1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Clock domain and sample rate management functions
4 */
5
6 #include <linux/bitops.h>
7 #include <linux/init.h>
8 #include <linux/string.h>
9 #include <linux/usb.h>
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
12 #include <linux/usb/audio-v3.h>
13
14 #include <sound/core.h>
15 #include <sound/info.h>
16 #include <sound/pcm.h>
17
18 #include "usbaudio.h"
19 #include "card.h"
20 #include "helper.h"
21 #include "clock.h"
22 #include "quirks.h"
23
find_uac_clock_desc(struct usb_host_interface * iface,int id,bool (* validator)(void *,int),u8 type)24 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
25 bool (*validator)(void *, int), u8 type)
26 {
27 void *cs = NULL;
28
29 while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
30 cs, type))) {
31 if (validator(cs, id))
32 return cs;
33 }
34
35 return NULL;
36 }
37
validate_clock_source_v2(void * p,int id)38 static bool validate_clock_source_v2(void *p, int id)
39 {
40 struct uac_clock_source_descriptor *cs = p;
41 return cs->bClockID == id;
42 }
43
validate_clock_source_v3(void * p,int id)44 static bool validate_clock_source_v3(void *p, int id)
45 {
46 struct uac3_clock_source_descriptor *cs = p;
47 return cs->bClockID == id;
48 }
49
validate_clock_selector_v2(void * p,int id)50 static bool validate_clock_selector_v2(void *p, int id)
51 {
52 struct uac_clock_selector_descriptor *cs = p;
53 return cs->bClockID == id;
54 }
55
validate_clock_selector_v3(void * p,int id)56 static bool validate_clock_selector_v3(void *p, int id)
57 {
58 struct uac3_clock_selector_descriptor *cs = p;
59 return cs->bClockID == id;
60 }
61
validate_clock_multiplier_v2(void * p,int id)62 static bool validate_clock_multiplier_v2(void *p, int id)
63 {
64 struct uac_clock_multiplier_descriptor *cs = p;
65 return cs->bClockID == id;
66 }
67
validate_clock_multiplier_v3(void * p,int id)68 static bool validate_clock_multiplier_v3(void *p, int id)
69 {
70 struct uac3_clock_multiplier_descriptor *cs = p;
71 return cs->bClockID == id;
72 }
73
74 #define DEFINE_FIND_HELPER(name, obj, validator, type) \
75 static obj *name(struct usb_host_interface *iface, int id) \
76 { \
77 return find_uac_clock_desc(iface, id, validator, type); \
78 }
79
80 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
81 struct uac_clock_source_descriptor,
82 validate_clock_source_v2, UAC2_CLOCK_SOURCE);
83 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
84 struct uac3_clock_source_descriptor,
85 validate_clock_source_v3, UAC3_CLOCK_SOURCE);
86
87 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
88 struct uac_clock_selector_descriptor,
89 validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
90 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
91 struct uac3_clock_selector_descriptor,
92 validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
93
94 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
95 struct uac_clock_multiplier_descriptor,
96 validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
97 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
98 struct uac3_clock_multiplier_descriptor,
99 validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
100
uac_clock_selector_get_val(struct snd_usb_audio * chip,int selector_id)101 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
102 {
103 unsigned char buf;
104 int ret;
105
106 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
107 UAC2_CS_CUR,
108 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
109 UAC2_CX_CLOCK_SELECTOR << 8,
110 snd_usb_ctrl_intf(chip) | (selector_id << 8),
111 &buf, sizeof(buf));
112
113 if (ret < 0)
114 return ret;
115
116 return buf;
117 }
118
uac_clock_selector_set_val(struct snd_usb_audio * chip,int selector_id,unsigned char pin)119 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
120 unsigned char pin)
121 {
122 int ret;
123
124 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
125 UAC2_CS_CUR,
126 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
127 UAC2_CX_CLOCK_SELECTOR << 8,
128 snd_usb_ctrl_intf(chip) | (selector_id << 8),
129 &pin, sizeof(pin));
130 if (ret < 0)
131 return ret;
132
133 if (ret != sizeof(pin)) {
134 usb_audio_err(chip,
135 "setting selector (id %d) unexpected length %d\n",
136 selector_id, ret);
137 return -EINVAL;
138 }
139
140 ret = uac_clock_selector_get_val(chip, selector_id);
141 if (ret < 0)
142 return ret;
143
144 if (ret != pin) {
145 usb_audio_err(chip,
146 "setting selector (id %d) to %x failed (current: %d)\n",
147 selector_id, pin, ret);
148 return -EINVAL;
149 }
150
151 return ret;
152 }
153
uac_clock_source_is_valid_quirk(struct snd_usb_audio * chip,struct audioformat * fmt,int source_id)154 static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
155 struct audioformat *fmt,
156 int source_id)
157 {
158 bool ret = false;
159 int count;
160 unsigned char data;
161 struct usb_device *dev = chip->dev;
162
163 if (fmt->protocol == UAC_VERSION_2) {
164 struct uac_clock_source_descriptor *cs_desc =
165 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
166
167 if (!cs_desc)
168 return false;
169
170 /*
171 * Assume the clock is valid if clock source supports only one
172 * single sample rate, the terminal is connected directly to it
173 * (there is no clock selector) and clock type is internal.
