so HCD can concurrently report other TT errors */
702 		spin_unlock_irqrestore (&hub->tt.lock, flags);
703 		status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt);
704 		if (status && status != -ENODEV)
705 			dev_err (&hdev->dev,
706 				"clear tt %d (%04x) error %d\n",
707 				clear->tt, clear->devinfo, status);
708 
709 		/* Tell the HCD, even if the operation failed */
710 		drv = clear->hcd->driver;
711 		if (drv->clear_tt_buffer_complete)
712 			(drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
713 
714 		kfree(clear);
715 		spin_lock_irqsave(&hub->tt.lock, flags);
716 	}
717 	spin_unlock_irqrestore (&hub->tt.lock, flags);
718 }
719 
720 /**
721  * usb_hub_set_port_power - control hub port's power state
722  * @hdev: target hub
723  * @port1: port index
724  * @set: expected status
725  *
726  * call this function to control port's power via setting or
727  * clearing the port's PORT_POWER feature.
728  */
usb_hub_set_port_power(struct usb_device * hdev,int port1,bool set)729 int usb_hub_set_port_power(struct usb_device *hdev, int port1,
730 		bool set)
731 {
732 	int ret;
733 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
734 	struct usb_port *port_dev = hub->ports[port1 - 1];
735 
736 	if (set)
737 		ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
738 	else
739 		ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
740 
741 	if (!ret)
742 		port_dev->power_is_on = set;
743 	return ret;
744 }
745 
746 /**
747  * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
748  * @urb: an URB associated with the failed or incomplete split transaction
749  *
750  * High speed HCDs use this to tell the hub driver that some split control or
751  * bulk transaction failed in a way that requires clearing internal state of
752  * a transaction translator.  This is normally detected (and reported) from
753  * interrupt context.
754  *
755  * It may not be possible for that hub to handle additional full (or low)
756  * speed transactions until that state is fully cleared out.
757  */
usb_hub_clear_tt_buffer(struct urb * urb)758 int usb_hub_clear_tt_buffer(struct urb *urb)
759 {
760 	struct usb_device	*udev = urb->dev;
761 	int			pipe = urb->pipe;
762 	struct usb_tt		*tt = udev->tt;
763 	unsigned long		flags;
764 	struct usb_tt_clear	*clear;
765 
766 	/* we've got to cope with an arbitrary number of pending TT clears,
767 	 * since each TT has "at least two" buffers that can need it (and
768 	 * there can be many TTs per hub).  even if they're uncommon.
769 	 */
770 	if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) {
771 		dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
772 		/* FIXME recover somehow ... RESET_TT? */
773 		return -ENOMEM;
774 	}
775 
776 	/* info that CLEAR_TT_BUFFER needs */
777 	clear->tt = tt->multi ? udev->ttport : 1;
778 	clear->devinfo = usb_pipeendpoint (pipe);
779 	clear->devinfo |= udev->devnum << 4;
780 	clear->devinfo |= usb_pipecontrol (pipe)
781 			? (USB_ENDPOINT_XFER_CONTROL << 11)
782 			: (USB_ENDPOINT_XFER_BULK << 11);
783 	if (usb_pipein (pipe))
784 		clear->devinfo |= 1 << 15;
785 
786 	/* info for completion callback */
787 	clear->hcd = bus_to_hcd(udev->bus);
788 	clear->ep = urb->ep;
789 
790 	/* tell keventd to clear state for this TT */
791 	spin_lock_irqsave (&tt->lock, flags);
792 	list_add_tail (&clear->clear_list, &tt->clear_list);
793 	schedule_work(&tt->clear_work);
794 	spin_unlock_irqrestore (&tt->lock, flags);
795 	return 0;
796 }
797 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
798 
799 /* If do_delay is false, return the number of milliseconds the caller
800  * needs to delay.
801  */
hub_power_on(struct usb_hub * hub,bool do_delay)802 static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
803 {
804 	int port1;
805 	unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
806 	unsigned delay;
807 	u16 wHubCharacteristics =
808 			le16_to_cpu(hub->descriptor->wHubCharacteristics);
809 
810 	/* Enable power on each port.  Some hubs have reserved values
811 	 * of LPSM (> 2) in their descriptors, even though they are
812 	 * USB 2.0 hubs.  Some hubs do not implement port-power switching
813 	 * but only emulate it.  In all cases, the ports won't work
814 	 * unless we send these messages to the hub.
815 	 */
816 	if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2)
817 		dev_dbg(hub->intfdev, "enabling power on all ports\n");
818 	else
819 		dev_dbg(hub->intfdev, "trying to enable port power on "
820 				"non-switchable hub\n");
821 	for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++)
822 		if (hub->ports[port1 - 1]->power_is_on)
823 			set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
824 		else
825 			usb_clear_port_feature(hub->hdev, port1,
826 						USB_PORT_FEAT_POWER);
827 
828 	/* Wait at least 100 msec for power to become stable */
829 	delay = max(pgood_delay, (unsigned) 100);
830 	if (do_delay)
831 		msleep(delay);
832 	return delay;
833 }
834 
hub_hub_status(struct usb_hub * hub,u16 * status,u16 * change)835 static int hub_hub_status(struct usb_hub *hub,
836 		u16 *status, u16 *change)
837 {
838 	int ret;
839 
840 	mutex_lock(&hub->status_mutex);
841 	ret = get_hub_status(hub->hdev, &hub->status->hub);
842 	if (ret < 0) {
843 		if (ret != -ENODEV)
844 			dev_err(hub->intfdev,
845 				"%s failed (err = %d)\n", __func__, ret);
846 	} else {
847 		*status = le16_to_cpu(hub->status->hub.wHubStatus);
848 		*change = le16_to_cpu(hub->status->hub.wHubChange);
849 		ret = 0;
850 	}
851 	mutex_unlock(&hub->status_mutex);
852 	return ret;
853 }
854 
hub_set_port_link_state(struct usb_hub * hub,int port1,unsigned int link_status)855 static int hub_set_port_link_state(struct usb_hub *hub, int port1,
856 			unsigned int link_status)
857 {
858 	return set_port_feature(hub->hdev,
859 			port1 | (link_status << 3),
860 			USB_PORT_FEAT_LINK_STATE);
861 }
862 
863 /*
864  * If USB 3.0 ports are placed into the Disabled state, they will no longer
865  * detect any device connects or disconnects.  This is generally not what the
866  * USB core wants, since it expects a disabled port to produce a port status
867  * change event when a new device connects.
868  *
869  * Instead, set the link state to Disabled, wait for the link to settle into
870  * that state, clear any change bits, and then put the port into the RxDetect
871  * state.
872  */
hub_usb3_port_disable(struct usb_hub * hub,int port1)873 static int hub_usb3_port_disable(struct usb_hub *hub, int port1)
874 {
875 	int ret;
876 	int total_time;
877 	u16 portchange, portstatus;
878 
879 	if (!hub_is_superspeed(hub->hdev))
880 		return -EINVAL;
881 
882 	ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED);
883 	if (ret)
884 		return ret;
885 
886 	/* Wait for the link to enter the disabled state. */
887 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
888 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
889 		if (ret < 0)
890 			return ret;
891 
892 		if ((portstatus & USB_PORT_STAT_LINK_STATE) ==
893 				USB_SS_PORT_LS_SS_DISABLED)
894 			break;
895 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
896 			break;
897 		msleep(HUB_DEBOUNCE_STEP);
898 	}
899 	if (total_time >= HUB_DEBOUNCE_TIMEOUT)
900 		dev_warn(hub->intfdev, "Could not disable port %d after %d ms\n",
901 				port1, total_time);
902 
903 	return hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_RX_DETECT);
904 }
905 
hub_port_disable(struct usb_hub * hub,int port1,int set_state)906 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
907 {
908 	struct usb_device *hdev = hub->hdev;
909 	int ret = 0;
910 
911 	if (hub->ports[port1 - 1]->child && set_state)
912 		usb_set_device_state(hub->ports[port1 - 1]->child,
913 				USB_STATE_NOTATTACHED);
914 	if (!hub->error) {
915 		if (hub_is_superspeed(hub->hdev))
916 			ret = hub_usb3_port_disable(hub, port1);
917 		else
918 			ret = usb_clear_port_feature(hdev, port1,
919 					USB_PORT_FEAT_ENABLE);
920 	}
921 	if (ret && ret != -ENODEV)
922 		dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n",
923 				port1, ret);
924 	return ret;
925 }
926 
927 /*
928  * Disable a port and mark a logical connect-change event, so that some
929  * time later khubd will disconnect() any existing usb_device on the port
930  * and will re-enumerate if there actually is a device attached.
931  */
hub_port_logical_disconnect(struct usb_hub * hub,int port1)932 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
933 {
934 	dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1);
935 	hub_port_disable(hub, port1, 1);
936 
937 	/* FIXME let caller ask to power down the port:
938 	 *  - some devices won't enumerate without a VBUS power cycle
939 	 *  - SRP saves power that way
940 	 *  - ... new call, TBD ...
941 	 * That's easy if this hub can switch power per-port, and
942 	 * khubd reactivates the port later (timer, SRP, etc).
943 	 * Powerdown must be optional, because of reset/DFU.
944 	 */
945 
946 	set_bit(port1, hub->change_bits);
947  	kick_khubd(hub);
948 }
949 
950 /**
951  * usb_remove_device - disable a device's port on its parent hub
952  * @udev: device to be disabled and removed
953  * Context: @udev locked, must be able to sleep.
954  *
955  * After @udev's port has been disabled, khubd is notified and it will
956  * see that the device has been disconnected.  When the device is
957  * physically unplugged and something is plugged in, the events will
958  * be received and processed normally.
959  */
usb_remove_device(struct usb_device * udev)960 int usb_remove_device(struct usb_device *udev)
961 {
962 	struct usb_hub *hub;
963 	struct usb_interface *intf;
964 
965 	if (!udev->parent)	/* Can't remove a root hub */
966 		return -EINVAL;
967 	hub = usb_hub_to_struct_hub(udev->parent);
968 	intf = to_usb_interface(hub->intfdev);
969 
970 	usb_autopm_get_interface(intf);
971 	set_bit(udev->portnum, hub->removed_bits);
972 	hub_port_logical_disconnect(hub, udev->portnum);
973 	usb_autopm_put_interface(intf);
974 	return 0;
975 }
976 
977 enum hub_activation_type {
978 	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */
979 	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
980 };
981 
982 static void hub_init_func2(struct work_struct *ws);
983 static void hub_init_func3(struct work_struct *ws);
984 
hub_activate(struct usb_hub * hub,enum hub_activation_type type)985 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
986 {
987 	struct usb_device *hdev = hub->hdev;
988 	struct usb_hcd *hcd;
989 	int ret;
990 	int port1;
991 	int status;
992 	bool need_debounce_delay = false;
993 	unsigned delay;
994 
995 	/* Continue a partial initialization */
996 	if (type == HUB_INIT2 || type == HUB_INIT3) {
997 		device_lock(hub->intfdev);
998 
999 		/* Was the hub disconnected while we were waiting? */
1000 		if (hub->disconnected) {
1001 			device_unlock(hub->intfdev);
1002 			kref_put(&hub->kref, hub_release);
1003 			return;
1004 		}
1005 		if (type == HUB_INIT2)
1006 			goto init2;
1007 		goto init3;
1008 	}
1009 	kref_get(&hub->kref);
1010 
1011 	/* The superspeed hub except for root hub has to use Hub Depth
1012 	 * value as an offset into the route string to locate the bits
1013 	 * it uses to determine the downstream port number. So hub driver
1014 	 * should send a set hub depth request to superspeed hub after
1015 	 * the superspeed hub is set configuration in initialization or
1016 	 * reset procedure.
1017 	 *
1018 	 * After a resume, port power should still be on.
1019 	 * For any other type of activation, turn it on.
1020 	 */
1021 	if (type != HUB_RESUME) {
1022 		if (hdev->parent && hub_is_superspeed(hdev)) {
1023 			ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
1024 					HUB_SET_DEPTH, USB_RT_HUB,
1025 					hdev->level - 1, 0, NULL, 0,
1026 					USB_CTRL_SET_TIMEOUT);
1027 			if (ret < 0)
1028 				dev_err(hub->intfdev,
1029 						"set hub depth failed\n");
1030 		}
1031 
1032 		/* Speed up system boot by using a delayed_work for the
1033 		 * hub's initial power-up delays.  This is pretty awkward
1034 		 * and the implementation looks like a home-brewed sort of
1035 		 * setjmp/longjmp, but it saves at least 100 ms for each
1036 		 * root hub (assuming usbcore is compiled into the kernel
1037 		 * rather than as a module).  It adds up.
1038 		 *
1039 		 * This can't be done for HUB_RESUME or HUB_RESET_RESUME
1040 		 * because for those activation types the ports have to be
1041 		 * operational when we return.  In theory this could be done
1042 		 * for HUB_POST_RESET, but it's easier not to.
1043 		 */
1044 		if (type == HUB_INIT) {
1045 			delay = hub_power_on(hub, false);
1046 			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
1047 			schedule_delayed_work(&hub->init_work,
1048 					msecs_to_jiffies(delay));
1049 
1050 			/* Suppress autosuspend until init is done */
1051 			usb_autopm_get_interface_no_resume(
1052 					to_usb_interface(hub->intfdev));
1053 			return;		/* Continues at init2: below */
1054 		} else if (type == HUB_RESET_RESUME) {
1055 			/* The internal host controller state for the hub device
1056 			 * may be gone after a host power loss on system resume.
1057 			 * Update the device's info so the HW knows it's a hub.
1058 			 */
1059 			hcd = bus_to_hcd(hdev->bus);
1060 			if (hcd->driver->update_hub_device) {
1061 				ret = hcd->driver->update_hub_device(hcd, hdev,
1062 						&hub->tt, GFP_NOIO);
1063 				if (ret < 0) {
1064 					dev_err(hub->intfdev, "Host not "
1065 							"accepting hub info "
1066 							"update.\n");
1067 					dev_err(hub->intfdev, "LS/FS devices "
1068 							"and hubs may not work "
1069 							"under this hub\n.");
1070 				}
1071 			}
1072 			hub_power_on(hub, true);
1073 		} else {
1074 			hub_power_on(hub, true);
1075 		}
1076 	}
1077  init2:
1078 
1079 	/* Check each port and set hub->change_bits to let khubd know
1080 	 * which ports need attention.
1081 	 */
1082 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1083 		struct usb_device *udev = hub->ports[port1 - 1]->child;
1084 		u16 portstatus, portchange;
1085 
1086 		portstatus = portchange = 0;
1087 		status = hub_port_status(hub, port1, &portstatus, &portchange);
1088 		if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1089 			dev_dbg(hub->intfdev,
1090 					"port %d: status %04x change %04x\n",
1091 					port1, portstatus, portchange);
1092 
1093 		/* After anything other than HUB_RESUME (i.e., initialization
1094 		 * or any sort of reset), every port should be disabled.
1095 		 * Unconnected ports should likewise be disabled (paranoia),
1096 		 * and so should ports for which we have no usb_device.
1097 		 */
1098 		if ((portstatus & USB_PORT_STAT_ENABLE) && (
1099 				type != HUB_RESUME ||
1100 				!(portstatus & USB_PORT_STAT_CONNECTION) ||
1101 				!udev ||
1102 				udev->state == USB_STATE_NOTATTACHED)) {
1103 			/*
1104 			 * USB3 protocol ports will automatically transition
1105 			 * to Enabled state when detect an USB3.0 device attach.
1106 			 * Do not disable USB3 protocol ports.
1107 			 */
1108 			if (!hub_is_superspeed(hdev)) {
1109 				usb_clear_port_feature(hdev, port1,
1110 						   USB_PORT_FEAT_ENABLE);
1111 				portstatus &= ~USB_PORT_STAT_ENABLE;
1112 			} else {
1113 				/* Pretend that power was lost for USB3 devs */
1114 				portstatus &= ~USB_PORT_STAT_ENABLE;
1115 			}
1116 		}
1117 
1118 		/* Clear status-change flags; we'll debounce later */
1119 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
1120 			need_debounce_delay = true;
1121 			usb_clear_port_feature(hub->hdev, port1,
1122 					USB_PORT_FEAT_C_CONNECTION);
1123 		}
1124 		if (portchange & USB_PORT_STAT_C_ENABLE) {
1125 			need_debounce_delay = true;
1126 			usb_clear_port_feature(hub->hdev, port1,
1127 					USB_PORT_FEAT_C_ENABLE);
1128 		}
1129 		if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
1130 				hub_is_superspeed(hub->hdev)) {
1131 			need_debounce_delay = true;
1132 			usb_clear_port_feature(hub->hdev, port1,
1133 					USB_PORT_FEAT_C_BH_PORT_RESET);
1134 		}
1135 		/* We can forget about a "removed" device when there's a
1136 		 * physical disconnect or the connect status changes.
1137 		 */
1138 		if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
1139 				(portchange & USB_PORT_STAT_C_CONNECTION))
1140 			clear_bit(port1, hub->removed_bits);
1141 
1142 		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
1143 			/* Tell khubd to disconnect the device or
1144 			 * check for a new connection
1145 			 */
1146 			if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1147 				set_bit(port1, hub->change_bits);
1148 
1149 		} else if (portstatus & USB_PORT_STAT_ENABLE) {
1150 			bool port_resumed = (portstatus &
1151 					USB_PORT_STAT_LINK_STATE) ==
1152 				USB_SS_PORT_LS_U0;
1153 			/* The power session apparently survived the resume.
1154 			 * If there was an overcurrent or suspend change
1155 			 * (i.e., remote wakeup request), have khubd
1156 			 * take care of it.  Look at the port link state
1157 			 * for USB 3.0 hubs, since they don't have a suspend
1158 			 * change bit, and they don't set the port link change
1159 			 * bit on device-initiated resume.
1160 			 */
1161 			if (portchange || (hub_is_superspeed(hub->hdev) &&
1162 						port_resumed))
1163 				set_bit(port1, hub->change_bits);
1164 
1165 		} else if (udev->persist_enabled) {
1166 			struct usb_port *port_dev = hub->ports[port1 - 1];
1167 
1168 #ifdef CONFIG_PM
1169 			udev->reset_resume = 1;
1170 #endif
1171 			/* Don't set the change_bits when the device
1172 			 * was powered off.
1173 			 */
1174 			if (port_dev->power_is_on)
1175 				set_bit(port1, hub->change_bits);
1176 
1177 		} else {
1178 			/* The power session is gone; tell khubd */
1179 			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1180 			set_bit(port1, hub->change_bits);
1181 		}
1182 	}
1183 
1184 	/* If no port-status-change flags were set, we don't need any
1185 	 * debouncing.  If flags were set we can try to debounce the
1186 	 * ports all at once right now, instead of letting khubd do them
1187 	 * one at a time later on.
1188 	 *
1189 	 * If any port-status changes do occur during this delay, khubd
1190 	 * will see them later and handle them normally.
1191 	 */
1192 	if (need_debounce_delay) {
1193 		delay = HUB_DEBOUNCE_STABLE;
1194 
1195 		/* Don't do a long sleep inside a workqueue routine */
1196 		if (type == HUB_INIT2) {
1197 			PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
1198 			schedule_delayed_work(&hub->init_work,
1199 					msecs_to_jiffies(delay));
1200 			device_unlock(hub->intfdev);
1201 			return;		/* Continues at init3: below */
1202 		} else {
1203 			msleep(delay);
1204 		}
1205 	}
1206  init3:
1207 	hub->quiescing = 0;
1208 
1209 	status = usb_submit_urb(hub->urb, GFP_NOIO);
1210 	if (status < 0)
1211 		dev_err(hub->intfdev, "activate --> %d\n", status);
1212 	if (hub->has_indicators && blinkenlights)
1213 		schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD);
1214 
1215 	/* Scan all ports that need attention */
1216 	kick_khubd(hub);
1217 
1218 	/* Allow autosuspend if it was suppressed */
1219 	if (type <= HUB_INIT3)
1220 		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
1221 
1222 	if (type == HUB_INIT2 || type == HUB_INIT3)
1223 		device_unlock(hub->intfdev);
1224 
1225 	kref_put(&hub->kref, hub_release);
1226 }
1227 
1228 /* Implement the continuations for the delays above */
hub_init_func2(struct work_struct * ws)1229 static void hub_init_func2(struct work_struct *ws)
1230 {
1231 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1232 
1233 	hub_activate(hub, HUB_INIT2);
1234 }
1235 
hub_init_func3(struct work_struct * ws)1236 static void hub_init_func3(struct work_struct *ws)
1237 {
1238 	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1239 
1240 	hub_activate(hub, HUB_INIT3);
1241 }
1242 
1243 enum hub_quiescing_type {
1244 	HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
1245 };
1246 
hub_quiesce(struct usb_hub * hub,enum hub_quiescing_type type)1247 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
1248 {
1249 	struct usb_device *hdev = hub->hdev;
1250 	int i;
1251 
1252 	cancel_delayed_work_sync(&hub->init_work);
1253 
1254 	/* khubd and related activity won't re-trigger */
1255 	hub->quiescing = 1;
1256 
1257 	if (type != HUB_SUSPEND) {
1258 		/* Disconnect all the children */
1259 		for (i = 0; i < hdev->maxchild; ++i) {
1260 			if (hub->ports[i]->child)
1261 				usb_disconnect(&hub->ports[i]->child);
1262 		}
1263 	}
1264 
1265 	/* Stop khubd and related activity */
1266 	usb_kill_urb(hub->urb);
1267 	if (hub->has_indicators)
1268 		cancel_delayed_work_sync(&hub->leds);
1269 	if (hub->tt.hub)
1270 		flush_work(&hub->tt.clear_work);
1271 }
1272 
1273 /* caller has locked the hub device */
hub_pre_reset(struct usb_interface * intf)1274 static int hub_pre_reset(struct usb_interface *intf)
1275 {
1276 	struct usb_hub *hub = usb_get_intfdata(intf);
1277 
1278 	hub_quiesce(hub, HUB_PRE_RESET);
1279 	return 0;
1280 }
1281 
1282 /* caller has locked the hub device */
hub_post_reset(struct usb_interface * intf)1283 static int hub_post_reset(struct usb_interface *intf)
1284 {
1285 	struct usb_hub *hub = usb_get_intfdata(intf);
1286 
1287 	hub_activate(hub, HUB_POST_RESET);
1288 	return 0;
1289 }
1290 
hub_configure(struct usb_hub * hub,struct usb_endpoint_descriptor * endpoint)1291 static int hub_configure(struct usb_hub *hub,
1292 	struct usb_endpoint_descriptor *endpoint)
1293 {
1294 	struct usb_hcd *hcd;
1295 	struct usb_device *hdev = hub->hdev;
1296 	struct device *hub_dev = hub->intfdev;
1297 	u16 hubstatus, hubchange;
1298 	u16 wHubCharacteristics;
1299 	unsigned int pipe;
1300 	int maxp, ret, i;
1301 	char *message = "out of memory";
1302 	unsigned unit_load;
1303 	unsigned full_load;
1304 
1305 	hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
1306 	if (!hub->buffer) {
1307 		ret = -ENOMEM;
1308 		goto fail;
1309 	}
1310 
1311 	hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
1312 	if (!hub->status) {
1313 		ret = -ENOMEM;
1314 		goto fail;
1315 	}
1316 	mutex_init(&hub->status_mutex);
1317 
1318 	hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL);
1319 	if (!hub->descriptor) {
1320 		ret = -ENOMEM;
1321 		goto fail;
1322 	}
1323 
1324 	/* Request the entire hub descriptor.