174 * This is to deal with some Denon DJ controllers that always
175 * reports that clock is invalid.
176 */
177 if (fmt->nr_rates == 1 &&
178 (fmt->clock & 0xff) == cs_desc->bClockID &&
179 (cs_desc->bmAttributes & 0x3) !=
180 UAC_CLOCK_SOURCE_TYPE_EXT)
181 return true;
182 }
183
184 /*
185 * MOTU MicroBook IIc
186 * Sample rate changes takes more than 2 seconds for this device. Clock
187 * validity request returns false during that period.
188 */
189 if (chip->usb_id == USB_ID(0x07fd, 0x0004)) {
190 count = 0;
191
192 while ((!ret) && (count < 50)) {
193 int err;
194
195 msleep(100);
196
197 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
198 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
199 UAC2_CS_CONTROL_CLOCK_VALID << 8,
200 snd_usb_ctrl_intf(chip) | (source_id << 8),
201 &data, sizeof(data));
202 if (err < 0) {
203 dev_warn(&dev->dev,
204 "%s(): cannot get clock validity for id %d\n",
205 __func__, source_id);
206 return false;
207 }
208
209 ret = !!data;
210 count++;
211 }
212 }
213
214 return ret;
215 }
216
uac_clock_source_is_valid(struct snd_usb_audio * chip,struct audioformat * fmt,int source_id)217 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
218 struct audioformat *fmt,
219 int source_id)
220 {
221 int err;
222 unsigned char data;
223 struct usb_device *dev = chip->dev;
224 u32 bmControls;
225
226 if (fmt->protocol == UAC_VERSION_3) {
227 struct uac3_clock_source_descriptor *cs_desc =
228 snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
229
230 if (!cs_desc)
231 return false;
232 bmControls = le32_to_cpu(cs_desc->bmControls);
233 } else { /* UAC_VERSION_1/2 */
234 struct uac_clock_source_descriptor *cs_desc =
235 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
236
237 if (!cs_desc)
238 return false;
239 bmControls = cs_desc->bmControls;
240 }
241
242 /* If a clock source can't tell us whether it's valid, we assume it is */
243 if (!uac_v2v3_control_is_readable(bmControls,
244 UAC2_CS_CONTROL_CLOCK_VALID))
245 return true;
246
247 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
248 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
249 UAC2_CS_CONTROL_CLOCK_VALID << 8,
250 snd_usb_ctrl_intf(chip) | (source_id << 8),
251 &data, sizeof(data));
252
253 if (err < 0) {
254 dev_warn(&dev->dev,
255 "%s(): cannot get clock validity for id %d\n",
256 __func__, source_id);
257 return false;
258 }
259
260 if (data)
261 return true;
262 else
263 return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
264 }
265
__uac_clock_find_source(struct snd_usb_audio * chip,struct audioformat * fmt,int entity_id,unsigned long * visited,bool validate)266 static int __uac_clock_find_source(struct snd_usb_audio *chip,
267 struct audioformat *fmt, int entity_id,
268 unsigned long *visited, bool validate)
269 {
270 struct uac_clock_source_descriptor *source;
271 struct uac_clock_selector_descriptor *selector;
272 struct uac_clock_multiplier_descriptor *multiplier;
273
274 entity_id &= 0xff;
275
276 if (test_and_set_bit(entity_id, visited)) {
277 usb_audio_warn(chip,
278 "%s(): recursive clock topology detected, id %d.\n",
279 __func__, entity_id);
280 return -EINVAL;
281 }
282
283 /* first, see if the ID we're looking for is a clock source already */
284 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
285 if (source) {
286 entity_id = source->bClockID;
287 if (validate && !uac_clock_source_is_valid(chip, fmt,
288 entity_id)) {
289 usb_audio_err(chip,
290 "clock source %d is not valid, cannot use\n",
291 entity_id);
292 return -ENXIO;
293 }
294 return entity_id;
295 }
296
297 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
298 if (selector) {
299 int ret, i, cur, err;
300
301 /* the entity ID we are looking for is a selector.
302 * find out what it currently selects */
303 ret = uac_clock_selector_get_val(chip, selector->bClockID);
304 if (ret < 0)
305 return ret;
306
307 /* Selector values are one-based */
308
309 if (ret > selector->bNrInPins || ret < 1) {
310 usb_audio_err(chip,
311 "%s(): selector reported illegal value, id %d, ret %d\n",
312 __func__, selector->bClockID, ret);
313
314 return -EINVAL;
315 }
316
317 cur = ret;
318 ret = __uac_clock_find_source(chip, fmt,
319 selector->baCSourceID[ret - 1],
320 visited, validate);
321 if (ret > 0) {
322 /*
323 * For Samsung USBC Headset (AKG), setting clock selector again
324 * will result in incorrect default clock setting problems
325 */
326 if (chip->usb_id == USB_ID(0x04e8, 0xa051))
327 return ret;
328 err = uac_clock_selector_set_val(chip, entity_id, cur);
329 if (err < 0)
330 return err;
331 }
332
333 if (!validate || ret > 0 || !chip->autoclock)
334 return ret;
335
336 /* The current clock source is invalid, try others. */
337 for (i = 1; i <= selector->bNrInPins; i++) {
338 if (i == cur)
339 continue;
340
341 ret = __uac_clock_find_source(chip, fmt,
342 selector->baCSourceID[i - 1],
343 visited, true);
344 if (ret < 0)
345 continue;
346
347 err = uac_clock_selector_set_val(chip, entity_id, i);
348 if (err < 0)
349 continue;
350
351 usb_audio_info(chip,
352 "found and selected valid clock source %d\n",
353 ret);
354 return ret;
355 }
356
357 return -ENXIO;
358 }
359
360 /* FIXME: multipliers only act as pass-thru element for now */
361 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
362 if (multiplier)
363 return __uac_clock_find_source(chip, fmt,
364 multiplier->bCSourceID,
365 visited, validate);
366
367 return -EINVAL;
368 }
369
__uac3_clock_find_source(struct snd_usb_audio * chip,struct audioformat * fmt,int entity_id,unsigned long * visited,bool validate)370 static int __uac3_clock_find_source(struct snd_usb_audio *chip,
371 struct audioformat *fmt, int entity_id,
372 unsigned long *visited, bool validate)
373 {
374 struct uac3_clock_source_descriptor *source;
375 struct uac3_clock_selector_descriptor *selector;
376 struct uac3_clock_multiplier_descriptor *multiplier;
377
378 entity_id &= 0xff;
379
380 if (test_and_set_bit(entity_id, visited)) {
381 usb_audio_warn(chip,
382 "%s(): recursive clock topology detected, id %d.\n",
383 __func__, entity_id);
384 return -EINVAL;
385 }
386
387 /* first, see if the ID we're looking for is a clock source already */
388 source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
389 if (source) {
390 entity_id = source->bClockID;
391 if (validate && !uac_clock_source_is_valid(chip, fmt,
392 entity_id)) {
393 usb_audio_err(chip,
394 "clock source %d is not valid, cannot use\n",
395 entity_id);
396 return -ENXIO;
397 }
398 return entity_id;
399 }
400
401 selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
402 if (selector) {
403 int ret, i, cur, err;
404
405 /* the entity ID we are looking for is a selector.