1325 	 * hub->descriptor can handle USB_MAXCHILDREN ports,
1326 	 * but the hub can/will return fewer bytes here.
1327 	 */
1328 	ret = get_hub_descriptor(hdev, hub->descriptor);
1329 	if (ret < 0) {
1330 		message = "can't read hub descriptor";
1331 		goto fail;
1332 	} else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
1333 		message = "hub has too many ports!";
1334 		ret = -ENODEV;
1335 		goto fail;
1336 	} else if (hub->descriptor->bNbrPorts == 0) {
1337 		message = "hub doesn't have any ports!";
1338 		ret = -ENODEV;
1339 		goto fail;
1340 	}
1341 
1342 	hdev->maxchild = hub->descriptor->bNbrPorts;
1343 	dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild,
1344 		(hdev->maxchild == 1) ? "" : "s");
1345 
1346 	hub->ports = kzalloc(hdev->maxchild * sizeof(struct usb_port *),
1347 			     GFP_KERNEL);
1348 	if (!hub->ports) {
1349 		ret = -ENOMEM;
1350 		goto fail;
1351 	}
1352 
1353 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
1354 	if (hub_is_superspeed(hdev)) {
1355 		unit_load = 150;
1356 		full_load = 900;
1357 	} else {
1358 		unit_load = 100;
1359 		full_load = 500;
1360 	}
1361 
1362 	/* FIXME for USB 3.0, skip for now */
1363 	if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
1364 			!(hub_is_superspeed(hdev))) {
1365 		int	i;
1366 		char	portstr [USB_MAXCHILDREN + 1];
1367 
1368 		for (i = 0; i < hdev->maxchild; i++)
1369 			portstr[i] = hub->descriptor->u.hs.DeviceRemovable
1370 				    [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1371 				? 'F' : 'R';
1372 		portstr[hdev->maxchild] = 0;
1373 		dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1374 	} else
1375 		dev_dbg(hub_dev, "standalone hub\n");
1376 
1377 	switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1378 	case HUB_CHAR_COMMON_LPSM:
1379 		dev_dbg(hub_dev, "ganged power switching\n");
1380 		break;
1381 	case HUB_CHAR_INDV_PORT_LPSM:
1382 		dev_dbg(hub_dev, "individual port power switching\n");
1383 		break;
1384 	case HUB_CHAR_NO_LPSM:
1385 	case HUB_CHAR_LPSM:
1386 		dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1387 		break;
1388 	}
1389 
1390 	switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1391 	case HUB_CHAR_COMMON_OCPM:
1392 		dev_dbg(hub_dev, "global over-current protection\n");
1393 		break;
1394 	case HUB_CHAR_INDV_PORT_OCPM:
1395 		dev_dbg(hub_dev, "individual port over-current protection\n");
1396 		break;
1397 	case HUB_CHAR_NO_OCPM:
1398 	case HUB_CHAR_OCPM:
1399 		dev_dbg(hub_dev, "no over-current protection\n");
1400 		break;
1401 	}
1402 
1403 	spin_lock_init (&hub->tt.lock);
1404 	INIT_LIST_HEAD (&hub->tt.clear_list);
1405 	INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1406 	switch (hdev->descriptor.bDeviceProtocol) {
1407 	case USB_HUB_PR_FS:
1408 		break;
1409 	case USB_HUB_PR_HS_SINGLE_TT:
1410 		dev_dbg(hub_dev, "Single TT\n");
1411 		hub->tt.hub = hdev;
1412 		break;
1413 	case USB_HUB_PR_HS_MULTI_TT:
1414 		ret = usb_set_interface(hdev, 0, 1);
1415 		if (ret == 0) {
1416 			dev_dbg(hub_dev, "TT per port\n");
1417 			hub->tt.multi = 1;
1418 		} else
1419 			dev_err(hub_dev, "Using single TT (err %d)\n",
1420 				ret);
1421 		hub->tt.hub = hdev;
1422 		break;
1423 	case USB_HUB_PR_SS:
1424 		/* USB 3.0 hubs don't have a TT */
1425 		break;
1426 	default:
1427 		dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1428 			hdev->descriptor.bDeviceProtocol);
1429 		break;
1430 	}
1431 
1432 	/* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1433 	switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1434 		case HUB_TTTT_8_BITS:
1435 			if (hdev->descriptor.bDeviceProtocol != 0) {
1436 				hub->tt.think_time = 666;
1437 				dev_dbg(hub_dev, "TT requires at most %d "
1438 						"FS bit times (%d ns)\n",
1439 					8, hub->tt.think_time);
1440 			}
1441 			break;
1442 		case HUB_TTTT_16_BITS:
1443 			hub->tt.think_time = 666 * 2;
1444 			dev_dbg(hub_dev, "TT requires at most %d "
1445 					"FS bit times (%d ns)\n",
1446 				16, hub->tt.think_time);
1447 			break;
1448 		case HUB_TTTT_24_BITS:
1449 			hub->tt.think_time = 666 * 3;
1450 			dev_dbg(hub_dev, "TT requires at most %d "
1451 					"FS bit times (%d ns)\n",
1452 				24, hub->tt.think_time);
1453 			break;
1454 		case HUB_TTTT_32_BITS:
1455 			hub->tt.think_time = 666 * 4;
1456 			dev_dbg(hub_dev, "TT requires at most %d "
1457 					"FS bit times (%d ns)\n",
1458 				32, hub->tt.think_time);
1459 			break;
1460 	}
1461 
1462 	/* probe() zeroes hub->indicator[] */
1463 	if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1464 		hub->has_indicators = 1;
1465 		dev_dbg(hub_dev, "Port indicators are supported\n");
1466 	}
1467 
1468 	dev_dbg(hub_dev, "power on to power good time: %dms\n",
1469 		hub->descriptor->bPwrOn2PwrGood * 2);
1470 
1471 	/* power budgeting mostly matters with bus-powered hubs,
1472 	 * and battery-powered root hubs (may provide just 8 mA).
1473 	 */
1474 	ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1475 	if (ret < 2) {
1476 		message = "can't get hub status";
1477 		goto fail;
1478 	}
1479 	le16_to_cpus(&hubstatus);
1480 	hcd = bus_to_hcd(hdev->bus);
1481 	if (hdev == hdev->bus->root_hub) {
1482 		if (hcd->power_budget > 0)
1483 			hdev->bus_mA = hcd->power_budget;
1484 		else
1485 			hdev->bus_mA = full_load * hdev->maxchild;
1486 		if (hdev->bus_mA >= full_load)
1487 			hub->mA_per_port = full_load;
1488 		else {
1489 			hub->mA_per_port = hdev->bus_mA;
1490 			hub->limited_power = 1;
1491 		}
1492 	} else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1493 		int remaining = hdev->bus_mA -
1494 			hub->descriptor->bHubContrCurrent;
1495 
1496 		dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1497 			hub->descriptor->bHubContrCurrent);
1498 		hub->limited_power = 1;
1499 
1500 		if (remaining < hdev->maxchild * unit_load)
1501 			dev_warn(hub_dev,
1502 					"insufficient power available "
1503 					"to use all downstream ports\n");
1504 		hub->mA_per_port = unit_load;	/* 7.2.1 */
1505 
1506 	} else {	/* Self-powered external hub */
1507 		/* FIXME: What about battery-powered external hubs that
1508 		 * provide less current per port? */
1509 		hub->mA_per_port = full_load;
1510 	}
1511 	if (hub->mA_per_port < full_load)
1512 		dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1513 				hub->mA_per_port);
1514 
1515 	/* Update the HCD's internal representation of this hub before khubd
1516 	 * starts getting port status changes for devices under the hub.
1517 	 */
1518 	if (hcd->driver->update_hub_device) {
1519 		ret = hcd->driver->update_hub_device(hcd, hdev,
1520 				&hub->tt, GFP_KERNEL);
1521 		if (ret < 0) {
1522 			message = "can't update HCD hub info";
1523 			goto fail;
1524 		}
1525 	}
1526 
1527 	ret = hub_hub_status(hub, &hubstatus, &hubchange);
1528 	if (ret < 0) {
1529 		message = "can't get hub status";
1530 		goto fail;
1531 	}
1532 
1533 	/* local power status reports aren't always correct */
1534 	if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1535 		dev_dbg(hub_dev, "local power source is %s\n",
1536 			(hubstatus & HUB_STATUS_LOCAL_POWER)
1537 			? "lost (inactive)" : "good");
1538 
1539 	if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1540 		dev_dbg(hub_dev, "%sover-current condition exists\n",
1541 			(hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1542 
1543 	/* set up the interrupt endpoint
1544 	 * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1545 	 * bytes as USB2.0[11.12.3] says because some hubs are known
1546 	 * to send more data (and thus cause overflow). For root hubs,
1547 	 * maxpktsize is defined in hcd.c's fake endpoint descriptors
1548 	 * to be big enough for at least USB_MAXCHILDREN ports. */
1549 	pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1550 	maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
1551 
1552 	if (maxp > sizeof(*hub->buffer))
1553 		maxp = sizeof(*hub->buffer);
1554 
1555 	hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1556 	if (!hub->urb) {
1557 		ret = -ENOMEM;
1558 		goto fail;
1559 	}
1560 
1561 	usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1562 		hub, endpoint->bInterval);
1563 
1564 	/* maybe cycle the hub leds */
1565 	if (hub->has_indicators && blinkenlights)
1566 		hub->indicator [0] = INDICATOR_CYCLE;
1567 
1568 	for (i = 0; i < hdev->maxchild; i++)
1569 		if (usb_hub_create_port_device(hub, i + 1) < 0)
1570 			dev_err(hub->intfdev,
1571 				"couldn't create port%d device.\n", i + 1);
1572 
1573 	usb_hub_adjust_deviceremovable(hdev, hub->descriptor);
1574 
1575 	hub_activate(hub, HUB_INIT);
1576 	return 0;
1577 
1578 fail:
1579 	dev_err (hub_dev, "config failed, %s (err %d)\n",
1580 			message, ret);
1581 	/* hub_disconnect() frees urb and descriptor */
1582 	return ret;
1583 }
1584 
hub_release(struct kref * kref)1585 static void hub_release(struct kref *kref)
1586 {
1587 	struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1588 
1589 	usb_put_intf(to_usb_interface(hub->intfdev));
1590 	kfree(hub);
1591 }
1592 
1593 static unsigned highspeed_hubs;
1594 
hub_disconnect(struct usb_interface * intf)1595 static void hub_disconnect(struct usb_interface *intf)
1596 {
1597 	struct usb_hub *hub = usb_get_intfdata(intf);
1598 	struct usb_device *hdev = interface_to_usbdev(intf);
1599 	int i;
1600 
1601 	/* Take the hub off the event list and don't let it be added again */
1602 	spin_lock_irq(&hub_event_lock);
1603 	if (!list_empty(&hub->event_list)) {
1604 		list_del_init(&hub->event_list);
1605 		usb_autopm_put_interface_no_suspend(intf);
1606 	}
1607 	hub->disconnected = 1;
1608 	spin_unlock_irq(&hub_event_lock);
1609 
1610 	/* Disconnect all children and quiesce the hub */
1611 	hub->error = 0;
1612 	hub_quiesce(hub, HUB_DISCONNECT);
1613 
1614 	usb_set_intfdata (intf, NULL);
1615 
1616 	for (i = 0; i < hdev->maxchild; i++)
1617 		usb_hub_remove_port_device(hub, i + 1);
1618 	hub->hdev->maxchild = 0;
1619 
1620 	if (hub->hdev->speed == USB_SPEED_HIGH)
1621 		highspeed_hubs--;
1622 
1623 	usb_free_urb(hub->urb);
1624 	kfree(hub->ports);
1625 	kfree(hub->descriptor);
1626 	kfree(hub->status);
1627 	kfree(hub->buffer);
1628 
1629 	pm_suspend_ignore_children(&intf->dev, false);
1630 	kref_put(&hub->kref, hub_release);
1631 }
1632 
hub_probe(struct usb_interface * intf,const struct usb_device_id * id)1633 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1634 {
1635 	struct usb_host_interface *desc;
1636 	struct usb_endpoint_descriptor *endpoint;
1637 	struct usb_device *hdev;
1638 	struct usb_hub *hub;
1639 
1640 	desc = intf->cur_altsetting;
1641 	hdev = interface_to_usbdev(intf);
1642 
1643 	/*
1644 	 * Set default autosuspend delay as 0 to speedup bus suspend,
1645 	 * based on the below considerations:
1646 	 *
1647 	 * - Unlike other drivers, the hub driver does not rely on the
1648 	 *   autosuspend delay to provide enough time to handle a wakeup
1649 	 *   event, and the submitted status URB is just to check future
1650 	 *   change on hub downstream ports, so it is safe to do it.
1651 	 *
1652 	 * - The patch might cause one or more auto supend/resume for
1653 	 *   below very rare devices when they are plugged into hub
1654 	 *   first time:
1655 	 *
1656 	 *   	devices having trouble initializing, and disconnect
1657 	 *   	themselves from the bus and then reconnect a second
1658 	 *   	or so later
1659 	 *
1660 	 *   	devices just for downloading firmware, and disconnects
1661 	 *   	themselves after completing it
1662 	 *
1663 	 *   For these quite rare devices, their drivers may change the
1664 	 *   autosuspend delay of their parent hub in the probe() to one
1665 	 *   appropriate value to avoid the subtle problem if someone
1666 	 *   does care it.
1667 	 *
1668 	 * - The patch may cause one or more auto suspend/resume on
1669 	 *   hub during running 'lsusb', but it is probably too
1670 	 *   infrequent to worry about.
1671 	 *
1672 	 * - Change autosuspend delay of hub can avoid unnecessary auto
1673 	 *   suspend timer for hub, also may decrease power consumption
1674 	 *   of USB bus.
1675 	 */
1676 	pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
1677 
1678 	/* Hubs have proper suspend/resume support. */
1679 	usb_enable_autosuspend(hdev);
1680 
1681 	if (hdev->level == MAX_TOPO_LEVEL) {
1682 		dev_err(&intf->dev,
1683 			"Unsupported bus topology: hub nested too deep\n");
1684 		return -E2BIG;
1685 	}
1686 
1687 #ifdef	CONFIG_USB_OTG_BLACKLIST_HUB
1688 	if (hdev->parent) {
1689 		dev_warn(&intf->dev, "ignoring external hub\n");
1690 		return -ENODEV;
1691 	}
1692 #endif
1693 
1694 	/* Some hubs have a subclass of 1, which AFAICT according to the */
1695 	/*  specs is not defined, but it works */
1696 	if ((desc->desc.bInterfaceSubClass != 0) &&
1697 	    (desc->desc.bInterfaceSubClass != 1)) {
1698 descriptor_error:
1699 		dev_err (&intf->dev, "bad descriptor, ignoring hub\n");
1700 		return -EIO;
1701 	}
1702 
1703 	/* Multiple endpoints? What kind of mutant ninja-hub is this? */
1704 	if (desc->desc.bNumEndpoints != 1)
1705 		goto descriptor_error;
1706 
1707 	endpoint = &desc->endpoint[0].desc;
1708 
1709 	/* If it's not an interrupt in endpoint, we'd better punt! */
1710 	if (!usb_endpoint_is_int_in(endpoint))
1711 		goto descriptor_error;
1712 
1713 	/* We found a hub */
1714 	dev_info (&intf->dev, "USB hub found\n");
1715 
1716 	hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1717 	if (!hub) {
1718 		dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n");
1719 		return -ENOMEM;
1720 	}
1721 
1722 	kref_init(&hub->kref);
1723 	INIT_LIST_HEAD(&hub->event_list);
1724 	hub->intfdev = &intf->dev;
1725 	hub->hdev = hdev;
1726 	INIT_DELAYED_WORK(&hub->leds, led_work);
1727 	INIT_DELAYED_WORK(&hub->init_work, NULL);
1728 	usb_get_intf(intf);
1729 
1730 	usb_set_intfdata (intf, hub);
1731 	intf->needs_remote_wakeup = 1;
1732 	pm_suspend_ignore_children(&intf->dev, true);
1733 
1734 	if (hdev->speed == USB_SPEED_HIGH)
1735 		highspeed_hubs++;
1736 
1737 	if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
1738 		hub->quirk_check_port_auto_suspend = 1;
1739 
1740 	if (hub_configure(hub, endpoint) >= 0)
1741 		return 0;
1742 
1743 	hub_disconnect (intf);
1744 	return -ENODEV;
1745 }
1746 
1747 static int
hub_ioctl(struct usb_interface * intf,unsigned int code,void * user_data)1748 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1749 {
1750 	struct usb_device *hdev = interface_to_usbdev (intf);
1751 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1752 
1753 	/* assert ifno == 0 (part of hub spec) */
1754 	switch (code) {
1755 	case USBDEVFS_HUB_PORTINFO: {
1756 		struct usbdevfs_hub_portinfo *info = user_data;
1757 		int i;
1758 
1759 		spin_lock_irq(&device_state_lock);
1760 		if (hdev->devnum <= 0)
1761 			info->nports = 0;
1762 		else {
1763 			info->nports = hdev->maxchild;
1764 			for (i = 0; i < info->nports; i++) {
1765 				if (hub->ports[i]->child == NULL)
1766 					info->port[i] = 0;
1767 				else
1768 					info->port[i] =
1769 						hub->ports[i]->child->devnum;
1770 			}
1771 		}
1772 		spin_unlock_irq(&device_state_lock);
1773 
1774 		return info->nports + 1;
1775 		}
1776 
1777 	default:
1778 		return -ENOSYS;
1779 	}
1780 }
1781 
1782 /*
1783  * Allow user programs to claim ports on a hub.  When a device is attached
1784  * to one of these "claimed" ports, the program will "own" the device.
1785  */
find_port_owner(struct usb_device * hdev,unsigned port1,struct dev_state *** ppowner)1786 static int find_port_owner(struct usb_device *hdev, unsigned port1,
1787 		struct dev_state ***ppowner)
1788 {
1789 	if (hdev->state == USB_STATE_NOTATTACHED)
1790 		return -ENODEV;
1791 	if (port1 == 0 || port1 > hdev->maxchild)
1792 		return -EINVAL;
1793 
1794 	/* This assumes that devices not managed by the hub driver
1795 	 * will always have maxchild equal to 0.
1796 	 */
1797 	*ppowner = &(usb_hub_to_struct_hub(hdev)->ports[port1 - 1]->port_owner);
1798 	return 0;
1799 }
1800 
1801 /* In the following three functions, the caller must hold hdev's lock */
usb_hub_claim_port(struct usb_device * hdev,unsigned port1,struct dev_state * owner)1802 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
1803 		       struct dev_state *owner)
1804 {
1805 	int rc;
1806 	struct dev_state **powner;
1807 
1808 	rc = find_port_owner(hdev, port1, &powner);
1809 	if (rc)
1810 		return rc;
1811 	if (*powner)
1812 		return -EBUSY;
1813 	*powner = owner;
1814 	return rc;
1815 }
1816 
usb_hub_release_port(struct usb_device * hdev,unsigned port1,struct dev_state * owner)1817 int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
1818 			 struct dev_state *owner)
1819 {
1820 	int rc;
1821 	struct dev_state **powner;
1822 
1823 	rc = find_port_owner(hdev, port1, &powner);
1824 	if (rc)
1825 		return rc;
1826 	if (*powner != owner)
1827 		return -ENOENT;
1828 	*powner = NULL;
1829 	return rc;
1830 }
1831 
usb_hub_release_all_ports(struct usb_device * hdev,struct dev_state * owner)1832 void usb_hub_release_all_ports(struct usb_device *hdev, struct dev_state *owner)
1833 {
1834 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1835 	int n;
1836 
1837 	for (n = 0; n < hdev->maxchild; n++) {
1838 		if (hub->ports[n]->port_owner == owner)
1839 			hub->ports[n]->port_owner = NULL;
1840 	}
1841 
1842 }
1843 
1844 /* The caller must hold udev's lock */
usb_device_is_owned(struct usb_device * udev)1845 bool usb_device_is_owned(struct usb_device *udev)
1846 {
1847 	struct usb_hub *hub;
1848 
1849 	if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
1850 		return false;
1851 	hub = usb_hub_to_struct_hub(udev->parent);
1852 	return !!hub->ports[udev->portnum - 1]->port_owner;
1853 }
1854 
recursively_mark_NOTATTACHED(struct usb_device * udev)1855 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1856 {
1857 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
1858 	int i;
1859 
1860 	for (i = 0; i < udev->maxchild; ++i) {
1861 		if (hub->ports[i]->child)
1862 			recursively_mark_NOTATTACHED(hub->ports[i]->child);
1863 	}
1864 	if (udev->state == USB_STATE_SUSPENDED)
1865 		udev->active_duration -= jiffies;
1866 	udev->state = USB_STATE_NOTATTACHED;
1867 }
1868 
1869 /**
1870  * usb_set_device_state - change a device's current state (usbcore, hcds)
1871  * @udev: pointer to device whose state should be changed
1872  * @new_state: new state value to be stored
1873  *
1874  * udev->state is _not_ fully protected by the device lock.  Although
1875  * most transitions are made only while holding the lock, the state can
1876  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1877  * is so that devices can be marked as disconnected as soon as possible,
1878  * without having to wait for any semaphores to be released.  As a result,
1879  * all changes to any device's state must be protected by the
1880  * device_state_lock spinlock.
1881  *
1882  * Once a device has been added to the device tree, all changes to its state
1883  * should be made using this routine.  The state should _not_ be set directly.
1884  *
1885  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1886  * Otherwise udev->state is set to new_state, and if new_state is
1887  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1888  * to USB_STATE_NOTATTACHED.
1889  */
usb_set_device_state(struct usb_device * udev,enum usb_device_state new_state)1890 void usb_set_device_state(struct usb_device *udev,
1891 		enum usb_device_state new_state)
1892 {
1893 	unsigned long flags;
1894 	int wakeup = -1;
1895 
1896 	spin_lock_irqsave(&device_state_lock, flags);
1897 	if (udev->state == USB_STATE_NOTATTACHED)
1898 		;	/* do nothing */
1899 	else if (new_state != USB_STATE_NOTATTACHED) {
1900 
1901 		/* root hub wakeup capabilities are managed out-of-band
1902 		 * and may involve silicon errata ... ignore them here.
1903 		 */
1904 		if (udev->parent) {
1905 			if (udev->state == USB_STATE_SUSPENDED
1906 					|| new_state == USB_STATE_SUSPENDED)
1907 				;	/* No change to wakeup settings */
1908 			else if (new_state == USB_STATE_CONFIGURED)
1909 				wakeup = udev->actconfig->desc.bmAttributes
1910 					 & USB_CONFIG_ATT_WAKEUP;
1911 			else
1912 				wakeup = 0;
1913 		}
1914 		if (udev->state == USB_STATE_SUSPENDED &&
1915 			new_state != USB_STATE_SUSPENDED)
1916 			udev->active_duration -= jiffies;
1917 		else if (new_state == USB_STATE_SUSPENDED &&
1918 				udev->state != USB_STATE_SUSPENDED)
1919 			udev->active_duration += jiffies;
1920 		udev->state = new_state;
1921 	} else
1922 		recursively_mark_NOTATTACHED(udev);
1923 	spin_unlock_irqrestore(&device_state_lock, flags);
1924 	if (wakeup >= 0)
1925 		device_set_wakeup_capable(&udev->dev, wakeup);
1926 }
1927 EXPORT_SYMBOL_GPL(usb_set_device_state);
1928 
1929 /*
1930  * Choose a device number.
1931  *
1932  * Device numbers are used as filenames in usbfs.  On USB-1.1 and
1933  * USB-2.0 buses they are also used as device addresses, however on
1934  * USB-3.0 buses the address is assigned by the controller hardware
1935  * and it usually is not the same as the device number.
1936  *
1937  * WUSB devices are simple: they have no hubs behind, so the mapping
1938  * device <-> virtual port number becomes 1:1. Why? to simplify the
1939  * life of the device connection logic in
1940  * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
1941  * handshake we need to assign a temporary address in the unauthorized
1942  * space. For simplicity we use the first virtual port number found to
1943  * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
1944  * and that becomes it's address [X < 128] or its unauthorized address
1945  * [X | 0x80].
1946  *
1947  * We add 1 as an offset to the one-based USB-stack port number
1948  * (zero-based wusb virtual port index) for two reasons: (a) dev addr
1949  * 0 is reserved by USB for default address; (b) Linux's USB stack
1950  * uses always #1 for the root hub of the controller. So USB stack's
1951  * port #1, which is wusb virtual-port #0 has address #2.
1952  *
1953  * Devices connected under xHCI are not as simple.  The host controller
1954  * supports virtualization, so the hardware assigns device addresses and
1955  * the HCD must setup data structures before issuing a set address
1956  * command to the hardware.
1957  */
choose_devnum(struct usb_device * udev)1958 static void choose_devnum(struct usb_device *udev)
1959 {
1960 	int		devnum;
1961 	struct usb_bus	*bus = udev->bus;
1962 
1963 	/* If khubd ever becomes multithreaded, this will need a lock */
1964 	if (udev->wusb) {
1965 		devnum = udev->portnum + 1;
1966 		BUG_ON(test_bit(devnum, bus->devmap.devicemap));
1967 	} else {
1968 		/* Try to allocate the next devnum beginning at
1969 		 * bus->devnum_next. */
1970 		devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
1971 					    bus->devnum_next);
1972 		if (devnum >= 128)
1973 			devnum = find_next_zero_bit(bus->devmap.devicemap,
1974 						    128, 1);
1975 		bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1);
1976 	}
1977 	if (devnum < 128) {
1978 		set_bit(devnum, bus->devmap.devicemap);
1979 		udev->devnum = devnum;
1980 	}
1981 }
1982 
release_devnum(struct usb_device * udev)1983 static void release_devnum(struct usb_device *udev)
1984 {
1985 	if (udev->devnum > 0) {
1986 		clear_bit(udev->devnum, udev->bus->devmap.devicemap);
1987 		udev->devnum = -1;
1988 	}
1989 }
1990 
update_devnum(struct usb_device * udev,int devnum)1991 static void update_devnum(struct usb_device *udev, int devnum)
1992 {
1993 	/* The address for a WUSB device is managed by wusbcore. */
1994 	if (!udev->wusb)
1995 		udev->devnum = devnum;
1996 }
1997 
hub_free_dev(struct usb_device * udev)1998 static void hub_free_dev(struct usb_device *udev)
1999 {
2000 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2001 
2002 	/* Root hubs aren't real devices, so don't free HCD resources */
2003 	if (hcd->driver->free_dev && udev->parent)
2004 		hcd->driver->free_dev(hcd, udev);
2005 }
2006 
2007 /**
2008  * usb_disconnect - disconnect a device (usbcore-internal)
2009  * @pdev: pointer to device being disconnected
2010  * Context: !in_interrupt ()
2011  *
2012  * Something got disconnected. Get rid of it and all of its children.
2013  *
2014  * If *pdev is a normal device then the parent hub must already be locked.
2015  * If *pdev is a root hub then this routine will acquire the
2016  * usb_bus_list_lock on behalf of the caller.
2017  *
2018  * Only hub drivers (including virtual root hub drivers for host
2019  * controllers) should ever call this.
2020  *
2021  * This call is synchronous, and may not be used in an interrupt context.
2022  */
usb_disconnect(struct usb_device ** pdev)2023 void usb_disconnect(struct usb_device **pdev)
2024 {
2025 	struct usb_device	*udev = *pdev;
2026 	struct usb_hub		*hub = usb_hub_to_struct_hub(udev);
2027 	int			i;
2028 
2029 	/* mark the device as inactive, so any further urb submissions for
2030 	 * this device (and any of its children) will fail immediately.
2031 	 * this quiesces everything except pending urbs.
2032 	 */
2033 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2034 	dev_info(&udev->dev, "USB disconnect, device number %d\n",
2035 			udev->devnum);
2036 
2037 	usb_lock_device(udev);
2038 
2039 	/* Free up all the children before we remove this device */
2040 	for (i = 0; i < udev->maxchild; i++) {
2041 		if (hub->ports[i]->child)
2042 			usb_disconnect(&hub->ports[i]->child);
2043 	}
2044 
2045 	/* deallocate hcd/hardware state ... nuking all pending urbs and
2046 	 * cleaning up all state associated with the current configuration
2047 	 * so that the hardware is now fully quiesced.
2048 	 */
2049 	dev_dbg (&udev->dev, "unregistering device\n");
2050 	usb_disable_device(udev, 0);
2051 	usb_hcd_synchronize_unlinks(udev);
2052 
2053 	if (udev->parent) {
2054 		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
2055 		struct usb_port	*port_dev = hub->ports[udev->portnum - 1];
2056 
2057 		sysfs_remove_link(&udev->dev.kobj, "port");
2058 		sysfs_remove_link(&port_dev->dev.kobj, "device");
2059 
2060 		if (!port_dev->did_runtime_put)
2061 			pm_runtime_put(&port_dev->dev);
2062 		else
2063 			port_dev->did_runtime_put = false;
2064 	}
2065 
2066 	usb_remove_ep_devs(&udev->ep0);
2067 	usb_unlock_device(udev);
2068 
2069 	/* Unregister the device.  The device driver is responsible
2070 	 * for de-configuring the device and invoking the remove-device
2071 	 * notifier chain (used by usbfs and possibly others).
2072 	 */
2073 	device_del(&udev->dev);
2074 
2075 	/* Free the device number and delete the parent's children[]
2076 	 * (or root_hub) pointer.
2077 	 */
2078 	release_devnum(udev);
2079 
2080 	/* Avoid races with recursively_mark_NOTATTACHED() */
2081 	spin_lock_irq(&device_state_lock);
2082 	*pdev = NULL;
2083 	spin_unlock_irq(&device_state_lock);
2084 
2085 	hub_free_dev(udev);
2086 
2087 	put_device(&udev->dev);
2088 }
2089 
2090 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
show_string(struct usb_device * udev,char * id,char * string)2091 static void show_string(struct usb_device *udev, char *id, char *string)
2092 {
2093 	if (!string)
2094 		return;
2095 	dev_info(&udev->dev, "%s: %s\n", id, string);
2096 }
2097 
announce_device(struct usb_device * udev)2098 static void announce_device(struct usb_device *udev)
2099 {
2100 	dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
2101 		le16_to_cpu(udev->descriptor.idVendor),
2102 		le16_to_cpu(udev->descriptor.idProduct));
2103 	dev_info(&udev->dev,
2104 		"New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
2105 		udev->descriptor.iManufacturer,
2106 		udev->descriptor.iProduct,
2107 		udev->descriptor.iSerialNumber);
2108 	show_string(udev, "Product", udev->product);
2109 	show_string(udev, "Manufacturer", udev->manufacturer);
2110 	show_string(udev, "SerialNumber", udev->serial);
2111 }
2112 #else
announce_device(struct usb_device * udev)2113 static inline void announce_device(struct usb_device *udev) { }
2114 #endif
2115 
2116 #ifdef	CONFIG_USB_OTG
2117 #include "otg_whitelist.h"
2118 #endif
2119 
2120 /**
2121  * usb_enumerate_device_otg - FIXME (usbcore-internal)
2122  * @udev: newly addressed device (in ADDRESS state)
2123  *
2124  * Finish enumeration for On-The-Go devices
2125  */
usb_enumerate_device_otg(struct usb_device * udev)2126 static int usb_enumerate_device_otg(struct usb_device *udev)
2127 {
2128 	int err = 0;
2129 
2130 #ifdef	CONFIG_USB_OTG
2131 	/*
2132 	 * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
2133 	 * to wake us after we've powered off VBUS; and HNP, switching roles
2134 	 * "host" to "peripheral".  The OTG descriptor helps figure this out.
2135 	 */
2136 	if (!udev->bus->is_b_host
2137 			&& udev->config
2138 			&& udev->parent == udev->bus->root_hub) {
2139 		struct usb_otg_descriptor	*desc = NULL;
2140 		struct usb_bus			*bus = udev->bus;
2141 
2142 		/* descriptor may appear anywhere in config */
2143 		if (__usb_get_extra_descriptor (udev->rawdescriptors[0],
2144 					le16_to_cpu(udev->config[0].desc.wTotalLength),
2145 					USB_DT_OTG, (void **) &desc) == 0) {
2146 			if (desc->bmAttributes & USB_OTG_HNP) {
2147 				unsigned		port1 = udev->portnum;
2148 
2149 				dev_info(&udev->dev,
2150 					"Dual-Role OTG device on %sHNP port\n",
2151 					(port1 == bus->otg_port)
2152 						? "" : "non-");
2153 
2154 				/* enable HNP before suspend, it's simpler */
2155 				if (port1 == bus->otg_port)
2156 					bus->b_hnp_enable = 1;
2157 				err = usb_control_msg(udev,
2158 					usb_sndctrlpipe(udev, 0),
2159 					USB_REQ_SET_FEATURE, 0,
2160 					bus->b_hnp_enable
2161 						? USB_DEVICE_B_HNP_ENABLE
2162 						: USB_DEVICE_A_ALT_HNP_SUPPORT,
2163 					0, NULL, 0, USB_CTRL_SET_TIMEOUT);
2164 				if (err < 0) {
2165 					/* OTG MESSAGE: report errors here,
2166 					 * customize to match your product.
2167 					 */
2168 					dev_info(&udev->dev,
2169 						"can't set HNP mode: %d\n",
2170 						err);
2171 					bus->b_hnp_enable = 0;
2172 				}
2173 			}
2174 		}
2175 	}
2176 
2177 	if (!is_targeted(udev)) {
2178 
2179 		/* Maybe it can talk to us, though we can't talk to it.
2180 		 * (Includes HNP test device.)
2181 		 */
2182 		if (udev->bus->b_hnp_enable || udev->bus->is_b_host) {
2183 			err = usb_port_suspend(udev, PMSG_SUSPEND);
2184 			if (err < 0)
2185 				dev_dbg(&udev->dev, "HNP fail, %d\n", err);
2186 		}
2187 		err = -ENOTSUPP;
2188 		goto fail;
2189 	}
2190 fail:
2191 #endif
2192 	return err;
2193 }
2194 
2195 
2196 /**
2197  * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
2198  * @udev: newly addressed device (in ADDRESS state)
2199  *
2200  * This is only called by usb_new_device() and usb_authorize_device()
2201  * and FIXME -- all comments that apply to them apply here wrt to
2202  * environment.
2203  *
2204  * If the device is WUSB and not authorized, we don't attempt to read
2205  * the string descriptors, as they will be errored out by the device
2206  * until it has been authorized.
2207  */
usb_enumerate_device(struct usb_device * udev)2208 static int usb_enumerate_device(struct usb_device *udev)
2209 {
2210 	int err;
2211 
2212 	if (udev->config == NULL) {
2213 		err = usb_get_configuration(udev);
2214 		if (err < 0) {
2215 			if (err != -ENODEV)
2216 				dev_err(&udev->dev, "can't read configurations, error %d\n",
2217 						err);
2218 			return err;
2219 		}
2220 	}
2221 	if (udev->wusb == 1 && udev->authorized == 0) {
2222 		udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2223 		udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2224 		udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2225 	}
2226 	else {
2227 		/* read the standard strings and cache them if present */
2228 		udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
2229 		udev->manufacturer = usb_cache_string(udev,
2230 						      udev->descriptor.iManufacturer);
2231 		udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
2232 	}
2233 	err = usb_enumerate_device_otg(udev);
2234 	if (err < 0)
2235 		return err;
2236 
2237 	usb_detect_interface_quirks(udev);
2238 
2239 	return 0;
2240 }
2241 
set_usb_port_removable(struct usb_device * udev)2242 static void set_usb_port_removable(struct usb_device *udev)
2243 {
2244 	struct usb_device *hdev = udev->parent;
2245 	struct usb_hub *hub;
2246 	u8 port = udev->portnum;
2247 	u16 wHubCharacteristics;
2248 	bool removable = true;
2249 
2250 	if (!hdev)
2251 		return;
2252 
2253 	hub = usb_hub_to_struct_hub(udev->parent);
2254 
2255 	wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2256 
2257 	if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
2258 		return;
2259 
2260 	if (hub_is_superspeed(hdev)) {
2261 		if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
2262 				& (1 << port))
2263 			removable = false;
2264 	} else {
2265 		if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
2266 			removable = false;
2267 	}
2268 
2269 	if (removable)
2270 		udev->removable = USB_DEVICE_REMOVABLE;
2271 	else
2272 		udev->removable = USB_DEVICE_FIXED;
2273 }
2274 
2275 /**
2276  * usb_new_device - perform initial device setup (usbcore-internal)
2277  * @udev: newly addressed device (in ADDRESS state)
2278  *
2279  * This is called with devices which have been detected but not fully
2280  * enumerated.  The device descriptor is available, but not descriptors
2281  * for any device configuration.  The caller must have locked either
2282  * the parent hub (if udev is a normal device) or else the
2283  * usb_bus_list_lock (if udev is a root hub).  The parent's pointer to
2284  * udev has already been installed, but udev is not yet visible through
2285  * sysfs or other filesystem code.
2286  *
2287  * It will return if the device is configured properly or not.  Zero if
2288  * the interface was registered with the driver core; else a negative
2289  * errno value.
2290  *
2291  * This call is synchronous, and may not be used in an interrupt context.
2292  *
2293  * Only the hub driver or root-hub registrar should ever call this.
2294  */
usb_new_device(struct usb_device * udev)2295 int usb_new_device(struct usb_device *udev)
2296 {
2297 	int err;
2298 
2299 	if (udev->parent) {
2300 		/* Initialize non-root-hub device wakeup to disabled;
2301 		 * device (un)configuration controls wakeup capable
2302 		 * sysfs power/wakeup controls wakeup enabled/disabled
2303 		 */
2304 		device_init_wakeup(&udev->dev, 0);
2305 	}
2306 
2307 	/* Tell the runtime-PM framework the device is active */
2308 	pm_runtime_set_active(&udev->dev);
2309 	pm_runtime_get_noresume(&udev->dev);
2310 	pm_runtime_use_autosuspend(&udev->dev);
2311 	pm_runtime_enable(&udev->dev);
2312 
2313 	/* By default, forbid autosuspend for all devices.  It will be
2314 	 * allowed for hubs during binding.
2315 	 */
2316 	usb_disable_autosuspend(udev);
2317 
2318 	err = usb_enumerate_device(udev);	/* Read descriptors */
2319 	if (err < 0)
2320 		goto fail;
2321 	dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
2322 			udev->devnum, udev->bus->busnum,
2323 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2324 	/* export the usbdev device-node for libusb */
2325 	udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
2326 			(((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2327 
2328 	/* Tell the world! */
2329 	announce_device(udev);
2330 
2331 	if (udev->serial)
2332 		add_device_randomness(udev->serial, strlen(udev->serial));
2333 	if (udev->product)
2334 		add_device_randomness(udev->product, strlen(udev->product));
2335 	if (udev->manufacturer)
2336 		add_device_randomness(udev->manufacturer,
2337 				      strlen(udev->manufacturer));
2338 
2339 	device_enable_async_suspend(&udev->dev);
2340 
2341 	/*
2342 	 * check whether the hub marks this port as non-removable. Do it
2343 	 * now so that platform-specific data can override it in
2344 	 * device_add()
2345 	 */
2346 	if (udev->parent)
2347 		set_usb_port_removable(udev);
2348 
2349 	/* Register the device.  The device driver is responsible
2350 	 * for configuring the device and invoking the add-device
2351 	 * notifier chain (used by usbfs and possibly others).
2352 	 */
2353 	err = device_add(&udev->dev);
2354 	if (err) {
2355 		dev_err(&udev->dev, "can't device_add, error %d\n", err);
2356 		goto fail;
2357 	}
2358 
2359 	/* Create link files between child device and usb port device. */
2360 	if (udev->parent) {
2361 		struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
2362 		struct usb_port	*port_dev = hub->ports[udev->portnum - 1];
2363 
2364 		err = sysfs_create_link(&udev->dev.kobj,
2365 				&port_dev->dev.kobj, "port");
2366 		if (err)
2367 			goto fail;
2368 
2369 		err = sysfs_create_link(&port_dev->dev.kobj,
2370 				&udev->dev.kobj, "device");
2371 		if (err) {
2372 			sysfs_remove_link(&udev->dev.kobj, "port");
2373 			goto fail;
2374 		}
2375 
2376 		pm_runtime_get_sync(&port_dev->dev);
2377 	}
2378 
2379 	(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
2380 	usb_mark_last_busy(udev);
2381 	pm_runtime_put_sync_autosuspend(&udev->dev);
2382 	return err;
2383 
2384 fail:
2385 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2386 	pm_runtime_disable(&udev->dev);
2387 	pm_runtime_set_suspended(&udev->dev);
2388 	return err;
2389 }
2390 
2391 
2392 /**
2393  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
2394  * @usb_dev: USB device
2395  *
2396  * Move the USB device to a very basic state where interfaces are disabled
2397  * and the device is in fact unconfigured and unusable.
2398  *
2399  * We share a lock (that we have) with device_del(), so we need to
2400  * defer its call.
2401  */
usb_deauthorize_device(struct usb_device * usb_dev)2402 int usb_deauthorize_device(struct usb_device *usb_dev)
2403 {
2404 	usb_lock_device(usb_dev);
2405 	if (usb_dev->authorized == 0)
2406 		goto out_unauthorized;
2407 
2408 	usb_dev->authorized = 0;
2409 	usb_set_configuration(usb_dev, -1);
2410 
2411 	kfree(usb_dev->product);
2412 	usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2413 	kfree(usb_dev->manufacturer);
2414 	usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2415 	kfree(usb_dev->serial);
2416 	usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL);
2417 
2418 	usb_destroy_configuration(usb_dev);
2419 	usb_dev->descriptor.bNumConfigurations = 0;
2420 
2421 out_unauthorized:
2422 	usb_unlock_device(usb_dev);
2423 	return 0;
2424 }
2425 
2426 
usb_authorize_device(struct usb_device * usb_dev)2427 int usb_authorize_device(struct usb_device *usb_dev)
2428 {
2429 	int result = 0, c;
2430 
2431 	usb_lock_device(usb_dev);
2432 	if (usb_dev->authorized == 1)
2433 		goto out_authorized;
2434 
2435 	result = usb_autoresume_device(usb_dev);
2436 	if (result < 0) {
2437 		dev_err(&usb_dev->dev,
2438 			"can't autoresume for authorization: %d\n", result);
2439 		goto error_autoresume;
2440 	}
2441 	result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
2442 	if (result < 0) {
2443 		dev_err(&usb_dev->dev, "can't re-read device descriptor for "
2444 			"authorization: %d\n", result);
2445 		goto error_device_descriptor;
2446 	}
2447 
2448 	kfree(usb_dev->product);
2449 	usb_dev->product = NULL;
2450 	kfree(usb_dev->manufacturer);
2451 	usb_dev->manufacturer = NULL;
2452 	kfree(usb_dev->serial);
2453 	usb_dev->serial = NULL;
2454 
2455 	usb_dev->authorized = 1;
2456 	result = usb_enumerate_device(usb_dev);
2457 	if (result < 0)
2458 		goto error_enumerate;
2459 	/* Choose and set the configuration.  This registers the interfaces
2460 	 * with the driver core and lets interface drivers bind to them.