406 * find out what it currently selects */
407 ret = uac_clock_selector_get_val(chip, selector->bClockID);
408 if (ret < 0)
409 return ret;
410
411 /* Selector values are one-based */
412
413 if (ret > selector->bNrInPins || ret < 1) {
414 usb_audio_err(chip,
415 "%s(): selector reported illegal value, id %d, ret %d\n",
416 __func__, selector->bClockID, ret);
417
418 return -EINVAL;
419 }
420
421 cur = ret;
422 ret = __uac3_clock_find_source(chip, fmt,
423 selector->baCSourceID[ret - 1],
424 visited, validate);
425 if (ret > 0) {
426 err = uac_clock_selector_set_val(chip, entity_id, cur);
427 if (err < 0)
428 return err;
429 }
430
431 if (!validate || ret > 0 || !chip->autoclock)
432 return ret;
433
434 /* The current clock source is invalid, try others. */
435 for (i = 1; i <= selector->bNrInPins; i++) {
436 int err;
437
438 if (i == cur)
439 continue;
440
441 ret = __uac3_clock_find_source(chip, fmt,
442 selector->baCSourceID[i - 1],
443 visited, true);
444 if (ret < 0)
445 continue;
446
447 err = uac_clock_selector_set_val(chip, entity_id, i);
448 if (err < 0)
449 continue;
450
451 usb_audio_info(chip,
452 "found and selected valid clock source %d\n",
453 ret);
454 return ret;
455 }
456
457 return -ENXIO;
458 }
459
460 /* FIXME: multipliers only act as pass-thru element for now */
461 multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
462 entity_id);
463 if (multiplier)
464 return __uac3_clock_find_source(chip, fmt,
465 multiplier->bCSourceID,
466 visited, validate);
467
468 return -EINVAL;
469 }
470
471 /*
472 * For all kinds of sample rate settings and other device queries,
473 * the clock source (end-leaf) must be used. However, clock selectors,
474 * clock multipliers and sample rate converters may be specified as
475 * clock source input to terminal. This functions walks the clock path
476 * to its end and tries to find the source.
477 *
478 * The 'visited' bitfield is used internally to detect recursive loops.
479 *
480 * Returns the clock source UnitID (>=0) on success, or an error.
481 */
snd_usb_clock_find_source(struct snd_usb_audio * chip,struct audioformat * fmt,bool validate)482 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
483 struct audioformat *fmt, bool validate)
484 {
485 DECLARE_BITMAP(visited, 256);
486 memset(visited, 0, sizeof(visited));
487
488 switch (fmt->protocol) {
489 case UAC_VERSION_2:
490 return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
491 validate);
492 case UAC_VERSION_3:
493 return __uac3_clock_find_source(chip, fmt, fmt->clock, visited,
494 validate);
495 default:
496 return -EINVAL;
497 }
498 }
499
set_sample_rate_v1(struct snd_usb_audio * chip,int iface,struct usb_host_interface * alts,struct audioformat * fmt,int rate)500 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
501 struct usb_host_interface *alts,
502 struct audioformat *fmt, int rate)
503 {
504 struct usb_device *dev = chip->dev;
505 unsigned int ep;
506 unsigned char data[3];
507 int err, crate;
508
509 if (get_iface_desc(alts)->bNumEndpoints < 1)
510 return -EINVAL;
511 ep = get_endpoint(alts, 0)->bEndpointAddress;
512
513 /* if endpoint doesn't have sampling rate control, bail out */
514 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
515 return 0;
516
517 data[0] = rate;
518 data[1] = rate >> 8;
519 data[2] = rate >> 16;
520 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
521 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
522 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
523 data, sizeof(data));
524 if (err < 0) {
525 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
526 iface, fmt->altsetting, rate, ep);
527 return err;
528 }
529
530 /* Don't check the sample rate for devices which we know don't
531 * support reading */
532 if (snd_usb_get_sample_rate_quirk(chip))
533 return 0;
534 /* the firmware is likely buggy, don't repeat to fail too many times */
535 if (chip->sample_rate_read_error > 2)
536 return 0;
537
538 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
539 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
540 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
541 data, sizeof(data));
542 if (err < 0) {
543 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
544 iface, fmt->altsetting, ep);
545 chip->sample_rate_read_error++;
546 return 0; /* some devices don't support reading */
547 }
548
549 crate = data[0] | (data[1] << 8) | (data[2] << 16);
550 if (!crate) {
551 dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
552 chip->sample_rate_read_error = 3; /* three strikes, see above */
553 return 0;
554 }
555
556 if (crate != rate) {
557 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
558 // runtime->rate = crate;
559 }
560
561 return 0;
562 }
563
get_sample_rate_v2v3(struct snd_usb_audio * chip,int iface,int altsetting,int clock)564 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
565 int altsetting, int clock)
566 {
567 struct usb_device *dev = chip->dev;
568 __le32 data;
569 int err;
570
571 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
572 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
573 UAC2_CS_CONTROL_SAM_FREQ << 8,
574 snd_usb_ctrl_intf(chip) | (clock << 8),
575 &data, sizeof(data));
576 if (err < 0) {
577 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
578 iface, altsetting, err);
579 return 0;
580 }
581
582 return le32_to_cpu(data);
583 }
584
set_sample_rate_v2v3(struct snd_usb_audio * chip,int iface,struct usb_host_interface * alts,struct audioformat * fmt,int rate)585 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
586 struct usb_host_interface *alts,
587 struct audioformat *fmt, int rate)
588 {
589 struct usb_device *dev = chip->dev;
590 __le32 data;
591 int err, cur_rate, prev_rate;
592 int clock;
593 bool writeable;
594 u32 bmControls;
595
596 /* First, try to find a valid clock. This may trigger
597 * automatic clock selection if the current clock is not
598 * valid.