2461 	 */
2462 	c = usb_choose_configuration(usb_dev);
2463 	if (c >= 0) {
2464 		result = usb_set_configuration(usb_dev, c);
2465 		if (result) {
2466 			dev_err(&usb_dev->dev,
2467 				"can't set config #%d, error %d\n", c, result);
2468 			/* This need not be fatal.  The user can try to
2469 			 * set other configurations. */
2470 		}
2471 	}
2472 	dev_info(&usb_dev->dev, "authorized to connect\n");
2473 
2474 error_enumerate:
2475 error_device_descriptor:
2476 	usb_autosuspend_device(usb_dev);
2477 error_autoresume:
2478 out_authorized:
2479 	usb_unlock_device(usb_dev);	// complements locktree
2480 	return result;
2481 }
2482 
2483 
2484 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
hub_is_wusb(struct usb_hub * hub)2485 static unsigned hub_is_wusb(struct usb_hub *hub)
2486 {
2487 	struct usb_hcd *hcd;
2488 	if (hub->hdev->parent != NULL)  /* not a root hub? */
2489 		return 0;
2490 	hcd = container_of(hub->hdev->bus, struct usb_hcd, self);
2491 	return hcd->wireless;
2492 }
2493 
2494 
2495 #define PORT_RESET_TRIES	5
2496 #define SET_ADDRESS_TRIES	2
2497 #define GET_DESCRIPTOR_TRIES	2
2498 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
2499 #define USE_NEW_SCHEME(i)	((i) / 2 == (int)old_scheme_first)
2500 
2501 #define HUB_ROOT_RESET_TIME	50	/* times are in msec */
2502 #define HUB_SHORT_RESET_TIME	10
2503 #define HUB_BH_RESET_TIME	50
2504 #define HUB_LONG_RESET_TIME	200
2505 #define HUB_RESET_TIMEOUT	800
2506 
2507 static int hub_port_reset(struct usb_hub *hub, int port1,
2508 			struct usb_device *udev, unsigned int delay, bool warm);
2509 
2510 /* Is a USB 3.0 port in the Inactive or Complinance Mode state?
2511  * Port worm reset is required to recover
2512  */
hub_port_warm_reset_required(struct usb_hub * hub,u16 portstatus)2513 static bool hub_port_warm_reset_required(struct usb_hub *hub, u16 portstatus)
2514 {
2515 	return hub_is_superspeed(hub->hdev) &&
2516 		(((portstatus & USB_PORT_STAT_LINK_STATE) ==
2517 		  USB_SS_PORT_LS_SS_INACTIVE) ||
2518 		 ((portstatus & USB_PORT_STAT_LINK_STATE) ==
2519 		  USB_SS_PORT_LS_COMP_MOD)) ;
2520 }
2521 
hub_port_wait_reset(struct usb_hub * hub,int port1,struct usb_device * udev,unsigned int delay,bool warm)2522 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
2523 			struct usb_device *udev, unsigned int delay, bool warm)
2524 {
2525 	int delay_time, ret;
2526 	u16 portstatus;
2527 	u16 portchange;
2528 
2529 	for (delay_time = 0;
2530 			delay_time < HUB_RESET_TIMEOUT;
2531 			delay_time += delay) {
2532 		/* wait to give the device a chance to reset */
2533 		msleep(delay);
2534 
2535 		/* read and decode port status */
2536 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
2537 		if (ret < 0)
2538 			return ret;
2539 
2540 		/* The port state is unknown until the reset completes. */
2541 		if (!(portstatus & USB_PORT_STAT_RESET))
2542 			break;
2543 
2544 		/* switch to the long delay after two short delay failures */
2545 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2546 			delay = HUB_LONG_RESET_TIME;
2547 
2548 		dev_dbg (hub->intfdev,
2549 			"port %d not %sreset yet, waiting %dms\n",
2550 			port1, warm ? "warm " : "", delay);
2551 	}
2552 
2553 	if ((portstatus & USB_PORT_STAT_RESET))
2554 		return -EBUSY;
2555 
2556 	if (hub_port_warm_reset_required(hub, portstatus))
2557 		return -ENOTCONN;
2558 
2559 	/* Device went away? */
2560 	if (!(portstatus & USB_PORT_STAT_CONNECTION))
2561 		return -ENOTCONN;
2562 
2563 	/* bomb out completely if the connection bounced.  A USB 3.0
2564 	 * connection may bounce if multiple warm resets were issued,
2565 	 * but the device may have successfully re-connected. Ignore it.
2566 	 */
2567 	if (!hub_is_superspeed(hub->hdev) &&
2568 			(portchange & USB_PORT_STAT_C_CONNECTION))
2569 		return -ENOTCONN;
2570 
2571 	if (!(portstatus & USB_PORT_STAT_ENABLE))
2572 		return -EBUSY;
2573 
2574 	if (!udev)
2575 		return 0;
2576 
2577 	if (hub_is_wusb(hub))
2578 		udev->speed = USB_SPEED_WIRELESS;
2579 	else if (hub_is_superspeed(hub->hdev))
2580 		udev->speed = USB_SPEED_SUPER;
2581 	else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2582 		udev->speed = USB_SPEED_HIGH;
2583 	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2584 		udev->speed = USB_SPEED_LOW;
2585 	else
2586 		udev->speed = USB_SPEED_FULL;
2587 	return 0;
2588 }
2589 
hub_port_finish_reset(struct usb_hub * hub,int port1,struct usb_device * udev,int * status)2590 static void hub_port_finish_reset(struct usb_hub *hub, int port1,
2591 			struct usb_device *udev, int *status)
2592 {
2593 	switch (*status) {
2594 	case 0:
2595 		/* TRSTRCY = 10 ms; plus some extra */
2596 		msleep(10 + 40);
2597 		if (udev) {
2598 			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2599 
2600 			update_devnum(udev, 0);
2601 			/* The xHC may think the device is already reset,
2602 			 * so ignore the status.
2603 			 */
2604 			if (hcd->driver->reset_device)
2605 				hcd->driver->reset_device(hcd, udev);
2606 		}
2607 		/* FALL THROUGH */
2608 	case -ENOTCONN:
2609 	case -ENODEV:
2610 		usb_clear_port_feature(hub->hdev,
2611 				port1, USB_PORT_FEAT_C_RESET);
2612 		if (hub_is_superspeed(hub->hdev)) {
2613 			usb_clear_port_feature(hub->hdev, port1,
2614 					USB_PORT_FEAT_C_BH_PORT_RESET);
2615 			usb_clear_port_feature(hub->hdev, port1,
2616 					USB_PORT_FEAT_C_PORT_LINK_STATE);
2617 			usb_clear_port_feature(hub->hdev, port1,
2618 					USB_PORT_FEAT_C_CONNECTION);
2619 		}
2620 		if (udev)
2621 			usb_set_device_state(udev, *status
2622 					? USB_STATE_NOTATTACHED
2623 					: USB_STATE_DEFAULT);
2624 		break;
2625 	}
2626 }
2627 
2628 /* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
hub_port_reset(struct usb_hub * hub,int port1,struct usb_device * udev,unsigned int delay,bool warm)2629 static int hub_port_reset(struct usb_hub *hub, int port1,
2630 			struct usb_device *udev, unsigned int delay, bool warm)
2631 {
2632 	int i, status;
2633 	u16 portchange, portstatus;
2634 
2635 	if (!hub_is_superspeed(hub->hdev)) {
2636 		if (warm) {
2637 			dev_err(hub->intfdev, "only USB3 hub support "
2638 						"warm reset\n");
2639 			return -EINVAL;
2640 		}
2641 		/* Block EHCI CF initialization during the port reset.
2642 		 * Some companion controllers don't like it when they mix.
2643 		 */
2644 		down_read(&ehci_cf_port_reset_rwsem);
2645 	} else if (!warm) {
2646 		/*
2647 		 * If the caller hasn't explicitly requested a warm reset,
2648 		 * double check and see if one is needed.
2649 		 */
2650 		status = hub_port_status(hub, port1,
2651 					&portstatus, &portchange);
2652 		if (status < 0)
2653 			goto done;
2654 
2655 		if (hub_port_warm_reset_required(hub, portstatus))
2656 			warm = true;
2657 	}
2658 
2659 	/* Reset the port */
2660 	for (i = 0; i < PORT_RESET_TRIES; i++) {
2661 		status = set_port_feature(hub->hdev, port1, (warm ?
2662 					USB_PORT_FEAT_BH_PORT_RESET :
2663 					USB_PORT_FEAT_RESET));
2664 		if (status == -ENODEV) {
2665 			;	/* The hub is gone */
2666 		} else if (status) {
2667 			dev_err(hub->intfdev,
2668 					"cannot %sreset port %d (err = %d)\n",
2669 					warm ? "warm " : "", port1, status);
2670 		} else {
2671 			status = hub_port_wait_reset(hub, port1, udev, delay,
2672 								warm);
2673 			if (status && status != -ENOTCONN && status != -ENODEV)
2674 				dev_dbg(hub->intfdev,
2675 						"port_wait_reset: err = %d\n",
2676 						status);
2677 		}
2678 
2679 		/* Check for disconnect or reset */
2680 		if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
2681 			hub_port_finish_reset(hub, port1, udev, &status);
2682 
2683 			if (!hub_is_superspeed(hub->hdev))
2684 				goto done;
2685 
2686 			/*
2687 			 * If a USB 3.0 device migrates from reset to an error
2688 			 * state, re-issue the warm reset.
2689 			 */
2690 			if (hub_port_status(hub, port1,
2691 					&portstatus, &portchange) < 0)
2692 				goto done;
2693 
2694 			if (!hub_port_warm_reset_required(hub, portstatus))
2695 				goto done;
2696 
2697 			/*
2698 			 * If the port is in SS.Inactive or Compliance Mode, the
2699 			 * hot or warm reset failed.  Try another warm reset.
2700 			 */
2701 			if (!warm) {
2702 				dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n",
2703 						port1);
2704 				warm = true;
2705 			}
2706 		}
2707 
2708 		dev_dbg (hub->intfdev,
2709 			"port %d not enabled, trying %sreset again...\n",
2710 			port1, warm ? "warm " : "");
2711 		delay = HUB_LONG_RESET_TIME;
2712 	}
2713 
2714 	dev_err (hub->intfdev,
2715 		"Cannot enable port %i.  Maybe the USB cable is bad?\n",
2716 		port1);
2717 
2718 done:
2719 	if (!hub_is_superspeed(hub->hdev))
2720 		up_read(&ehci_cf_port_reset_rwsem);
2721 
2722 	return status;
2723 }
2724 
2725 /* Check if a port is power on */
port_is_power_on(struct usb_hub * hub,unsigned portstatus)2726 static int port_is_power_on(struct usb_hub *hub, unsigned portstatus)
2727 {
2728 	int ret = 0;
2729 
2730 	if (hub_is_superspeed(hub->hdev)) {
2731 		if (portstatus & USB_SS_PORT_STAT_POWER)
2732 			ret = 1;
2733 	} else {
2734 		if (portstatus & USB_PORT_STAT_POWER)
2735 			ret = 1;
2736 	}
2737 
2738 	return ret;
2739 }
2740 
2741 #ifdef	CONFIG_PM
2742 
2743 /* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
port_is_suspended(struct usb_hub * hub,unsigned portstatus)2744 static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
2745 {
2746 	int ret = 0;
2747 
2748 	if (hub_is_superspeed(hub->hdev)) {
2749 		if ((portstatus & USB_PORT_STAT_LINK_STATE)
2750 				== USB_SS_PORT_LS_U3)
2751 			ret = 1;
2752 	} else {
2753 		if (portstatus & USB_PORT_STAT_SUSPEND)
2754 			ret = 1;
2755 	}
2756 
2757 	return ret;
2758 }
2759 
2760 /* Determine whether the device on a port is ready for a normal resume,
2761  * is ready for a reset-resume, or should be disconnected.
2762  */
check_port_resume_type(struct usb_device * udev,struct usb_hub * hub,int port1,int status,unsigned portchange,unsigned portstatus)2763 static int check_port_resume_type(struct usb_device *udev,
2764 		struct usb_hub *hub, int port1,
2765 		int status, unsigned portchange, unsigned portstatus)
2766 {
2767 	/* Is the device still present? */
2768 	if (status || port_is_suspended(hub, portstatus) ||
2769 			!port_is_power_on(hub, portstatus) ||
2770 			!(portstatus & USB_PORT_STAT_CONNECTION)) {
2771 		if (status >= 0)
2772 			status = -ENODEV;
2773 	}
2774 
2775 	/* Can't do a normal resume if the port isn't enabled,
2776 	 * so try a reset-resume instead.
2777 	 */
2778 	else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
2779 		if (udev->persist_enabled)
2780 			udev->reset_resume = 1;
2781 		else
2782 			status = -ENODEV;
2783 	}
2784 
2785 	if (status) {
2786 		dev_dbg(hub->intfdev,
2787 				"port %d status %04x.%04x after resume, %d\n",
2788 				port1, portchange, portstatus, status);
2789 	} else if (udev->reset_resume) {
2790 
2791 		/* Late port handoff can set status-change bits */
2792 		if (portchange & USB_PORT_STAT_C_CONNECTION)
2793 			usb_clear_port_feature(hub->hdev, port1,
2794 					USB_PORT_FEAT_C_CONNECTION);
2795 		if (portchange & USB_PORT_STAT_C_ENABLE)
2796 			usb_clear_port_feature(hub->hdev, port1,
2797 					USB_PORT_FEAT_C_ENABLE);
2798 	}
2799 
2800 	return status;
2801 }
2802 
usb_disable_ltm(struct usb_device * udev)2803 int usb_disable_ltm(struct usb_device *udev)
2804 {
2805 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2806 
2807 	/* Check if the roothub and device supports LTM. */
2808 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2809 			!usb_device_supports_ltm(udev))
2810 		return 0;
2811 
2812 	/* Clear Feature LTM Enable can only be sent if the device is
2813 	 * configured.
2814 	 */
2815 	if (!udev->actconfig)
2816 		return 0;
2817 
2818 	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2819 			USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2820 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2821 			USB_CTRL_SET_TIMEOUT);
2822 }
2823 EXPORT_SYMBOL_GPL(usb_disable_ltm);
2824 
usb_enable_ltm(struct usb_device * udev)2825 void usb_enable_ltm(struct usb_device *udev)
2826 {
2827 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2828 
2829 	/* Check if the roothub and device supports LTM. */
2830 	if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2831 			!usb_device_supports_ltm(udev))
2832 		return;
2833 
2834 	/* Set Feature LTM Enable can only be sent if the device is
2835 	 * configured.
2836 	 */
2837 	if (!udev->actconfig)
2838 		return;
2839 
2840 	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2841 			USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2842 			USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2843 			USB_CTRL_SET_TIMEOUT);
2844 }
2845 EXPORT_SYMBOL_GPL(usb_enable_ltm);
2846 
2847 #ifdef	CONFIG_PM
2848 /*
2849  * usb_disable_function_remotewakeup - disable usb3.0
2850  * device's function remote wakeup
2851  * @udev: target device
2852  *
2853  * Assume there's only one function on the USB 3.0
2854  * device and disable remote wake for the first
2855  * interface. FIXME if the interface association
2856  * descriptor shows there's more than one function.
2857  */
usb_disable_function_remotewakeup(struct usb_device * udev)2858 static int usb_disable_function_remotewakeup(struct usb_device *udev)
2859 {
2860 	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2861 				USB_REQ_CLEAR_FEATURE, USB_RECIP_INTERFACE,
2862 				USB_INTRF_FUNC_SUSPEND,	0, NULL, 0,
2863 				USB_CTRL_SET_TIMEOUT);
2864 }
2865 
2866 /*
2867  * usb_port_suspend - suspend a usb device's upstream port
2868  * @udev: device that's no longer in active use, not a root hub
2869  * Context: must be able to sleep; device not locked; pm locks held
2870  *
2871  * Suspends a USB device that isn't in active use, conserving power.
2872  * Devices may wake out of a suspend, if anything important happens,
2873  * using the remote wakeup mechanism.  They may also be taken out of
2874  * suspend by the host, using usb_port_resume().  It's also routine
2875  * to disconnect devices while they are suspended.
2876  *
2877  * This only affects the USB hardware for a device; its interfaces
2878  * (and, for hubs, child devices) must already have been suspended.
2879  *
2880  * Selective port suspend reduces power; most suspended devices draw
2881  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
2882  * All devices below the suspended port are also suspended.
2883  *
2884  * Devices leave suspend state when the host wakes them up.  Some devices
2885  * also support "remote wakeup", where the device can activate the USB
2886  * tree above them to deliver data, such as a keypress or packet.  In
2887  * some cases, this wakes the USB host.
2888  *
2889  * Suspending OTG devices may trigger HNP, if that's been enabled
2890  * between a pair of dual-role devices.  That will change roles, such
2891  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
2892  *
2893  * Devices on USB hub ports have only one "suspend" state, corresponding
2894  * to ACPI D2, "may cause the device to lose some context".
2895  * State transitions include:
2896  *
2897  *   - suspend, resume ... when the VBUS power link stays live
2898  *   - suspend, disconnect ... VBUS lost
2899  *
2900  * Once VBUS drop breaks the circuit, the port it's using has to go through
2901  * normal re-enumeration procedures, starting with enabling VBUS power.
2902  * Other than re-initializing the hub (plug/unplug, except for root hubs),
2903  * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
2904  * timer, no SRP, no requests through sysfs.
2905  *
2906  * If Runtime PM isn't enabled or used, non-SuperSpeed devices really get
2907  * suspended only when their bus goes into global suspend (i.e., the root
2908  * hub is suspended).  Nevertheless, we change @udev->state to
2909  * USB_STATE_SUSPENDED as this is the device's "logical" state.  The actual
2910  * upstream port setting is stored in @udev->port_is_suspended.
2911  *
2912  * Returns 0 on success, else negative errno.
2913  */
usb_port_suspend(struct usb_device * udev,pm_message_t msg)2914 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
2915 {
2916 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
2917 	struct usb_port *port_dev = hub->ports[udev->portnum - 1];
2918 	enum pm_qos_flags_status pm_qos_stat;
2919 	int		port1 = udev->portnum;
2920 	int		status;
2921 	bool		really_suspend = true;
2922 
2923 	/* enable remote wakeup when appropriate; this lets the device
2924 	 * wake up the upstream hub (including maybe the root hub).
2925 	 *
2926 	 * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
2927 	 * we don't explicitly enable it here.
2928 	 */
2929 	if (udev->do_remote_wakeup) {
2930 		if (!hub_is_superspeed(hub->hdev)) {
2931 			status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2932 					USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
2933 					USB_DEVICE_REMOTE_WAKEUP, 0,
2934 					NULL, 0,
2935 					USB_CTRL_SET_TIMEOUT);
2936 		} else {
2937 			/* Assume there's only one function on the USB 3.0
2938 			 * device and enable remote wake for the first
2939 			 * interface. FIXME if the interface association
2940 			 * descriptor shows there's more than one function.
2941 			 */
2942 			status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2943 					USB_REQ_SET_FEATURE,
2944 					USB_RECIP_INTERFACE,
2945 					USB_INTRF_FUNC_SUSPEND,
2946 					USB_INTRF_FUNC_SUSPEND_RW |
2947 					USB_INTRF_FUNC_SUSPEND_LP,
2948 					NULL, 0,
2949 					USB_CTRL_SET_TIMEOUT);
2950 		}
2951 		if (status) {
2952 			dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
2953 					status);
2954 			/* bail if autosuspend is requested */
2955 			if (PMSG_IS_AUTO(msg))
2956 				return status;
2957 		}
2958 	}
2959 
2960 	/* disable USB2 hardware LPM */
2961 	if (udev->usb2_hw_lpm_enabled == 1)
2962 		usb_set_usb2_hardware_lpm(udev, 0);
2963 
2964 	if (usb_disable_ltm(udev)) {
2965 		dev_err(&udev->dev, "%s Failed to disable LTM before suspend\n.",
2966 				__func__);
2967 		return -ENOMEM;
2968 	}
2969 	if (usb_unlocked_disable_lpm(udev)) {
2970 		dev_err(&udev->dev, "%s Failed to disable LPM before suspend\n.",
2971 				__func__);
2972 		return -ENOMEM;
2973 	}
2974 
2975 	/* see 7.1.7.6 */
2976 	if (hub_is_superspeed(hub->hdev))
2977 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);
2978 	else if (PMSG_IS_AUTO(msg))
2979 		status = set_port_feature(hub->hdev, port1,
2980 						USB_PORT_FEAT_SUSPEND);
2981 	/*
2982 	 * For system suspend, we do not need to enable the suspend feature
2983 	 * on individual USB-2 ports.  The devices will automatically go
2984 	 * into suspend a few ms after the root hub stops sending packets.
2985 	 * The USB 2.0 spec calls this "global suspend".
2986 	 */
2987 	else {
2988 		really_suspend = false;
2989 		status = 0;
2990 	}
2991 	if (status) {
2992 		dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
2993 				port1, status);
2994 		/* paranoia:  "should not happen" */
2995 		if (udev->do_remote_wakeup) {
2996 			if (!hub_is_superspeed(hub->hdev)) {
2997 				(void) usb_control_msg(udev,
2998 						usb_sndctrlpipe(udev, 0),
2999 						USB_REQ_CLEAR_FEATURE,
3000 						USB_RECIP_DEVICE,
3001 						USB_DEVICE_REMOTE_WAKEUP, 0,
3002 						NULL, 0,
3003 						USB_CTRL_SET_TIMEOUT);
3004 			} else
3005 				(void) usb_disable_function_remotewakeup(udev);
3006 
3007 		}
3008 
3009 		/* Try to enable USB2 hardware LPM again */
3010 		if (udev->usb2_hw_lpm_capable == 1)
3011 			usb_set_usb2_hardware_lpm(udev, 1);
3012 
3013 		/* Try to enable USB3 LTM and LPM again */
3014 		usb_enable_ltm(udev);
3015 		usb_unlocked_enable_lpm(udev);
3016 
3017 		/* System sleep transitions should never fail */
3018 		if (!PMSG_IS_AUTO(msg))
3019 			status = 0;
3020 	} else {
3021 		/* device has up to 10 msec to fully suspend */
3022 		dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
3023 				(PMSG_IS_AUTO(msg) ? "auto-" : ""),
3024 				udev->do_remote_wakeup);
3025 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
3026 		if (really_suspend) {
3027 			udev->port_is_suspended = 1;
3028 			msleep(10);
3029 		}
3030 	}
3031 
3032 	/*
3033 	 * Check whether current status meets the requirement of
3034 	 * usb port power off mechanism
3035 	 */
3036 	pm_qos_stat = dev_pm_qos_flags(&port_dev->dev,
3037 			PM_QOS_FLAG_NO_POWER_OFF);
3038 	if (!udev->do_remote_wakeup
3039 			&& pm_qos_stat != PM_QOS_FLAGS_ALL
3040 			&& udev->persist_enabled
3041 			&& !status) {
3042 		pm_runtime_put_sync(&port_dev->dev);
3043 		port_dev->did_runtime_put = true;
3044 	}
3045 
3046 	usb_mark_last_busy(hub->hdev);
3047 	return status;
3048 }
3049 
3050 /*
3051  * If the USB "suspend" state is in use (rather than "global suspend"),
3052  * many devices will be individually taken out of suspend state using
3053  * special "resume" signaling.  This routine kicks in shortly after
3054  * hardware resume signaling is finished, either because of selective
3055  * resume (by host) or remote wakeup (by device) ... now see what changed
3056  * in the tree that's rooted at this device.
3057  *
3058  * If @udev->reset_resume is set then the device is reset before the
3059  * status check is done.
3060  */
finish_port_resume(struct usb_device * udev)3061 static int finish_port_resume(struct usb_device *udev)
3062 {
3063 	int	status = 0;
3064 	u16	devstatus = 0;
3065 
3066 	/* caller owns the udev device lock */
3067 	dev_dbg(&udev->dev, "%s\n",
3068 		udev->reset_resume ? "finish reset-resume" : "finish resume");
3069 
3070 	/* usb ch9 identifies four variants of SUSPENDED, based on what
3071 	 * state the device resumes to.  Linux currently won't see the
3072 	 * first two on the host side; they'd be inside hub_port_init()
3073 	 * during many timeouts, but khubd can't suspend until later.
3074 	 */
3075 	usb_set_device_state(udev, udev->actconfig
3076 			? USB_STATE_CONFIGURED
3077 			: USB_STATE_ADDRESS);
3078 
3079 	/* 10.5.4.5 says not to reset a suspended port if the attached
3080 	 * device is enabled for remote wakeup.  Hence the reset
3081 	 * operation is carried out here, after the port has been
3082 	 * resumed.
3083 	 */
3084 	if (udev->reset_resume)
3085  retry_reset_resume:
3086 		status = usb_reset_and_verify_device(udev);
3087 
3088  	/* 10.5.4.5 says be sure devices in the tree are still there.
3089  	 * For now let's assume the device didn't go crazy on resume,
3090 	 * and device drivers will know about any resume quirks.
3091 	 */
3092 	if (status == 0) {
3093 		devstatus = 0;
3094 		status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3095 		if (status >= 0)
3096 			status = (status > 0 ? 0 : -ENODEV);
3097 
3098 		/* If a normal resume failed, try doing a reset-resume */
3099 		if (status && !udev->reset_resume && udev->persist_enabled) {
3100 			dev_dbg(&udev->dev, "retry with reset-resume\n");
3101 			udev->reset_resume = 1;
3102 			goto retry_reset_resume;
3103 		}
3104 	}
3105 
3106 	if (status) {
3107 		dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
3108 				status);
3109 	/*
3110 	 * There are a few quirky devices which violate the standard
3111 	 * by claiming to have remote wakeup enabled after a reset,
3112 	 * which crash if the feature is cleared, hence check for
3113 	 * udev->reset_resume
3114 	 */
3115 	} else if (udev->actconfig && !udev->reset_resume) {
3116 		if (!hub_is_superspeed(udev->parent)) {
3117 			le16_to_cpus(&devstatus);
3118 			if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3119 				status = usb_control_msg(udev,
3120 						usb_sndctrlpipe(udev, 0),
3121 						USB_REQ_CLEAR_FEATURE,
3122 						USB_RECIP_DEVICE,
3123 						USB_DEVICE_REMOTE_WAKEUP, 0,
3124 						NULL, 0,
3125 						USB_CTRL_SET_TIMEOUT);
3126 		} else {
3127 			status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
3128 					&devstatus);
3129 			le16_to_cpus(&devstatus);
3130 			if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3131 					| USB_INTRF_STAT_FUNC_RW))
3132 				status =
3133 					usb_disable_function_remotewakeup(udev);
3134 		}
3135 
3136 		if (status)
3137 			dev_dbg(&udev->dev,
3138 				"disable remote wakeup, status %d\n",
3139 				status);
3140 		status = 0;
3141 	}
3142 	return status;
3143 }
3144 
3145 /*
3146  * usb_port_resume - re-activate a suspended usb device's upstream port
3147  * @udev: device to re-activate, not a root hub
3148  * Context: must be able to sleep; device not locked; pm locks held
3149  *
3150  * This will re-activate the suspended device, increasing power usage
3151  * while letting drivers communicate again with its endpoints.
3152  * USB resume explicitly guarantees that the power session between
3153  * the host and the device is the same as it was when the device
3154  * suspended.
3155  *
3156  * If @udev->reset_resume is set then this routine won't check that the
3157  * port is still enabled.  Furthermore, finish_port_resume() above will
3158  * reset @udev.  The end result is that a broken power session can be
3159  * recovered and @udev will appear to persist across a loss of VBUS power.
3160  *
3161  * For example, if a host controller doesn't maintain VBUS suspend current
3162  * during a system sleep or is reset when the system wakes up, all the USB
3163  * power sessions below it will be broken.  This is especially troublesome
3164  * for mass-storage devices containing mounted filesystems, since the
3165  * device will appear to have disconnected and all the memory mappings
3166  * to it will be lost.  Using the USB_PERSIST facility, the device can be
3167  * made to appear as if it had not disconnected.
3168  *
3169  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
3170  * every effort to insure that the same device is present after the
3171  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
3172  * quite possible for a device to remain unaltered but its media to be
3173  * changed.  If the user replaces a flash memory card while the system is
3174  * asleep, he will have only himself to blame when the filesystem on the
3175  * new card is corrupted and the system crashes.
3176  *
3177  * Returns 0 on success, else negative errno.
3178  */
usb_port_resume(struct usb_device * udev,pm_message_t msg)3179 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
3180 {
3181 	struct usb_hub	*hub = usb_hub_to_struct_hub(udev->parent);
3182 	struct usb_port *port_dev = hub->ports[udev->portnum  - 1];
3183 	int		port1 = udev->portnum;
3184 	int		status;
3185 	u16		portchange, portstatus;
3186 
3187 	if (port_dev->did_runtime_put) {
3188 		status = pm_runtime_get_sync(&port_dev->dev);
3189 		port_dev->did_runtime_put = false;
3190 		if (status < 0) {
3191 			dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
3192 					status);
3193 			return status;
3194 		}
3195 	}
3196 
3197 	/* Skip the initial Clear-Suspend step for a remote wakeup */
3198 	status = hub_port_status(hub, port1, &portstatus, &portchange);
3199 	if (status == 0 && !port_is_suspended(hub, portstatus))
3200 		goto SuspendCleared;
3201 
3202 	// dev_dbg(hub->intfdev, "resume port %d\n", port1);
3203 
3204 	set_bit(port1, hub->busy_bits);
3205 
3206 	/* see 7.1.7.7; affects power usage, but not budgeting */
3207 	if (hub_is_superspeed(hub->hdev))
3208 		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
3209 	else
3210 		status = usb_clear_port_feature(hub->hdev,
3211 				port1, USB_PORT_FEAT_SUSPEND);
3212 	if (status) {
3213 		dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
3214 				port1, status);
3215 	} else {
3216 		/* drive resume for at least 20 msec */
3217 		dev_dbg(&udev->dev, "usb %sresume\n",
3218 				(PMSG_IS_AUTO(msg) ? "auto-" : ""));
3219 		msleep(25);
3220 
3221 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
3222 		 * stop resume signaling.  Then finish the resume
3223 		 * sequence.
3224 		 */
3225 		status = hub_port_status(hub, port1, &portstatus, &portchange);
3226 
3227 		/* TRSMRCY = 10 msec */
3228 		msleep(10);
3229 	}
3230 
3231  SuspendCleared:
3232 	if (status == 0) {
3233 		udev->port_is_suspended = 0;
3234 		if (hub_is_superspeed(hub->hdev)) {
3235 			if (portchange & USB_PORT_STAT_C_LINK_STATE)
3236 				usb_clear_port_feature(hub->hdev, port1,
3237 					USB_PORT_FEAT_C_PORT_LINK_STATE);
3238 		} else {
3239 			if (portchange & USB_PORT_STAT_C_SUSPEND)
3240 				usb_clear_port_feature(hub->hdev, port1,
3241 						USB_PORT_FEAT_C_SUSPEND);
3242 		}
3243 	}
3244 
3245 	clear_bit(port1, hub->busy_bits);
3246 
3247 	status = check_port_resume_type(udev,
3248 			hub, port1, status, portchange, portstatus);
3249 	if (status == 0)
3250 		status = finish_port_resume(udev);
3251 	if (status < 0) {
3252 		dev_dbg(&udev->dev, "can't resume, status %d\n", status);
3253 		hub_port_logical_disconnect(hub, port1);
3254 	} else  {
3255 		/* Try to enable USB2 hardware LPM */
3256 		if (udev->usb2_hw_lpm_capable == 1)
3257 			usb_set_usb2_hardware_lpm(udev, 1);
3258 
3259 		/* Try to enable USB3 LTM and LPM */
3260 		usb_enable_ltm(udev);
3261 		usb_unlocked_enable_lpm(udev);
3262 	}
3263 
3264 	return status;
3265 }
3266 
3267 #endif	/* CONFIG_PM */
3268 
3269 #ifdef	CONFIG_PM_RUNTIME
3270 
3271 /* caller has locked udev */
usb_remote_wakeup(struct usb_device * udev)3272 int usb_remote_wakeup(struct usb_device *udev)
3273 {
3274 	int	status = 0;
3275 
3276 	if (udev->state == USB_STATE_SUSPENDED) {
3277 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
3278 		status = usb_autoresume_device(udev);
3279 		if (status == 0) {
3280 			/* Let the drivers do their thing, then... */
3281 			usb_autosuspend_device(udev);
3282 		}
3283 	}
3284 	return status;
3285 }
3286 
3287 #endif
3288 
check_ports_changed(struct usb_hub * hub)3289 static int check_ports_changed(struct usb_hub *hub)
3290 {
3291 	int port1;
3292 
3293 	for (port1 = 1; port1 <= hub->hdev->maxchild; ++port1) {
3294 		u16 portstatus, portchange;
3295 		int status;
3296 
3297 		status = hub_port_status(hub, port1, &portstatus, &portchange);
3298 		if (!status && portchange)
3299 			return 1;
3300 	}
3301 	return 0;
3302 }
3303 
hub_suspend(struct usb_interface * intf,pm_message_t msg)3304 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
3305 {
3306 	struct usb_hub		*hub = usb_get_intfdata (intf);
3307 	struct usb_device	*hdev = hub->hdev;
3308 	unsigned		port1;
3309 	int			status;
3310 
3311 	/* Warn if children aren't already suspended */
3312 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3313 		struct usb_device	*udev;
3314 
3315 		udev = hub->ports[port1 - 1]->child;
3316 		if (udev && udev->can_submit) {
3317 			dev_warn(&intf->dev, "port %d nyet suspended\n", port1);
3318 			if (PMSG_IS_AUTO(msg))
3319 				return -EBUSY;
3320 		}
3321 	}
3322 
3323 	if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
3324 		/* check if there are changes pending on hub ports */
3325 		if (check_ports_changed(hub)) {
3326 			if (PMSG_IS_AUTO(msg))
3327 				return -EBUSY;
3328 			pm_wakeup_event(&hdev->dev, 2000);
3329 		}
3330 	}
3331 
3332 	if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
3333 		/* Enable hub to send remote wakeup for all ports. */
3334 		for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3335 			status = set_port_feature(hdev,
3336 					port1 |
3337 					USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
3338 					USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
3339 					USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
3340 					USB_PORT_FEAT_REMOTE_WAKE_MASK);
3341 		}
3342 	}
3343 
3344 	dev_dbg(&intf->dev, "%s\n", __func__);
3345 
3346 	/* stop khubd and related activity */
3347 	hub_quiesce(hub, HUB_SUSPEND);
3348 	return 0;
3349 }
3350 
hub_resume(struct usb_interface * intf)3351 static int hub_resume(struct usb_interface *intf)
3352 {
3353 	struct usb_hub *hub = usb_get_intfdata(intf);
3354 
3355 	dev_dbg(&intf->dev, "%s\n", __func__);
3356 	hub_activate(hub, HUB_RESUME);
3357 	return 0;
3358 }
3359 
hub_reset_resume(struct usb_interface * intf)3360 static int hub_reset_resume(struct usb_interface *intf)
3361 {
3362 	struct usb_hub *hub = usb_get_intfdata(intf);
3363 
3364 	dev_dbg(&intf->dev, "%s\n", __func__);
3365 	hub_activate(hub, HUB_RESET_RESUME);
3366 	return 0;
3367 }
3368 
3369 /**
3370  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
3371  * @rhdev: struct usb_device for the root hub
3372  *
3373  * The USB host controller driver calls this function when its root hub
3374  * is resumed and Vbus power has been interrupted or the controller
3375  * has been reset.  The routine marks @rhdev as having lost power.
3376  * When the hub driver is resumed it will take notice and carry out
3377  * power-session recovery for all the "USB-PERSIST"-enabled child devices;
3378  * the others will be disconnected.
3379  */
usb_root_hub_lost_power(struct usb_device * rhdev)3380 void usb_root_hub_lost_power(struct usb_device *rhdev)
3381 {
3382 	dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
3383 	rhdev->reset_resume = 1;
3384 }
3385 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
3386 
3387 static const char * const usb3_lpm_names[]  = {
3388 	"U0",
3389 	"U1",
3390 	"U2",
3391 	"U3",
3392 };
3393 
3394 /*
3395  * Send a Set SEL control transfer to the device, prior to enabling
3396  * device-initiated U1 or U2.  This lets the device know the exit latencies from
3397  * the time the device initiates a U1 or U2 exit, to the time it will receive a
3398  * packet from the host.
3399  *
3400  * This function will fail if the SEL or PEL values for udev are greater than
3401  * the maximum allowed values for the link state to be enabled.
3402  */
usb_req_set_sel(struct usb_device * udev,enum usb3_link_state state)3403 static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state)
3404 {
3405 	struct usb_set_sel_req *sel_values;
3406 	unsigned long long u1_sel;
3407 	unsigned long long u1_pel;
3408 	unsigned long long u2_sel;
3409 	unsigned long long u2_pel;
3410 	int ret;
3411 
3412 	/* Convert SEL and PEL stored in ns to us */
3413 	u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
3414 	u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
3415 	u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
3416 	u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);
3417 
3418 	/*
3419 	 * Make sure that the calculated SEL and PEL values for the link
3420 	 * state we're enabling aren't bigger than the max SEL/PEL
3421 	 * value that will fit in the SET SEL control transfer.
3422 	 * Otherwise the device would get an incorrect idea of the exit
3423 	 * latency for the link state, and could start a device-initiated
3424 	 * U1/U2 when the exit latencies are too high.
3425 	 */
3426 	if ((state == USB3_LPM_U1 &&
3427 				(u1_sel > USB3_LPM_MAX_U1_SEL_PEL ||
3428 				 u1_pel > USB3_LPM_MAX_U1_SEL_PEL)) ||
3429 			(state == USB3_LPM_U2 &&
3430 			 (u2_sel > USB3_LPM_MAX_U2_SEL_PEL ||
3431 			  u2_pel > USB3_LPM_MAX_U2_SEL_PEL))) {
3432 		dev_dbg(&udev->dev, "Device-initiated %s disabled due to long SEL %llu us or PEL %llu us\n",
3433 				usb3_lpm_names[state], u1_sel, u1_pel);
3434 		return -EINVAL;
3435 	}
3436 
3437 	/*
3438 	 * If we're enabling device-initiated LPM for one link state,
3439 	 * but the other link state has a too high SEL or PEL value,
3440 	 * just set those values to the max in the Set SEL request.
3441 	 */
3442 	if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL)
3443 		u1_sel = USB3_LPM_MAX_U1_SEL_PEL;
3444 
3445 	if (u1_pel > USB3_LPM_MAX_U1_SEL_PEL)
3446 		u1_pel = USB3_LPM_MAX_U1_SEL_PEL;
3447 
3448 	if (u2_sel > USB3_LPM_MAX_U2_SEL_PEL)
3449 		u2_sel = USB3_LPM_MAX_U2_SEL_PEL;
3450 
3451 	if (u2_pel > USB3_LPM_MAX_U2_SEL_PEL)
3452 		u2_pel = USB3_LPM_MAX_U2_SEL_PEL;
3453 
3454 	/*
3455 	 * usb_enable_lpm() can be called as part of a failed device reset,
3456 	 * which may be initiated by an error path of a mass storage driver.
3457 	 * Therefore, use GFP_NOIO.
3458 	 */
3459 	sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
3460 	if (!sel_values)
3461 		return -ENOMEM;
3462 
3463 	sel_values->u1_sel = u1_sel;
3464 	sel_values->u1_pel = u1_pel;
3465 	sel_values->u2_sel = cpu_to_le16(u2_sel);
3466 	sel_values->u2_pel = cpu_to_le16(u2_pel);
3467 
3468 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3469 			USB_REQ_SET_SEL,
3470 			USB_RECIP_DEVICE,
3471 			0, 0,
3472 			sel_values, sizeof *(sel_values),
3473 			USB_CTRL_SET_TIMEOUT);
3474 	kfree(sel_values);
3475 	return ret;
3476 }
3477 
3478 /*
3479  * Enable or disable device-initiated U1 or U2 transitions.
3480  */
usb_set_device_initiated_lpm(struct usb_device * udev,enum usb3_link_state state,bool enable)3481 static int usb_set_device_initiated_lpm(struct usb_device *udev,
3482 		enum usb3_link_state state, bool enable)
3483 {
3484 	int ret;
3485 	int feature;
3486 
3487 	switch (state) {
3488 	case USB3_LPM_U1:
3489 		feature = USB_DEVICE_U1_ENABLE;
3490 		break;
3491 	case USB3_LPM_U2:
3492 		feature = USB_DEVICE_U2_ENABLE;
3493 		break;
3494 	default:
3495 		dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n",
3496 				__func__, enable ? "enable" : "disable");
3497 		return -EINVAL;
3498 	}
3499 
3500 	if (udev->state != USB_STATE_CONFIGURED) {
3501 		dev_dbg(&udev->dev, "%s: Can't %s %s state "
3502 				"for unconfigured device.\n",
3503 				__func__, enable ? "enable" : "disable",
3504 				usb3_lpm_names[state]);
3505 		return 0;
3506 	}
3507 
3508 	if (enable) {
3509 		/*
3510 		 * Now send the control transfer to enable device-initiated LPM
3511 		 * for either U1 or U2.
3512 		 */
3513 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3514 				USB_REQ_SET_FEATURE,
3515 				USB_RECIP_DEVICE,
3516 				feature,
3517 				0, NULL, 0,
3518 				USB_CTRL_SET_TIMEOUT);
3519 	} else {
3520 		ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3521 				USB_REQ_CLEAR_FEATURE,
3522 				USB_RECIP_DEVICE,
3523 				feature,
3524 				0, NULL, 0,
3525 				USB_CTRL_SET_TIMEOUT);
3526 	}
3527 	if (ret < 0) {
3528 		dev_warn(&udev->dev, "%s of device-initiated %s failed.\n",
3529 				enable ? "Enable" : "Disable",
3530 				usb3_lpm_names[state]);
3531 		return -EBUSY;
3532 	}
3533 	return 0;
3534 }
3535 
usb_set_lpm_timeout(struct usb_device * udev,enum usb3_link_state state,int timeout)3536 static int usb_set_lpm_timeout(struct usb_device *udev,
3537 		enum usb3_link_state state, int timeout)
3538 {
3539 	int ret;
3540 	int feature;
3541 
3542 	switch (state) {
3543 	case USB3_LPM_U1:
3544 		feature = USB_PORT_FEAT_U1_TIMEOUT;
3545 		break;
3546 	case USB3_LPM_U2:
3547 		feature = USB_PORT_FEAT_U2_TIMEOUT;
3548 		break;
3549 	default:
3550 		dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n",
3551 				__func__);
3552 		return -EINVAL;
3553 	}
3554 
3555 	if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT &&
3556 			timeout != USB3_LPM_DEVICE_INITIATED) {
3557 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, "
3558 				"which is a reserved value.\n",
3559 				usb3_lpm_names[state], timeout);
3560 		return -EINVAL;
3561 	}
3562 
3563 	ret = set_port_feature(udev->parent,
3564 			USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum,
3565 			feature);
3566 	if (ret < 0) {
3567 		dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x,"
3568 				"error code %i\n", usb3_lpm_names[state],
3569 				timeout, ret);
3570 		return -EBUSY;
3571 	}
3572 	if (state == USB3_LPM_U1)
3573 		udev->u1_params.timeout = timeout;
3574 	else
3575 		udev->u2_params.timeout = timeout;
3576 	return 0;
3577 }
3578 
3579 /*
3580  * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated
3581  * U1/U2 entry.
3582  *
3583  * We will attempt to enable U1 or U2, but there are no guarantees that the
3584  * control transfers to set the hub timeout or enable device-initiated U1/U2
3585  * will be successful.
3586  *
3587  * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI
3588  * driver know about it.  If that call fails, it should be harmless, and just
3589  * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency.
3590  */
usb_enable_link_state(struct usb_hcd * hcd,struct usb_device * udev,enum usb3_link_state state)3591 static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3592 		enum usb3_link_state state)
3593 {
3594 	int timeout, ret;
3595 	__u8 u1_mel = udev->bos->ss_cap->bU1devExitLat;
3596 	__le16 u2_mel = udev->bos->ss_cap->bU2DevExitLat;
3597 
3598 	/* If the device says it doesn't have *any* exit latency to come out of
3599 	 * U1 or U2, it's probably lying.  Assume it doesn't implement that link
3600 	 * state.
3601 	 */
3602 	if ((state == USB3_LPM_U1 && u1_mel == 0) ||
3603 			(state == USB3_LPM_U2 && u2_mel == 0))
3604 		return;
3605 
3606 	/*
3607 	 * First, let the device know about the exit latencies
3608 	 * associated with the link state we're about to enable.
3609 	 */
3610 	ret = usb_req_set_sel(udev, state);
3611 	if (ret < 0) {
3612 		dev_warn(&udev->dev, "Set SEL for device-initiated %s failed.\n",
3613 				usb3_lpm_names[state]);
3614 		return;
3615 	}
3616 
3617 	/* We allow the host controller to set the U1/U2 timeout internally
3618 	 * first, so that it can change its schedule to account for the
3619 	 * additional latency to send data to a device in a lower power
3620 	 * link state.
3621 	 */
3622 	timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state);
3623 
3624 	/* xHCI host controller doesn't want to enable this LPM state. */
3625 	if (timeout == 0)
3626 		return;
3627 
3628 	if (timeout < 0) {
3629 		dev_warn(&udev->dev, "Could not enable %s link state, "
3630 				"xHCI error %i.\n", usb3_lpm_names[state],
3631 				timeout);
3632 		return;
3633 	}
3634 
3635 	if (usb_set_lpm_timeout(udev, state, timeout))
3636 		/* If we can't set the parent hub U1/U2 timeout,
3637 		 * device-initiated LPM won't be allowed either, so let the xHCI
3638 		 * host know that this link state won't be enabled.