599 */
600 clock = snd_usb_clock_find_source(chip, fmt, true);
601 if (clock < 0) {
602 /* We did not find a valid clock, but that might be
603 * because the current sample rate does not match an
604 * external clock source. Try again without validation
605 * and we will do another validation after setting the
606 * rate.
607 */
608 clock = snd_usb_clock_find_source(chip, fmt, false);
609 if (clock < 0)
610 return clock;
611 }
612
613 prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
614 if (prev_rate == rate)
615 goto validation;
616
617 if (fmt->protocol == UAC_VERSION_3) {
618 struct uac3_clock_source_descriptor *cs_desc;
619
620 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
621 bmControls = le32_to_cpu(cs_desc->bmControls);
622 } else {
623 struct uac_clock_source_descriptor *cs_desc;
624
625 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
626 bmControls = cs_desc->bmControls;
627 }
628
629 writeable = uac_v2v3_control_is_writeable(bmControls,
630 UAC2_CS_CONTROL_SAM_FREQ);
631 if (writeable) {
632 data = cpu_to_le32(rate);
633 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
634 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
635 UAC2_CS_CONTROL_SAM_FREQ << 8,
636 snd_usb_ctrl_intf(chip) | (clock << 8),
637 &data, sizeof(data));
638 if (err < 0) {
639 usb_audio_err(chip,
640 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
641 iface, fmt->altsetting, rate, err);
642 return err;
643 }
644
645 cur_rate = get_sample_rate_v2v3(chip, iface,
646 fmt->altsetting, clock);
647 } else {
648 cur_rate = prev_rate;
649 }
650
651 if (cur_rate != rate) {
652 if (!writeable) {
653 usb_audio_warn(chip,
654 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
655 iface, fmt->altsetting, rate, cur_rate);
656 return -ENXIO;
657 }
658 usb_audio_dbg(chip,
659 "current rate %d is different from the runtime rate %d\n",
660 cur_rate, rate);
661 }
662
663 /* Some devices doesn't respond to sample rate changes while the
664 * interface is active. */
665 if (rate != prev_rate) {
666 usb_set_interface(dev, iface, 0);
667 snd_usb_set_interface_quirk(dev);
668 usb_set_interface(dev, iface, fmt->altsetting);
669 snd_usb_set_interface_quirk(dev);
670 }
671
672 validation:
673 /* validate clock after rate change */
674 if (!uac_clock_source_is_valid(chip, fmt, clock))
675 return -ENXIO;
676 return 0;
677 }
678
snd_usb_init_sample_rate(struct snd_usb_audio * chip,int iface,struct usb_host_interface * alts,struct audioformat * fmt,int rate)679 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
680 struct usb_host_interface *alts,
681 struct audioformat *fmt, int rate)
682 {
683 switch (fmt->protocol) {
684 case UAC_VERSION_1:
685 default:
686 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
687
688 case UAC_VERSION_3:
689 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
690 if (rate != UAC3_BADD_SAMPLING_RATE)
691 return -ENXIO;
692 else
693 return 0;
694 }
695 fallthrough;
696 case UAC_VERSION_2:
697 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);
698 }
699 }
700
701