3639 		 */
3640 		hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
3641 
3642 	/* Only a configured device will accept the Set Feature U1/U2_ENABLE */
3643 	else if (udev->actconfig)
3644 		usb_set_device_initiated_lpm(udev, state, true);
3645 
3646 }
3647 
3648 /*
3649  * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated
3650  * U1/U2 entry.
3651  *
3652  * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry.
3653  * If zero is returned, the parent will not allow the link to go into U1/U2.
3654  *
3655  * If zero is returned, device-initiated U1/U2 entry may still be enabled, but
3656  * it won't have an effect on the bus link state because the parent hub will
3657  * still disallow device-initiated U1/U2 entry.
3658  *
3659  * If zero is returned, the xHCI host controller may still think U1/U2 entry is
3660  * possible.  The result will be slightly more bus bandwidth will be taken up
3661  * (to account for U1/U2 exit latency), but it should be harmless.
3662  */
usb_disable_link_state(struct usb_hcd * hcd,struct usb_device * udev,enum usb3_link_state state)3663 static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3664 		enum usb3_link_state state)
3665 {
3666 	int feature;
3667 
3668 	switch (state) {
3669 	case USB3_LPM_U1:
3670 		feature = USB_PORT_FEAT_U1_TIMEOUT;
3671 		break;
3672 	case USB3_LPM_U2:
3673 		feature = USB_PORT_FEAT_U2_TIMEOUT;
3674 		break;
3675 	default:
3676 		dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n",
3677 				__func__);
3678 		return -EINVAL;
3679 	}
3680 
3681 	if (usb_set_lpm_timeout(udev, state, 0))
3682 		return -EBUSY;
3683 
3684 	usb_set_device_initiated_lpm(udev, state, false);
3685 
3686 	if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state))
3687 		dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
3688 				"bus schedule bandwidth may be impacted.\n",
3689 				usb3_lpm_names[state]);
3690 	return 0;
3691 }
3692 
3693 /*
3694  * Disable hub-initiated and device-initiated U1 and U2 entry.
3695  * Caller must own the bandwidth_mutex.
3696  *
3697  * This will call usb_enable_lpm() on failure, which will decrement
3698  * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero.
3699  */
usb_disable_lpm(struct usb_device * udev)3700 int usb_disable_lpm(struct usb_device *udev)
3701 {
3702 	struct usb_hcd *hcd;
3703 
3704 	if (!udev || !udev->parent ||
3705 			udev->speed != USB_SPEED_SUPER ||
3706 			!udev->lpm_capable)
3707 		return 0;
3708 
3709 	hcd = bus_to_hcd(udev->bus);
3710 	if (!hcd || !hcd->driver->disable_usb3_lpm_timeout)
3711 		return 0;
3712 
3713 	udev->lpm_disable_count++;
3714 	if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
3715 		return 0;
3716 
3717 	/* If LPM is enabled, attempt to disable it. */
3718 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
3719 		goto enable_lpm;
3720 	if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
3721 		goto enable_lpm;
3722 
3723 	return 0;
3724 
3725 enable_lpm:
3726 	usb_enable_lpm(udev);
3727 	return -EBUSY;
3728 }
3729 EXPORT_SYMBOL_GPL(usb_disable_lpm);
3730 
3731 /* Grab the bandwidth_mutex before calling usb_disable_lpm() */
usb_unlocked_disable_lpm(struct usb_device * udev)3732 int usb_unlocked_disable_lpm(struct usb_device *udev)
3733 {
3734 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3735 	int ret;
3736 
3737 	if (!hcd)
3738 		return -EINVAL;
3739 
3740 	mutex_lock(hcd->bandwidth_mutex);
3741 	ret = usb_disable_lpm(udev);
3742 	mutex_unlock(hcd->bandwidth_mutex);
3743 
3744 	return ret;
3745 }
3746 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
3747 
3748 /*
3749  * Attempt to enable device-initiated and hub-initiated U1 and U2 entry.  The
3750  * xHCI host policy may prevent U1 or U2 from being enabled.
3751  *
3752  * Other callers may have disabled link PM, so U1 and U2 entry will be disabled
3753  * until the lpm_disable_count drops to zero.  Caller must own the
3754  * bandwidth_mutex.
3755  */
usb_enable_lpm(struct usb_device * udev)3756 void usb_enable_lpm(struct usb_device *udev)
3757 {
3758 	struct usb_hcd *hcd;
3759 
3760 	if (!udev || !udev->parent ||
3761 			udev->speed != USB_SPEED_SUPER ||
3762 			!udev->lpm_capable)
3763 		return;
3764 
3765 	udev->lpm_disable_count--;
3766 	hcd = bus_to_hcd(udev->bus);
3767 	/* Double check that we can both enable and disable LPM.
3768 	 * Device must be configured to accept set feature U1/U2 timeout.
3769 	 */
3770 	if (!hcd || !hcd->driver->enable_usb3_lpm_timeout ||
3771 			!hcd->driver->disable_usb3_lpm_timeout)
3772 		return;
3773 
3774 	if (udev->lpm_disable_count > 0)
3775 		return;
3776 
3777 	usb_enable_link_state(hcd, udev, USB3_LPM_U1);
3778 	usb_enable_link_state(hcd, udev, USB3_LPM_U2);
3779 }
3780 EXPORT_SYMBOL_GPL(usb_enable_lpm);
3781 
3782 /* Grab the bandwidth_mutex before calling usb_enable_lpm() */
usb_unlocked_enable_lpm(struct usb_device * udev)3783 void usb_unlocked_enable_lpm(struct usb_device *udev)
3784 {
3785 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3786 
3787 	if (!hcd)
3788 		return;
3789 
3790 	mutex_lock(hcd->bandwidth_mutex);
3791 	usb_enable_lpm(udev);
3792 	mutex_unlock(hcd->bandwidth_mutex);
3793 }
3794 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
3795 
3796 
3797 #else	/* CONFIG_PM */
3798 
3799 #define hub_suspend		NULL
3800 #define hub_resume		NULL
3801 #define hub_reset_resume	NULL
3802 
usb_disable_lpm(struct usb_device * udev)3803 int usb_disable_lpm(struct usb_device *udev)
3804 {
3805 	return 0;
3806 }
3807 EXPORT_SYMBOL_GPL(usb_disable_lpm);
3808 
usb_enable_lpm(struct usb_device * udev)3809 void usb_enable_lpm(struct usb_device *udev) { }
3810 EXPORT_SYMBOL_GPL(usb_enable_lpm);
3811 
usb_unlocked_disable_lpm(struct usb_device * udev)3812 int usb_unlocked_disable_lpm(struct usb_device *udev)
3813 {
3814 	return 0;
3815 }
3816 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
3817 
usb_unlocked_enable_lpm(struct usb_device * udev)3818 void usb_unlocked_enable_lpm(struct usb_device *udev) { }
3819 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
3820 
usb_disable_ltm(struct usb_device * udev)3821 int usb_disable_ltm(struct usb_device *udev)
3822 {
3823 	return 0;
3824 }
3825 EXPORT_SYMBOL_GPL(usb_disable_ltm);
3826 
usb_enable_ltm(struct usb_device * udev)3827 void usb_enable_ltm(struct usb_device *udev) { }
3828 EXPORT_SYMBOL_GPL(usb_enable_ltm);
3829 #endif
3830 
3831 
3832 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
3833  *
3834  * Between connect detection and reset signaling there must be a delay
3835  * of 100ms at least for debounce and power-settling.  The corresponding
3836  * timer shall restart whenever the downstream port detects a disconnect.
3837  *
3838  * Apparently there are some bluetooth and irda-dongles and a number of
3839  * low-speed devices for which this debounce period may last over a second.
3840  * Not covered by the spec - but easy to deal with.
3841  *
3842  * This implementation uses a 1500ms total debounce timeout; if the
3843  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
3844  * every 25ms for transient disconnects.  When the port status has been
3845  * unchanged for 100ms it returns the port status.
3846  */
hub_port_debounce(struct usb_hub * hub,int port1,bool must_be_connected)3847 int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
3848 {
3849 	int ret;
3850 	int total_time, stable_time = 0;
3851 	u16 portchange, portstatus;
3852 	unsigned connection = 0xffff;
3853 
3854 	for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
3855 		ret = hub_port_status(hub, port1, &portstatus, &portchange);
3856 		if (ret < 0)
3857 			return ret;
3858 
3859 		if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
3860 		     (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
3861 			if (!must_be_connected ||
3862 			     (connection == USB_PORT_STAT_CONNECTION))
3863 				stable_time += HUB_DEBOUNCE_STEP;
3864 			if (stable_time >= HUB_DEBOUNCE_STABLE)
3865 				break;
3866 		} else {
3867 			stable_time = 0;
3868 			connection = portstatus & USB_PORT_STAT_CONNECTION;
3869 		}
3870 
3871 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
3872 			usb_clear_port_feature(hub->hdev, port1,
3873 					USB_PORT_FEAT_C_CONNECTION);
3874 		}
3875 
3876 		if (total_time >= HUB_DEBOUNCE_TIMEOUT)
3877 			break;
3878 		msleep(HUB_DEBOUNCE_STEP);
3879 	}
3880 
3881 	dev_dbg (hub->intfdev,
3882 		"debounce: port %d: total %dms stable %dms status 0x%x\n",
3883 		port1, total_time, stable_time, portstatus);
3884 
3885 	if (stable_time < HUB_DEBOUNCE_STABLE)
3886 		return -ETIMEDOUT;
3887 	return portstatus;
3888 }
3889 
usb_ep0_reinit(struct usb_device * udev)3890 void usb_ep0_reinit(struct usb_device *udev)
3891 {
3892 	usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
3893 	usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
3894 	usb_enable_endpoint(udev, &udev->ep0, true);
3895 }
3896 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
3897 
3898 #define usb_sndaddr0pipe()	(PIPE_CONTROL << 30)
3899 #define usb_rcvaddr0pipe()	((PIPE_CONTROL << 30) | USB_DIR_IN)
3900 
hub_set_address(struct usb_device * udev,int devnum)3901 static int hub_set_address(struct usb_device *udev, int devnum)
3902 {
3903 	int retval;
3904 	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
3905 
3906 	/*
3907 	 * The host controller will choose the device address,
3908 	 * instead of the core having chosen it earlier
3909 	 */
3910 	if (!hcd->driver->address_device && devnum <= 1)
3911 		return -EINVAL;
3912 	if (udev->state == USB_STATE_ADDRESS)
3913 		return 0;
3914 	if (udev->state != USB_STATE_DEFAULT)
3915 		return -EINVAL;
3916 	if (hcd->driver->address_device)
3917 		retval = hcd->driver->address_device(hcd, udev);
3918 	else
3919 		retval = usb_control_msg(udev, usb_sndaddr0pipe(),
3920 				USB_REQ_SET_ADDRESS, 0, devnum, 0,
3921 				NULL, 0, USB_CTRL_SET_TIMEOUT);
3922 	if (retval == 0) {
3923 		update_devnum(udev, devnum);
3924 		/* Device now using proper address. */
3925 		usb_set_device_state(udev, USB_STATE_ADDRESS);
3926 		usb_ep0_reinit(udev);
3927 	}
3928 	return retval;
3929 }
3930 
3931 /* Reset device, (re)assign address, get device descriptor.
3932  * Device connection must be stable, no more debouncing needed.
3933  * Returns device in USB_STATE_ADDRESS, except on error.
3934  *
3935  * If this is called for an already-existing device (as part of
3936  * usb_reset_and_verify_device), the caller must own the device lock.  For a
3937  * newly detected device that is not accessible through any global
3938  * pointers, it's not necessary to lock the device.
3939  */
3940 static int
hub_port_init(struct usb_hub * hub,struct usb_device * udev,int port1,int retry_counter)3941 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
3942 		int retry_counter)
3943 {
3944 	static DEFINE_MUTEX(usb_address0_mutex);
3945 
3946 	struct usb_device	*hdev = hub->hdev;
3947 	struct usb_hcd		*hcd = bus_to_hcd(hdev->bus);
3948 	int			i, j, retval;
3949 	unsigned		delay = HUB_SHORT_RESET_TIME;
3950 	enum usb_device_speed	oldspeed = udev->speed;
3951 	const char		*speed;
3952 	int			devnum = udev->devnum;
3953 
3954 	/* root hub ports have a slightly longer reset period
3955 	 * (from USB 2.0 spec, section 7.1.7.5)
3956 	 */
3957 	if (!hdev->parent) {
3958 		delay = HUB_ROOT_RESET_TIME;
3959 		if (port1 == hdev->bus->otg_port)
3960 			hdev->bus->b_hnp_enable = 0;
3961 	}
3962 
3963 	/* Some low speed devices have problems with the quick delay, so */
3964 	/*  be a bit pessimistic with those devices. RHbug #23670 */
3965 	if (oldspeed == USB_SPEED_LOW)
3966 		delay = HUB_LONG_RESET_TIME;
3967 
3968 	mutex_lock(&usb_address0_mutex);
3969 
3970 	/* Reset the device; full speed may morph to high speed */
3971 	/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
3972 	retval = hub_port_reset(hub, port1, udev, delay, false);
3973 	if (retval < 0)		/* error or disconnect */
3974 		goto fail;
3975 	/* success, speed is known */
3976 
3977 	retval = -ENODEV;
3978 
3979 	if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
3980 		dev_dbg(&udev->dev, "device reset changed speed!\n");
3981 		goto fail;
3982 	}
3983 	oldspeed = udev->speed;
3984 
3985 	/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
3986 	 * it's fixed size except for full speed devices.
3987 	 * For Wireless USB devices, ep0 max packet is always 512 (tho
3988 	 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
3989 	 */
3990 	switch (udev->speed) {
3991 	case USB_SPEED_SUPER:
3992 	case USB_SPEED_WIRELESS:	/* fixed at 512 */
3993 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
3994 		break;
3995 	case USB_SPEED_HIGH:		/* fixed at 64 */
3996 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
3997 		break;
3998 	case USB_SPEED_FULL:		/* 8, 16, 32, or 64 */
3999 		/* to determine the ep0 maxpacket size, try to read
4000 		 * the device descriptor to get bMaxPacketSize0 and
4001 		 * then correct our initial guess.
4002 		 */
4003 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4004 		break;
4005 	case USB_SPEED_LOW:		/* fixed at 8 */
4006 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
4007 		break;
4008 	default:
4009 		goto fail;
4010 	}
4011 
4012 	if (udev->speed == USB_SPEED_WIRELESS)
4013 		speed = "variable speed Wireless";
4014 	else
4015 		speed = usb_speed_string(udev->speed);
4016 
4017 	if (udev->speed != USB_SPEED_SUPER)
4018 		dev_info(&udev->dev,
4019 				"%s %s USB device number %d using %s\n",
4020 				(udev->config) ? "reset" : "new", speed,
4021 				devnum, udev->bus->controller->driver->name);
4022 
4023 	/* Set up TT records, if needed  */
4024 	if (hdev->tt) {
4025 		udev->tt = hdev->tt;
4026 		udev->ttport = hdev->ttport;
4027 	} else if (udev->speed != USB_SPEED_HIGH
4028 			&& hdev->speed == USB_SPEED_HIGH) {
4029 		if (!hub->tt.hub) {
4030 			dev_err(&udev->dev, "parent hub has no TT\n");
4031 			retval = -EINVAL;
4032 			goto fail;
4033 		}
4034 		udev->tt = &hub->tt;
4035 		udev->ttport = port1;
4036 	}
4037 
4038 	/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
4039 	 * Because device hardware and firmware is sometimes buggy in
4040 	 * this area, and this is how Linux has done it for ages.
4041 	 * Change it cautiously.
4042 	 *
4043 	 * NOTE:  If USE_NEW_SCHEME() is true we will start by issuing
4044 	 * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
4045 	 * so it may help with some non-standards-compliant devices.
4046 	 * Otherwise we start with SET_ADDRESS and then try to read the
4047 	 * first 8 bytes of the device descriptor to get the ep0 maxpacket
4048 	 * value.
4049 	 */
4050 	for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
4051 		if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3)) {
4052 			struct usb_device_descriptor *buf;
4053 			int r = 0;
4054 
4055 #define GET_DESCRIPTOR_BUFSIZE	64
4056 			buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
4057 			if (!buf) {
4058 				retval = -ENOMEM;
4059 				continue;
4060 			}
4061 
4062 			/* Retry on all errors; some devices are flakey.
4063 			 * 255 is for WUSB devices, we actually need to use
4064 			 * 512 (WUSB1.0[4.8.1]).
4065 			 */
4066 			for (j = 0; j < 3; ++j) {
4067 				buf->bMaxPacketSize0 = 0;
4068 				r = usb_control_msg(udev, usb_rcvaddr0pipe(),
4069 					USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
4070 					USB_DT_DEVICE << 8, 0,
4071 					buf, GET_DESCRIPTOR_BUFSIZE,
4072 					initial_descriptor_timeout);
4073 				switch (buf->bMaxPacketSize0) {
4074 				case 8: case 16: case 32: case 64: case 255:
4075 					if (buf->bDescriptorType ==
4076 							USB_DT_DEVICE) {
4077 						r = 0;
4078 						break;
4079 					}
4080 					/* FALL THROUGH */
4081 				default:
4082 					if (r == 0)
4083 						r = -EPROTO;
4084 					break;
4085 				}
4086 				if (r == 0)
4087 					break;
4088 			}
4089 			udev->descriptor.bMaxPacketSize0 =
4090 					buf->bMaxPacketSize0;
4091 			kfree(buf);
4092 
4093 			retval = hub_port_reset(hub, port1, udev, delay, false);
4094 			if (retval < 0)		/* error or disconnect */
4095 				goto fail;
4096 			if (oldspeed != udev->speed) {
4097 				dev_dbg(&udev->dev,
4098 					"device reset changed speed!\n");
4099 				retval = -ENODEV;
4100 				goto fail;
4101 			}
4102 			if (r) {
4103 				if (r != -ENODEV)
4104 					dev_err(&udev->dev, "device descriptor read/64, error %d\n",
4105 							r);
4106 				retval = -EMSGSIZE;
4107 				continue;
4108 			}
4109 #undef GET_DESCRIPTOR_BUFSIZE
4110 		}
4111 
4112  		/*
4113  		 * If device is WUSB, we already assigned an
4114  		 * unauthorized address in the Connect Ack sequence;
4115  		 * authorization will assign the final address.
4116  		 */
4117 		if (udev->wusb == 0) {
4118 			for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
4119 				retval = hub_set_address(udev, devnum);
4120 				if (retval >= 0)
4121 					break;
4122 				msleep(200);
4123 			}
4124 			if (retval < 0) {
4125 				if (retval != -ENODEV)
4126 					dev_err(&udev->dev, "device not accepting address %d, error %d\n",
4127 							devnum, retval);
4128 				goto fail;
4129 			}
4130 			if (udev->speed == USB_SPEED_SUPER) {
4131 				devnum = udev->devnum;
4132 				dev_info(&udev->dev,
4133 						"%s SuperSpeed USB device number %d using %s\n",
4134 						(udev->config) ? "reset" : "new",
4135 						devnum, udev->bus->controller->driver->name);
4136 			}
4137 
4138 			/* cope with hardware quirkiness:
4139 			 *  - let SET_ADDRESS settle, some device hardware wants it
4140 			 *  - read ep0 maxpacket even for high and low speed,
4141 			 */
4142 			msleep(10);
4143 			if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3))
4144 				break;
4145   		}
4146 
4147 		retval = usb_get_device_descriptor(udev, 8);
4148 		if (retval < 8) {
4149 			if (retval != -ENODEV)
4150 				dev_err(&udev->dev,
4151 					"device descriptor read/8, error %d\n",
4152 					retval);
4153 			if (retval >= 0)
4154 				retval = -EMSGSIZE;
4155 		} else {
4156 			retval = 0;
4157 			break;
4158 		}
4159 	}
4160 	if (retval)
4161 		goto fail;
4162 
4163 	if (hcd->phy && !hdev->parent)
4164 		usb_phy_notify_connect(hcd->phy, udev->speed);
4165 
4166 	/*
4167 	 * Some superspeed devices have finished the link training process
4168 	 * and attached to a superspeed hub port, but the device descriptor
4169 	 * got from those devices show they aren't superspeed devices. Warm
4170 	 * reset the port attached by the devices can fix them.
4171 	 */
4172 	if ((udev->speed == USB_SPEED_SUPER) &&
4173 			(le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
4174 		dev_err(&udev->dev, "got a wrong device descriptor, "
4175 				"warm reset device\n");
4176 		hub_port_reset(hub, port1, udev,
4177 				HUB_BH_RESET_TIME, true);
4178 		retval = -EINVAL;
4179 		goto fail;
4180 	}
4181 
4182 	if (udev->descriptor.bMaxPacketSize0 == 0xff ||
4183 			udev->speed == USB_SPEED_SUPER)
4184 		i = 512;
4185 	else
4186 		i = udev->descriptor.bMaxPacketSize0;
4187 	if (usb_endpoint_maxp(&udev->ep0.desc) != i) {
4188 		if (udev->speed == USB_SPEED_LOW ||
4189 				!(i == 8 || i == 16 || i == 32 || i == 64)) {
4190 			dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i);
4191 			retval = -EMSGSIZE;
4192 			goto fail;
4193 		}
4194 		if (udev->speed == USB_SPEED_FULL)
4195 			dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
4196 		else
4197 			dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
4198 		udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
4199 		usb_ep0_reinit(udev);
4200 	}
4201 
4202 	retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
4203 	if (retval < (signed)sizeof(udev->descriptor)) {
4204 		if (retval != -ENODEV)
4205 			dev_err(&udev->dev, "device descriptor read/all, error %d\n",
4206 					retval);
4207 		if (retval >= 0)
4208 			retval = -ENOMSG;
4209 		goto fail;
4210 	}
4211 
4212 	if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
4213 		retval = usb_get_bos_descriptor(udev);
4214 		if (!retval) {
4215 			udev->lpm_capable = usb_device_supports_lpm(udev);
4216 			usb_set_lpm_parameters(udev);
4217 		}
4218 	}
4219 
4220 	retval = 0;
4221 	/* notify HCD that we have a device connected and addressed */
4222 	if (hcd->driver->update_device)
4223 		hcd->driver->update_device(hcd, udev);
4224 fail:
4225 	if (retval) {
4226 		hub_port_disable(hub, port1, 0);
4227 		update_devnum(udev, devnum);	/* for disconnect processing */
4228 	}
4229 	mutex_unlock(&usb_address0_mutex);
4230 	return retval;
4231 }
4232 
4233 static void
check_highspeed(struct usb_hub * hub,struct usb_device * udev,int port1)4234 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
4235 {
4236 	struct usb_qualifier_descriptor	*qual;
4237 	int				status;
4238 
4239 	qual = kmalloc (sizeof *qual, GFP_KERNEL);
4240 	if (qual == NULL)
4241 		return;
4242 
4243 	status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0,
4244 			qual, sizeof *qual);
4245 	if (status == sizeof *qual) {
4246 		dev_info(&udev->dev, "not running at top speed; "
4247 			"connect to a high speed hub\n");
4248 		/* hub LEDs are probably harder to miss than syslog */
4249 		if (hub->has_indicators) {
4250 			hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
4251 			schedule_delayed_work (&hub->leds, 0);
4252 		}
4253 	}
4254 	kfree(qual);
4255 }
4256 
4257 static unsigned
hub_power_remaining(struct usb_hub * hub)4258 hub_power_remaining (struct usb_hub *hub)
4259 {
4260 	struct usb_device *hdev = hub->hdev;
4261 	int remaining;
4262 	int port1;
4263 
4264 	if (!hub->limited_power)
4265 		return 0;
4266 
4267 	remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
4268 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
4269 		struct usb_device	*udev = hub->ports[port1 - 1]->child;
4270 		int			delta;
4271 		unsigned		unit_load;
4272 
4273 		if (!udev)
4274 			continue;
4275 		if (hub_is_superspeed(udev))
4276 			unit_load = 150;
4277 		else
4278 			unit_load = 100;
4279 
4280 		/*
4281 		 * Unconfigured devices may not use more than one unit load,
4282 		 * or 8mA for OTG ports
4283 		 */
4284 		if (udev->actconfig)
4285 			delta = usb_get_max_power(udev, udev->actconfig);
4286 		else if (port1 != udev->bus->otg_port || hdev->parent)
4287 			delta = unit_load;
4288 		else
4289 			delta = 8;
4290 		if (delta > hub->mA_per_port)
4291 			dev_warn(&udev->dev,
4292 				 "%dmA is over %umA budget for port %d!\n",
4293 				 delta, hub->mA_per_port, port1);
4294 		remaining -= delta;
4295 	}
4296 	if (remaining < 0) {
4297 		dev_warn(hub->intfdev, "%dmA over power budget!\n",
4298 			- remaining);
4299 		remaining = 0;
4300 	}
4301 	return remaining;
4302 }
4303 
4304 /* Handle physical or logical connection change events.
4305  * This routine is called when:
4306  * 	a port connection-change occurs;
4307  *	a port enable-change occurs (often caused by EMI);
4308  *	usb_reset_and_verify_device() encounters changed descriptors (as from
4309  *		a firmware download)
4310  * caller already locked the hub
4311  */
hub_port_connect_change(struct usb_hub * hub,int port1,u16 portstatus,u16 portchange)4312 static void hub_port_connect_change(struct usb_hub *hub, int port1,
4313 					u16 portstatus, u16 portchange)
4314 {
4315 	struct usb_device *hdev = hub->hdev;
4316 	struct device *hub_dev = hub->intfdev;
4317 	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
4318 	unsigned wHubCharacteristics =
4319 			le16_to_cpu(hub->descriptor->wHubCharacteristics);
4320 	struct usb_device *udev;
4321 	int status, i;
4322 	unsigned unit_load;
4323 
4324 	dev_dbg (hub_dev,
4325 		"port %d, status %04x, change %04x, %s\n",
4326 		port1, portstatus, portchange, portspeed(hub, portstatus));
4327 
4328 	if (hub->has_indicators) {
4329 		set_port_led(hub, port1, HUB_LED_AUTO);
4330 		hub->indicator[port1-1] = INDICATOR_AUTO;
4331 	}
4332 
4333 #ifdef	CONFIG_USB_OTG
4334 	/* during HNP, don't repeat the debounce */
4335 	if (hdev->bus->is_b_host)
4336 		portchange &= ~(USB_PORT_STAT_C_CONNECTION |
4337 				USB_PORT_STAT_C_ENABLE);
4338 #endif
4339 
4340 	/* Try to resuscitate an existing device */
4341 	udev = hub->ports[port1 - 1]->child;
4342 	if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
4343 			udev->state != USB_STATE_NOTATTACHED) {
4344 		usb_lock_device(udev);
4345 		if (portstatus & USB_PORT_STAT_ENABLE) {
4346 			status = 0;		/* Nothing to do */
4347 
4348 #ifdef CONFIG_PM_RUNTIME
4349 		} else if (udev->state == USB_STATE_SUSPENDED &&
4350 				udev->persist_enabled) {
4351 			/* For a suspended device, treat this as a
4352 			 * remote wakeup event.
4353 			 */
4354 			status = usb_remote_wakeup(udev);
4355 #endif
4356 
4357 		} else {
4358 			status = -ENODEV;	/* Don't resuscitate */
4359 		}
4360 		usb_unlock_device(udev);
4361 
4362 		if (status == 0) {
4363 			clear_bit(port1, hub->change_bits);
4364 			return;
4365 		}
4366 	}
4367 
4368 	/* Disconnect any existing devices under this port */
4369 	if (udev) {
4370 		if (hcd->phy && !hdev->parent &&
4371 				!(portstatus & USB_PORT_STAT_CONNECTION))
4372 			usb_phy_notify_disconnect(hcd->phy, udev->speed);
4373 		usb_disconnect(&hub->ports[port1 - 1]->child);
4374 	}
4375 	clear_bit(port1, hub->change_bits);
4376 
4377 	/* We can forget about a "removed" device when there's a physical
4378 	 * disconnect or the connect status changes.
4379 	 */
4380 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4381 			(portchange & USB_PORT_STAT_C_CONNECTION))
4382 		clear_bit(port1, hub->removed_bits);
4383 
4384 	if (portchange & (USB_PORT_STAT_C_CONNECTION |
4385 				USB_PORT_STAT_C_ENABLE)) {
4386 		status = hub_port_debounce_be_stable(hub, port1);
4387 		if (status < 0) {
4388 			if (status != -ENODEV && printk_ratelimit())
4389 				dev_err(hub_dev, "connect-debounce failed, "
4390 						"port %d disabled\n", port1);
4391 			portstatus &= ~USB_PORT_STAT_CONNECTION;
4392 		} else {
4393 			portstatus = status;
4394 		}
4395 	}
4396 
4397 	/* Return now if debouncing failed or nothing is connected or
4398 	 * the device was "removed".
4399 	 */
4400 	if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4401 			test_bit(port1, hub->removed_bits)) {
4402 
4403 		/* maybe switch power back on (e.g. root hub was reset) */
4404 		if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2
4405 				&& !port_is_power_on(hub, portstatus))
4406 			set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
4407 
4408 		if (portstatus & USB_PORT_STAT_ENABLE)
4409   			goto done;
4410 		return;
4411 	}
4412 	if (hub_is_superspeed(hub->hdev))
4413 		unit_load = 150;
4414 	else
4415 		unit_load = 100;
4416 
4417 	status = 0;
4418 	for (i = 0; i < SET_CONFIG_TRIES; i++) {
4419 
4420 		/* reallocate for each attempt, since references
4421 		 * to the previous one can escape in various ways
4422 		 */
4423 		udev = usb_alloc_dev(hdev, hdev->bus, port1);
4424 		if (!udev) {
4425 			dev_err (hub_dev,
4426 				"couldn't allocate port %d usb_device\n",
4427 				port1);
4428 			goto done;
4429 		}
4430 
4431 		usb_set_device_state(udev, USB_STATE_POWERED);
4432  		udev->bus_mA = hub->mA_per_port;
4433 		udev->level = hdev->level + 1;
4434 		udev->wusb = hub_is_wusb(hub);
4435 
4436 		/* Only USB 3.0 devices are connected to SuperSpeed hubs. */
4437 		if (hub_is_superspeed(hub->hdev))
4438 			udev->speed = USB_SPEED_SUPER;
4439 		else
4440 			udev->speed = USB_SPEED_UNKNOWN;
4441 
4442 		choose_devnum(udev);
4443 		if (udev->devnum <= 0) {
4444 			status = -ENOTCONN;	/* Don't retry */
4445 			goto loop;
4446 		}
4447 
4448 		/* reset (non-USB 3.0 devices) and get descriptor */
4449 		status = hub_port_init(hub, udev, port1, i);
4450 		if (status < 0)
4451 			goto loop;
4452 
4453 		usb_detect_quirks(udev);
4454 		if (udev->quirks & USB_QUIRK_DELAY_INIT)
4455 			msleep(1000);
4456 
4457 		/* consecutive bus-powered hubs aren't reliable; they can
4458 		 * violate the voltage drop budget.  if the new child has
4459 		 * a "powered" LED, users should notice we didn't enable it
4460 		 * (without reading syslog), even without per-port LEDs
4461 		 * on the parent.
4462 		 */
4463 		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
4464 				&& udev->bus_mA <= unit_load) {
4465 			u16	devstat;
4466 
4467 			status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
4468 					&devstat);
4469 			if (status < 2) {
4470 				dev_dbg(&udev->dev, "get status %d ?\n", status);
4471 				goto loop_disable;
4472 			}
4473 			le16_to_cpus(&devstat);
4474 			if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
4475 				dev_err(&udev->dev,
4476 					"can't connect bus-powered hub "
4477 					"to this port\n");
4478 				if (hub->has_indicators) {
4479 					hub->indicator[port1-1] =
4480 						INDICATOR_AMBER_BLINK;
4481 					schedule_delayed_work (&hub->leds, 0);
4482 				}
4483 				status = -ENOTCONN;	/* Don't retry */
4484 				goto loop_disable;
4485 			}
4486 		}
4487 
4488 		/* check for devices running slower than they could */
4489 		if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
4490 				&& udev->speed == USB_SPEED_FULL
4491 				&& highspeed_hubs != 0)
4492 			check_highspeed (hub, udev, port1);
4493 
4494 		/* Store the parent's children[] pointer.  At this point
4495 		 * udev becomes globally accessible, although presumably
4496 		 * no one will look at it until hdev is unlocked.
4497 		 */
4498 		status = 0;
4499 
4500 		/* We mustn't add new devices if the parent hub has
4501 		 * been disconnected; we would race with the
4502 		 * recursively_mark_NOTATTACHED() routine.
4503 		 */
4504 		spin_lock_irq(&device_state_lock);
4505 		if (hdev->state == USB_STATE_NOTATTACHED)
4506 			status = -ENOTCONN;
4507 		else
4508 			hub->ports[port1 - 1]->child = udev;
4509 		spin_unlock_irq(&device_state_lock);
4510 
4511 		/* Run it through the hoops (find a driver, etc) */
4512 		if (!status) {
4513 			status = usb_new_device(udev);
4514 			if (status) {
4515 				spin_lock_irq(&device_state_lock);
4516 				hub->ports[port1 - 1]->child = NULL;
4517 				spin_unlock_irq(&device_state_lock);
4518 			}
4519 		}
4520 
4521 		if (status)
4522 			goto loop_disable;
4523 
4524 		status = hub_power_remaining(hub);
4525 		if (status)
4526 			dev_dbg(hub_dev, "%dmA power budget left\n", status);
4527 
4528 		return;
4529 
4530 loop_disable:
4531 		hub_port_disable(hub, port1, 1);
4532 loop:
4533 		usb_ep0_reinit(udev);
4534 		release_devnum(udev);
4535 		hub_free_dev(udev);
4536 		usb_put_dev(udev);
4537 		if ((status == -ENOTCONN) || (status == -ENOTSUPP))
4538 			break;
4539 	}
4540 	if (hub->hdev->parent ||
4541 			!hcd->driver->port_handed_over ||
4542 			!(hcd->driver->port_handed_over)(hcd, port1)) {
4543 		if (status != -ENOTCONN && status != -ENODEV)
4544 			dev_err(hub_dev, "unable to enumerate USB device on port %d\n",
4545 					port1);
4546 	}
4547 
4548 done:
4549 	hub_port_disable(hub, port1, 1);
4550 	if (hcd->driver->relinquish_port && !hub->hdev->parent)
4551 		hcd->driver->relinquish_port(hcd, port1);
4552 }
4553 
4554 /* Returns 1 if there was a remote wakeup and a connect status change. */
hub_handle_remote_wakeup(struct usb_hub * hub,unsigned int port,u16 portstatus,u16 portchange)4555 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
4556 		u16 portstatus, u16 portchange)
4557 {
4558 	struct usb_device *hdev;
4559 	struct usb_device *udev;
4560 	int connect_change = 0;
4561 	int ret;
4562 
4563 	hdev = hub->hdev;
4564 	udev = hub->ports[port - 1]->child;
4565 	if (!hub_is_superspeed(hdev)) {
4566 		if (!(portchange & USB_PORT_STAT_C_SUSPEND))
4567 			return 0;
4568 		usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
4569 	} else {
4570 		if (!udev || udev->state != USB_STATE_SUSPENDED ||
4571 				 (portstatus & USB_PORT_STAT_LINK_STATE) !=
4572 				 USB_SS_PORT_LS_U0)
4573 			return 0;
4574 	}
4575 
4576 	if (udev) {
4577 		/* TRSMRCY = 10 msec */
4578 		msleep(10);
4579 
4580 		usb_lock_device(udev);
4581 		ret = usb_remote_wakeup(udev);
4582 		usb_unlock_device(udev);
4583 		if (ret < 0)
4584 			connect_change = 1;
4585 	} else {
4586 		ret = -ENODEV;
4587 		hub_port_disable(hub, port, 1);
4588 	}
4589 	dev_dbg(hub->intfdev, "resume on port %d, status %d\n",
4590 			port, ret);
4591 	return connect_change;
4592 }
4593 
hub_events(void)4594 static void hub_events(void)
4595 {
4596 	struct list_head *tmp;
4597 	struct usb_device *hdev;
4598 	struct usb_interface *intf;
4599 	struct usb_hub *hub;
4600 	struct device *hub_dev;
4601 	u16 hubstatus;
4602 	u16 hubchange;
4603 	u16 portstatus;
4604 	u16 portchange;
4605 	int i, ret;
4606 	int connect_change, wakeup_change;
4607 
4608 	/*
4609 	 *  We restart the list every time to avoid a deadlock with
4610 	 * deleting hubs downstream from this one. This should be
4611 	 * safe since we delete the hub from the event list.
4612 	 * Not the most efficient, but avoids deadlocks.
4613 	 */
4614 	while (1) {
4615 
4616 		/* Grab the first entry at the beginning of the list */
4617 		spin_lock_irq(&hub_event_lock);
4618 		if (list_empty(&hub_event_list)) {
4619 			spin_unlock_irq(&hub_event_lock);
4620 			break;
4621 		}
4622 
4623 		tmp = hub_event_list.next;
4624 		list_del_init(tmp);
4625 
4626 		hub = list_entry(tmp, struct usb_hub, event_list);
4627 		kref_get(&hub->kref);
4628 		spin_unlock_irq(&hub_event_lock);
4629 
4630 		hdev = hub->hdev;
4631 		hub_dev = hub->intfdev;
4632 		intf = to_usb_interface(hub_dev);
4633 		dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
4634 				hdev->state, hub->descriptor
4635 					? hub->descriptor->bNbrPorts
4636 					: 0,
4637 				/* NOTE: expects max 15 ports... */
4638 				(u16) hub->change_bits[0],
4639 				(u16) hub->event_bits[0]);
4640 
4641 		/* Lock the device, then check to see if we were
4642 		 * disconnected while waiting for the lock to succeed. */
4643 		usb_lock_device(hdev);
4644 		if (unlikely(hub->disconnected))
4645 			goto loop_disconnected;
4646 
4647 		/* If the hub has died, clean up after it */
4648 		if (hdev->state == USB_STATE_NOTATTACHED) {
4649 			hub->error = -ENODEV;
4650 			hub_quiesce(hub, HUB_DISCONNECT);
4651 			goto loop;
4652 		}
4653 
4654 		/* Autoresume */
4655 		ret = usb_autopm_get_interface(intf);
4656 		if (ret) {
4657 			dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
4658 			goto loop;
4659 		}
4660 
4661 		/* If this is an inactive hub, do nothing */
4662 		if (hub->quiescing)
4663 			goto loop_autopm;
4664 
4665 		if (hub->error) {
4666 			dev_dbg (hub_dev, "resetting for error %d\n",
4667 				hub->error);
4668 
4669 			ret = usb_reset_device(hdev);
4670 			if (ret) {
4671 				dev_dbg (hub_dev,
4672 					"error resetting hub: %d\n", ret);
4673 				goto loop_autopm;
4674 			}
4675 
4676 			hub->nerrors = 0;
4677 			hub->error = 0;
4678 		}
4679 
4680 		/* deal with port status changes */
4681 		for (i = 1; i <= hub->descriptor->bNbrPorts; i++) {
4682 			if (test_bit(i, hub->busy_bits))
4683 				continue;
4684 			connect_change = test_bit(i, hub->change_bits);
4685 			wakeup_change = test_and_clear_bit(i, hub->wakeup_bits);
4686 			if (!test_and_clear_bit(i, hub->event_bits) &&
4687 					!connect_change && !wakeup_change)
4688 				continue;
4689 
4690 			ret = hub_port_status(hub, i,
4691 					&portstatus, &portchange);
4692 			if (ret < 0)
4693 				continue;
4694 
4695 			if (portchange & USB_PORT_STAT_C_CONNECTION) {
4696 				usb_clear_port_feature(hdev, i,
4697 					USB_PORT_FEAT_C_CONNECTION);
4698 				connect_change = 1;
4699 			}
4700 
4701 			if (portchange & USB_PORT_STAT_C_ENABLE) {
4702 				if (!connect_change)
4703 					dev_dbg (hub_dev,
4704 						"port %d enable change, "
4705 						"status %08x\n",
4706 						i, portstatus);
4707 				usb_clear_port_feature(hdev, i,
4708 					USB_PORT_FEAT_C_ENABLE);
4709 
4710 				/*
4711 				 * EM interference sometimes causes badly
4712 				 * shielded USB devices to be shutdown by
4713 				 * the hub, this hack enables them again.
4714 				 * Works at least with mouse driver.
4715 				 */
4716 				if (!(portstatus & USB_PORT_STAT_ENABLE)
4717 				    && !connect_change
4718 				    && hub->ports[i - 1]->child) {
4719 					dev_err (hub_dev,
4720 					    "port %i "
4721 					    "disabled by hub (EMI?), "
4722 					    "re-enabling...\n",
4723 						i);
4724 					connect_change = 1;
4725 				}
4726 			}
4727 
4728 			if (hub_handle_remote_wakeup(hub, i,
4729 						portstatus, portchange))
4730 				connect_change = 1;
4731 
4732 			if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
4733 				u16 status = 0;
4734 				u16 unused;
4735 
4736 				dev_dbg(hub_dev, "over-current change on port "
4737 					"%d\n", i);
4738 				usb_clear_port_feature(hdev, i,
4739 					USB_PORT_FEAT_C_OVER_CURRENT);
4740 				msleep(100);	/* Cool down */
4741 				hub_power_on(hub, true);
4742 				hub_port_status(hub, i, &status, &unused);
4743 				if (status & USB_PORT_STAT_OVERCURRENT)
4744 					dev_err(hub_dev, "over-current "
4745 						"condition on port %d\n", i);
4746 			}
4747 
4748 			if (portchange & USB_PORT_STAT_C_RESET) {
4749 				dev_dbg (hub_dev,
4750 					"reset change on port %d\n",
4751 					i);
4752 				usb_clear_port_feature(hdev, i,
4753 					USB_PORT_FEAT_C_RESET);
4754 			}
4755 			if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
4756 					hub_is_superspeed(hub->hdev)) {
4757 				dev_dbg(hub_dev,
4758 					"warm reset change on port %d\n",
4759 					i);
4760 				usb_clear_port_feature(hdev, i,
4761 					USB_PORT_FEAT_C_BH_PORT_RESET);
4762 			}
4763 			if (portchange & USB_PORT_STAT_C_LINK_STATE) {
4764 				usb_clear_port_feature(hub->hdev, i,
4765 						USB_PORT_FEAT_C_PORT_LINK_STATE);
4766 			}
4767 			if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) {
4768 				dev_warn(hub_dev,
4769 					"config error on port %d\n",
4770 					i);
4771 				usb_clear_port_feature(hub->hdev, i,
4772 						USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
4773 			}
4774 
4775 			/* Warm reset a USB3 protocol port if it's in
4776 			 * SS.Inactive state.
4777 			 */
4778 			if (hub_port_warm_reset_required(hub, portstatus)) {
4779 				int status;
4780 				struct usb_device *udev =
4781 					hub->ports[i - 1]->child;
4782 
4783 				dev_dbg(hub_dev, "warm reset port %d\n", i);
4784 				if (!udev) {
4785 					status = hub_port_reset(hub, i,
4786 							NULL, HUB_BH_RESET_TIME,
4787 							true);
4788 					if (status < 0)
4789 						hub_port_disable(hub, i, 1);
4790 				} else {
4791 					usb_lock_device(udev);
4792 					status = usb_reset_device(udev);
4793 					usb_unlock_device(udev);
4794 				}
4795 				connect_change = 0;
4796 			}
4797 
4798 			if (connect_change)
4799 				hub_port_connect_change(hub, i,
4800 						portstatus, portchange);
4801 		} /* end for i */
4802 
4803 		/* deal with hub status changes */
4804 		if (test_and_clear_bit(0, hub->event_bits) == 0)
4805 			;	/* do nothing */
4806 		else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
4807 			dev_err (hub_dev, "get_hub_status failed\n");
4808 		else {
4809 			if (hubchange & HUB_CHANGE_LOCAL_POWER) {
4810 				dev_dbg (hub_dev, "power change\n");
4811 				clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
4812 				if (hubstatus & HUB_STATUS_LOCAL_POWER)
4813 					/* FIXME: Is this always true? */
4814 					hub->limited_power = 1;
4815 				else
4816 					hub->limited_power = 0;
4817 			}
4818 			if (hubchange & HUB_CHANGE_OVERCURRENT) {
4819 				u16 status = 0;
4820 				u16 unused;
4821 
4822 				dev_dbg(hub_dev, "over-current change\n");
4823 				clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
4824 				msleep(500);	/* Cool down */
4825                         	hub_power_on(hub, true);
4826 				hub_hub_status(hub, &status, &unused);
4827 				if (status & HUB_STATUS_OVERCURRENT)
4828 					dev_err(hub_dev, "over-current "
4829 						"condition\n");
4830 			}
4831 		}
4832 
4833  loop_autopm:
4834 		/* Balance the usb_autopm_get_interface() above */
4835 		usb_autopm_put_interface_no_suspend(intf);
4836  loop:
4837 		/* Balance the usb_autopm_get_interface_no_resume() in
4838 		 * kick_khubd() and allow autosuspend.
4839 		 */
4840 		usb_autopm_put_interface(intf);
4841  loop_disconnected:
4842 		usb_unlock_device(hdev);
4843 		kref_put(&hub->kref, hub_release);
4844 
4845         } /* end while (1) */
4846 }
4847 
hub_thread(void * __unused)4848 static int hub_thread(void *__unused)
4849 {
4850 	/* khubd needs to be freezable to avoid intefering with USB-PERSIST
4851 	 * port handover.  Otherwise it might see that a full-speed device
4852 	 * was gone before the EHCI controller had handed its port over to
4853 	 * the companion full-speed controller.
4854 	 */
4855 	set_freezable();
4856 
4857 	do {
4858 		hub_events();
4859 		wait_event_freezable(khubd_wait,
4860 				!list_empty(&hub_event_list) ||
4861 				kthread_should_stop());
4862 	} while (!kthread_should_stop() || !list_empty(&hub_event_list));
4863 
4864 	pr_debug("%s: khubd exiting\n", usbcore_name);
4865 	return 0;
4866 }
4867 
4868 static const struct usb_device_id hub_id_table[] = {
4869     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
4870 	           | USB_DEVICE_ID_MATCH_INT_CLASS,
4871       .idVendor = USB_VENDOR_GENESYS_LOGIC,
4872       .bInterfaceClass = USB_CLASS_HUB,
4873       .driver_info = HUB_QUIRK_CHECK_PORT_AUTOSUSPEND},
4874     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
4875       .bDeviceClass = USB_CLASS_HUB},
4876     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
4877       .bInterfaceClass = USB_CLASS_HUB},
4878     { }						/* Terminating entry */
4879 };
4880 
4881 MODULE_DEVICE_TABLE (usb, hub_id_table);
4882 
4883 static struct usb_driver hub_driver = {
4884 	.name =		"hub",
4885 	.probe =	hub_probe,
4886 	.disconnect =	hub_disconnect,
4887 	.suspend =	hub_suspend,
4888 	.resume =	hub_resume,
4889 	.reset_resume =	hub_reset_resume,
4890 	.pre_reset =	hub_pre_reset,
4891 	.post_reset =	hub_post_reset,
4892 	.unlocked_ioctl = hub_ioctl,
4893 	.id_table =	hub_id_table,
4894 	.supports_autosuspend =	1,
4895 };
4896 
usb_hub_init(void)4897 int usb_hub_init(void)
4898 {
4899 	if (usb_register(&hub_driver) < 0) {
4900 		printk(KERN_ERR "%s: can't register hub driver\n",
4901 			usbcore_name);
4902 		return -1;
4903 	}
4904 
4905 	khubd_task = kthread_run(hub_thread, NULL, "khubd");
4906 	if (!IS_ERR(khubd_task))
4907 		return 0;
4908 
4909 	/* Fall through if kernel_thread failed */
4910 	usb_deregister(&hub_driver);
4911 	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);
4912 
4913 	return -1;
4914 }
4915 
usb_hub_cleanup(void)4916 void usb_hub_cleanup(void)
4917 {
4918 	kthread_stop(khubd_task);
4919 
4920 	/*
4921 	 * Hub resources are freed for us by usb_deregister. It calls
4922 	 * usb_driver_purge on every device which in turn calls that
4923 	 * devices disconnect function if it is using this driver.
4924 	 * The hub_disconnect function takes care of releasing the
4925 	 * individual hub resources. -greg
4926 	 */
4927 	usb_deregister(&hub_driver);
4928 } /* usb_hub_cleanup() */
4929 
descriptors_changed(struct usb_device * udev,struct usb_device_descriptor * old_device_descriptor)4930 static int descriptors_changed(struct usb_device *udev,
4931 		struct usb_device_descriptor *old_device_descriptor)
4932 {
4933 	int		changed = 0;
4934 	unsigned	index;
4935 	unsigned	serial_len = 0;
4936 	unsigned	len;
4937 	unsigned	old_length;
4938 	int		length;
4939 	char		*buf;
4940 
4941 	if (memcmp(&udev->descriptor, old_device_descriptor,
4942 			sizeof(*old_device_descriptor)) != 0)
4943 		return 1;
4944 
4945 	/* Since the idVendor, idProduct, and bcdDevice values in the
4946 	 * device descriptor haven't changed, we will assume the
4947 	 * Manufacturer and Product strings haven't changed either.
4948 	 * But the SerialNumber string could be different (e.g., a
4949 	 * different flash card of the same brand).
4950 	 */
4951 	if (udev->serial)
4952 		serial_len = strlen(udev->serial) + 1;
4953 
4954 	len = serial_len;
4955 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
4956 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
4957 		len = max(len, old_length);
4958 	}
4959 
4960 	buf = kmalloc(len, GFP_NOIO);
4961 	if (buf == NULL) {
4962 		dev_err(&udev->dev, "no mem to re-read configs after reset\n");
4963 		/* assume the worst */
4964 		return 1;
4965 	}
4966 	for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
4967 		old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
4968 		length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
4969 				old_length);
4970 		if (length != old_length) {
4971 			dev_dbg(&udev->dev, "config index %d, error %d\n",
4972 					index, length);
4973 			changed = 1;
4974 			break;
4975 		}
4976 		if (memcmp (buf, udev->rawdescriptors[index], old_length)
4977 				!= 0) {
4978 			dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
4979 				index,
4980 				((struct usb_config_descriptor *) buf)->
4981 					bConfigurationValue);
4982 			changed = 1;
4983 			break;
4984 		}
4985 	}
4986 
4987 	if (!changed && serial_len) {
4988 		length = usb_string(udev, udev->descriptor.iSerialNumber,
4989 				buf, serial_len);
4990 		if (length + 1 != serial_len) {
4991 			dev_dbg(&udev->dev, "serial string error %d\n",
4992 					length);
4993 			changed = 1;
4994 		} else if (memcmp(buf, udev->serial, length) != 0) {
4995 			dev_dbg(&udev->dev, "serial string changed\n");
4996 			changed = 1;
4997 		}
4998 	}
4999 
5000 	kfree(buf);
5001 	return changed;
5002 }
5003 
5004 /**
5005  * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
5006  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5007  *
5008  * WARNING - don't use this routine to reset a composite device
5009  * (one with multiple interfaces owned by separate drivers)!
5010  * Use usb_reset_device() instead.
5011  *
5012  * Do a port reset, reassign the device's address, and establish its
5013  * former operating configuration.  If the reset fails, or the device's
5014  * descriptors change from their values before the reset, or the original
5015  * configuration and altsettings cannot be restored, a flag will be set
5016  * telling khubd to pretend the device has been disconnected and then
5017  * re-connected.  All drivers will be unbound, and the device will be
5018  * re-enumerated and probed all over again.
5019  *
5020  * Returns 0 if the reset succeeded, -ENODEV if the device has been
5021  * flagged for logical disconnection, or some other negative error code
5022  * if the reset wasn't even attempted.
5023  *
5024  * The caller must own the device lock.  For example, it's safe to use
5025  * this from a driver probe() routine after downloading new firmware.
5026  * For calls that might not occur during probe(), drivers should lock
5027  * the device using usb_lock_device_for_reset().
5028  *
5029  * Locking exception: This routine may also be called from within an
5030  * autoresume handler.  Such usage won't conflict with other tasks
5031  * holding the device lock because these tasks should always call
5032  * usb_autopm_resume_device(), thereby preventing any unwanted autoresume.
5033  */
usb_reset_and_verify_device(struct usb_device * udev)5034 static int usb_reset_and_verify_device(struct usb_device *udev)
5035 {
5036 	struct usb_device		*parent_hdev = udev->parent;
5037 	struct usb_hub			*parent_hub;
5038 	struct usb_hcd			*hcd = bus_to_hcd(udev->bus);
5039 	struct usb_device_descriptor	descriptor = udev->descriptor;
5040 	int 				i, ret = 0;
5041 	int				port1 = udev->portnum;
5042 
5043 	if (udev->state == USB_STATE_NOTATTACHED ||
5044 			udev->state == USB_STATE_SUSPENDED) {
5045 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5046 				udev->state);
5047 		return -EINVAL;
5048 	}
5049 
5050 	if (!parent_hdev) {
5051 		/* this requires hcd-specific logic; see ohci_restart() */
5052 		dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
5053 		return -EISDIR;
5054 	}
5055 	parent_hub = usb_hub_to_struct_hub(parent_hdev);
5056 
5057 	/* Disable LPM and LTM while we reset the device and reinstall the alt
5058 	 * settings.  Device-initiated LPM settings, and system exit latency
5059 	 * settings are cleared when the device is reset, so we have to set
5060 	 * them up again.
5061 	 */
5062 	ret = usb_unlocked_disable_lpm(udev);
5063 	if (ret) {
5064 		dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
5065 		goto re_enumerate;
5066 	}
5067 	ret = usb_disable_ltm(udev);
5068 	if (ret) {
5069 		dev_err(&udev->dev, "%s Failed to disable LTM\n.",
5070 				__func__);
5071 		goto re_enumerate;
5072 	}
5073 
5074 	set_bit(port1, parent_hub->busy_bits);
5075 	for (i = 0; i < SET_CONFIG_TRIES; ++i) {
5076 
5077 		/* ep0 maxpacket size may change; let the HCD know about it.
5078 		 * Other endpoints will be handled by re-enumeration. */
5079 		usb_ep0_reinit(udev);
5080 		ret = hub_port_init(parent_hub, udev, port1, i);
5081 		if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
5082 			break;
5083 	}
5084 	clear_bit(port1, parent_hub->busy_bits);
5085 
5086 	if (ret < 0)
5087 		goto re_enumerate;
5088 
5089 	/* Device might have changed firmware (DFU or similar) */
5090 	if (descriptors_changed(udev, &descriptor)) {
5091 		dev_info(&udev->dev, "device firmware changed\n");
5092 		udev->descriptor = descriptor;	/* for disconnect() calls */
5093 		goto re_enumerate;
5094   	}
5095 
5096 	/* Restore the device's previous configuration */
5097 	if (!udev->actconfig)
5098 		goto done;
5099 
5100 	mutex_lock(hcd->bandwidth_mutex);
5101 	ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
5102 	if (ret < 0) {
5103 		dev_warn(&udev->dev,
5104 				"Busted HC?  Not enough HCD resources for "
5105 				"old configuration.\n");
5106 		mutex_unlock(hcd->bandwidth_mutex);
5107 		goto re_enumerate;
5108 	}
5109 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
5110 			USB_REQ_SET_CONFIGURATION, 0,
5111 			udev->actconfig->desc.bConfigurationValue, 0,
5112 			NULL, 0, USB_CTRL_SET_TIMEOUT);
5113 	if (ret < 0) {
5114 		dev_err(&udev->dev,
5115 			"can't restore configuration #%d (error=%d)\n",
5116 			udev->actconfig->desc.bConfigurationValue, ret);
5117 		mutex_unlock(hcd->bandwidth_mutex);
5118 		goto re_enumerate;
5119   	}
5120 	mutex_unlock(hcd->bandwidth_mutex);
5121 	usb_set_device_state(udev, USB_STATE_CONFIGURED);
5122 
5123 	/* Put interfaces back into the same altsettings as before.
5124 	 * Don't bother to send the Set-Interface request for interfaces
5125 	 * that were already in altsetting 0; besides being unnecessary,
5126 	 * many devices can't handle it.  Instead just reset the host-side
5127 	 * endpoint state.
5128 	 */
5129 	for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
5130 		struct usb_host_config *config = udev->actconfig;
5131 		struct usb_interface *intf = config->interface[i];
5132 		struct usb_interface_descriptor *desc;
5133 
5134 		desc = &intf->cur_altsetting->desc;
5135 		if (desc->bAlternateSetting == 0) {
5136 			usb_disable_interface(udev, intf, true);
5137 			usb_enable_interface(udev, intf, true);
5138 			ret = 0;
5139 		} else {
5140 			/* Let the bandwidth allocation function know that this
5141 			 * device has been reset, and it will have to use
5142 			 * alternate setting 0 as the current alternate setting.
5143 			 */
5144 			intf->resetting_device = 1;
5145 			ret = usb_set_interface(udev, desc->bInterfaceNumber,
5146 					desc->bAlternateSetting);
5147 			intf->resetting_device = 0;
5148 		}
5149 		if (ret < 0) {
5150 			dev_err(&udev->dev, "failed to restore interface %d "
5151 				"altsetting %d (error=%d)\n",
5152 				desc->bInterfaceNumber,
5153 				desc->bAlternateSetting,
5154 				ret);
5155 			goto re_enumerate;
5156 		}
5157 	}
5158 
5159 done:
5160 	/* Now that the alt settings are re-installed, enable LTM and LPM. */
5161 	usb_unlocked_enable_lpm(udev);
5162 	usb_enable_ltm(udev);
5163 	return 0;
5164 
5165 re_enumerate:
5166 	/* LPM state doesn't matter when we're about to destroy the device. */
5167 	hub_port_logical_disconnect(parent_hub, port1);
5168 	return -ENODEV;
5169 }
5170 
5171 /**
5172  * usb_reset_device - warn interface drivers and perform a USB port reset
5173  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5174  *
5175  * Warns all drivers bound to registered interfaces (using their pre_reset
5176  * method), performs the port reset, and then lets the drivers know that
5177  * the reset is over (using their post_reset method).
5178  *
5179  * Return value is the same as for usb_reset_and_verify_device().
5180  *
5181  * The caller must own the device lock.  For example, it's safe to use
5182  * this from a driver probe() routine after downloading new firmware.
5183  * For calls that might not occur during probe(), drivers should lock
5184  * the device using usb_lock_device_for_reset().
5185  *
5186  * If an interface is currently being probed or disconnected, we assume
5187  * its driver knows how to handle resets.  For all other interfaces,
5188  * if the driver doesn't have pre_reset and post_reset methods then
5189  * we attempt to unbind it and rebind afterward.
5190  */
usb_reset_device(struct usb_device * udev)5191 int usb_reset_device(struct usb_device *udev)
5192 {
5193 	int ret;
5194 	int i;
5195 	unsigned int noio_flag;
5196 	struct usb_host_config *config = udev->actconfig;
5197 
5198 	if (udev->state == USB_STATE_NOTATTACHED ||
5199 			udev->state == USB_STATE_SUSPENDED) {
5200 		dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5201 				udev->state);
5202 		return -EINVAL;
5203 	}
5204 
5205 	/*
5206 	 * Don't allocate memory with GFP_KERNEL in current
5207 	 * context to avoid possible deadlock if usb mass
5208 	 * storage interface or usbnet interface(iSCSI case)
5209 	 * is included in current configuration. The easist
5210 	 * approach is to do it for every device reset,
5211 	 * because the device 'memalloc_noio' flag may have
5212 	 * not been set before reseting the usb device.
5213 	 */
5214 	noio_flag = memalloc_noio_save();
5215 
5216 	/* Prevent autosuspend during the reset */
5217 	usb_autoresume_device(udev);
5218 
5219 	if (config) {
5220 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
5221 			struct usb_interface *cintf = config->interface[i];
5222 			struct usb_driver *drv;
5223 			int unbind = 0;
5224 
5225 			if (cintf->dev.driver) {
5226 				drv = to_usb_driver(cintf->dev.driver);
5227 				if (drv->pre_reset && drv->post_reset)
5228 					unbind = (drv->pre_reset)(cintf);
5229 				else if (cintf->condition ==
5230 						USB_INTERFACE_BOUND)
5231 					unbind = 1;
5232 				if (unbind)
5233 					usb_forced_unbind_intf(cintf);
5234 			}
5235 		}
5236 	}
5237 
5238 	ret = usb_reset_and_verify_device(udev);
5239 
5240 	if (config) {
5241 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
5242 			struct usb_interface *cintf = config->interface[i];
5243 			struct usb_driver *drv;
5244 			int rebind = cintf->needs_binding;
5245 
5246 			if (!rebind && cintf->dev.driver) {
5247 				drv = to_usb_driver(cintf->dev.driver);
5248 				if (drv->post_reset)
5249 					rebind = (drv->post_reset)(cintf);
5250 				else if (cintf->condition ==
5251 						USB_INTERFACE_BOUND)
5252 					rebind = 1;
5253 			}
5254 			if (ret == 0 && rebind)
5255 				usb_rebind_intf(cintf);
5256 		}
5257 	}
5258 
5259 	usb_autosuspend_device(udev);
5260 	memalloc_noio_restore(noio_flag);
5261 	return ret;
5262 }
5263 EXPORT_SYMBOL_GPL(usb_reset_device);
5264 
5265 
5266 /**
5267  * usb_queue_reset_device - Reset a USB device from an atomic context
5268  * @iface: USB interface belonging to the device to reset
5269  *
5270  * This function can be used to reset a USB device from an atomic
5271  * context, where usb_reset_device() won't work (as it blocks).
5272  *
5273  * Doing a reset via this method is functionally equivalent to calling
5274  * usb_reset_device(), except for the fact that it is delayed to a
5275  * workqueue. This means that any drivers bound to other interfaces
5276  * might be unbound, as well as users from usbfs in user space.
5277  *
5278  * Corner cases:
5279  *
5280  * - Scheduling two resets at the same time from two different drivers
5281  *   attached to two different interfaces of the same device is
5282  *   possible; depending on how the driver attached to each interface
5283  *   handles ->pre_reset(), the second reset might happen or not.
5284  *
5285  * - If a driver is unbound and it had a pending reset, the reset will
5286  *   be cancelled.
5287  *
5288  * - This function can be called during .probe() or .disconnect()
5289  *   times. On return from .disconnect(), any pending resets will be
5290  *   cancelled.
5291  *
5292  * There is no no need to lock/unlock the @reset_ws as schedule_work()
5293  * does its own.
5294  *
5295  * NOTE: We don't do any reference count tracking because it is not
5296  *     needed. The lifecycle of the work_struct is tied to the
5297  *     usb_interface. Before destroying the interface we cancel the
5298  *     work_struct, so the fact that work_struct is queued and or
5299  *     running means the interface (and thus, the device) exist and
5300  *     are referenced.
5301  */
usb_queue_reset_device(struct usb_interface * iface)5302 void usb_queue_reset_device(struct usb_interface *iface)
5303 {
5304 	schedule_work(&iface->reset_ws);
5305 }
5306 EXPORT_SYMBOL_GPL(usb_queue_reset_device);
5307 
5308 /**
5309  * usb_hub_find_child - Get the pointer of child device
5310  * attached to the port which is specified by @port1.
5311  * @hdev: USB device belonging to the usb hub
5312  * @port1: port num to indicate which port the child device
5313  *	is attached to.
5314  *
5315  * USB drivers call this function to get hub's child device
5316  * pointer.
5317  *
5318  * Return NULL if input param is invalid and
5319  * child's usb_device pointer if non-NULL.
5320  */
usb_hub_find_child(struct usb_device * hdev,int port1)5321 struct usb_device *usb_hub_find_child(struct usb_device *hdev,
5322 		int port1)
5323 {
5324 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5325 
5326 	if (port1 < 1 || port1 > hdev->maxchild)
5327 		return NULL;
5328 	return hub->ports[port1 - 1]->child;
5329 }
5330 EXPORT_SYMBOL_GPL(usb_hub_find_child);
5331 
5332 /**
5333  * usb_set_hub_port_connect_type - set hub port connect type.
5334  * @hdev: USB device belonging to the usb hub
5335  * @port1: port num of the port
5336  * @type: connect type of the port
5337  */
usb_set_hub_port_connect_type(struct usb_device * hdev,int port1,enum usb_port_connect_type type)5338 void usb_set_hub_port_connect_type(struct usb_device *hdev, int port1,
5339 	enum usb_port_connect_type type)
5340 {
5341 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5342 
5343 	hub->ports[port1 - 1]->connect_type = type;
5344 }
5345 
5346 /**
5347  * usb_get_hub_port_connect_type - Get the port's connect type
5348  * @hdev: USB device belonging to the usb hub
5349  * @port1: port num of the port
5350  *
5351  * Return connect type of the port and if input params are
5352  * invalid, return USB_PORT_CONNECT_TYPE_UNKNOWN.
5353  */
5354 enum usb_port_connect_type
usb_get_hub_port_connect_type(struct usb_device * hdev,int port1)5355 usb_get_hub_port_connect_type(struct usb_device *hdev, int port1)
5356 {
5357 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5358 
5359 	return hub->ports[port1 - 1]->connect_type;
5360 }
5361 
usb_hub_adjust_deviceremovable(struct usb_device * hdev,struct usb_hub_descriptor * desc)5362 void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
5363 		struct usb_hub_descriptor *desc)
5364 {
5365 	enum usb_port_connect_type connect_type;
5366 	int i;
5367 
5368 	if (!hub_is_superspeed(hdev)) {
5369 		for (i = 1; i <= hdev->maxchild; i++) {
5370 			connect_type = usb_get_hub_port_connect_type(hdev, i);
5371 
5372 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5373 				u8 mask = 1 << (i%8);
5374 
5375 				if (!(desc->u.hs.DeviceRemovable[i/8] & mask)) {
5376 					dev_dbg(&hdev->dev, "usb port%d's DeviceRemovable is changed to 1 according to platform information.\n",
5377 						i);
5378 					desc->u.hs.DeviceRemovable[i/8]	|= mask;
5379 				}
5380 			}
5381 		}
5382 	} else {
5383 		u16 port_removable = le16_to_cpu(desc->u.ss.DeviceRemovable);
5384 
5385 		for (i = 1; i <= hdev->maxchild; i++) {
5386 			connect_type = usb_get_hub_port_connect_type(hdev, i);
5387 
5388 			if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5389 				u16 mask = 1 << i;
5390 
5391 				if (!(port_removable & mask)) {
5392 					dev_dbg(&hdev->dev, "usb port%d's DeviceRemovable is changed to 1 according to platform information.\n",
5393 						i);
5394 					port_removable |= mask;
5395 				}
5396 			}
5397 		}
5398 
5399 		desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
5400 	}
5401 }
5402 
5403 #ifdef CONFIG_ACPI
5404 /**
5405  * usb_get_hub_port_acpi_handle - Get the usb port's acpi handle
5406  * @hdev: USB device belonging to the usb hub
5407  * @port1: port num of the port
5408  *
5409  * Return port's acpi handle if successful, NULL if params are
5410  * invaild.
5411  */
usb_get_hub_port_acpi_handle(struct usb_device * hdev,int port1)5412 acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
5413 	int port1)
5414 {
5415 	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5416 
5417 	return DEVICE_ACPI_HANDLE(&hub->ports[port1 - 1]->dev);
5418 }
5419 #endif
5420