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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
4  */
5 
6 #include <linux/usb.h>
7 #include <linux/gfp.h>
8 
9 #include "usb_stream.h"
10 
11 
12 /*                             setup                                  */
13 
usb_stream_next_packet_size(struct usb_stream_kernel * sk)14 static unsigned usb_stream_next_packet_size(struct usb_stream_kernel *sk)
15 {
16 	struct usb_stream *s = sk->s;
17 	sk->out_phase_peeked = (sk->out_phase & 0xffff) + sk->freqn;
18 	return (sk->out_phase_peeked >> 16) * s->cfg.frame_size;
19 }
20 
playback_prep_freqn(struct usb_stream_kernel * sk,struct urb * urb)21 static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb)
22 {
23 	struct usb_stream *s = sk->s;
24 	int pack, lb = 0;
25 
26 	for (pack = 0; pack < sk->n_o_ps; pack++) {
27 		int l = usb_stream_next_packet_size(sk);
28 		if (s->idle_outsize + lb + l > s->period_size)
29 			goto check;
30 
31 		sk->out_phase = sk->out_phase_peeked;
32 		urb->iso_frame_desc[pack].offset = lb;
33 		urb->iso_frame_desc[pack].length = l;
34 		lb += l;
35 	}
36 	snd_printdd(KERN_DEBUG "%i\n", lb);
37 
38 check:
39 	urb->number_of_packets = pack;
40 	urb->transfer_buffer_length = lb;
41 	s->idle_outsize += lb - s->period_size;
42 	snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
43 		    lb, s->period_size);
44 }
45 
init_pipe_urbs(struct usb_stream_kernel * sk,unsigned use_packsize,struct urb ** urbs,char * transfer,struct usb_device * dev,int pipe)46 static int init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
47 			   struct urb **urbs, char *transfer,
48 			   struct usb_device *dev, int pipe)
49 {
50 	int u, p;
51 	int maxpacket = use_packsize ?
52 		use_packsize : usb_maxpacket(dev, pipe, usb_pipeout(pipe));
53 	int transfer_length = maxpacket * sk->n_o_ps;
54 
55 	for (u = 0; u < USB_STREAM_NURBS;
56 	     ++u, transfer += transfer_length) {
57 		struct urb *urb = urbs[u];
58 		struct usb_iso_packet_descriptor *desc;
59 		urb->transfer_buffer = transfer;
60 		urb->dev = dev;
61 		urb->pipe = pipe;
62 		urb->number_of_packets = sk->n_o_ps;
63 		urb->context = sk;
64 		urb->interval = 1;
65 		if (usb_pipeout(pipe))
66 			continue;
67 		if (usb_urb_ep_type_check(urb))
68 			return -EINVAL;
69 
70 		urb->transfer_buffer_length = transfer_length;
71 		desc = urb->iso_frame_desc;
72 		desc->offset = 0;
73 		desc->length = maxpacket;
74 		for (p = 1; p < sk->n_o_ps; ++p) {
75 			desc[p].offset = desc[p - 1].offset + maxpacket;
76 			desc[p].length = maxpacket;
77 		}
78 	}
79 
80 	return 0;
81 }
82 
init_urbs(struct usb_stream_kernel * sk,unsigned use_packsize,struct usb_device * dev,int in_pipe,int out_pipe)83 static int init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
84 		      struct usb_device *dev, int in_pipe, int out_pipe)
85 {
86 	struct usb_stream	*s = sk->s;
87 	char			*indata = (char *)s + sizeof(*s) +
88 					sizeof(struct usb_stream_packet) *
89 					s->inpackets;
90 	int			u;
91 
92 	for (u = 0; u < USB_STREAM_NURBS; ++u) {
93 		sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
94 		if (!sk->inurb[u])
95 			return -ENOMEM;
96 
97 		sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
98 		if (!sk->outurb[u])
99 			return -ENOMEM;
100 	}
101 
102 	if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
103 	    init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
104 			   out_pipe))
105 		return -EINVAL;
106 
107 	return 0;
108 }
109 
110 
111 /*
112  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
113  * this will overflow at approx 524 kHz
114  */
get_usb_full_speed_rate(unsigned rate)115 static inline unsigned get_usb_full_speed_rate(unsigned rate)
116 {
117 	return ((rate << 13) + 62) / 125;
118 }
119 
120 /*
121  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
122  * this will overflow at approx 4 MHz
123  */
get_usb_high_speed_rate(unsigned rate)124 static inline unsigned get_usb_high_speed_rate(unsigned rate)
125 {
126 	return ((rate << 10) + 62) / 125;
127 }
128 
usb_stream_free(struct usb_stream_kernel * sk)129 void usb_stream_free(struct usb_stream_kernel *sk)
130 {
131 	struct usb_stream *s;
132 	unsigned u;
133 
134 	for (u = 0; u < USB_STREAM_NURBS; ++u) {
135 		usb_free_urb(sk->inurb[u]);
136 		sk->inurb[u] = NULL;
137 		usb_free_urb(sk->outurb[u]);
138 		sk->outurb[u] = NULL;
139 	}
140 
141 	s = sk->s;
142 	if (!s)
143 		return;
144 
145 	if (sk->write_page) {
146 		free_pages_exact(sk->write_page, s->write_size);
147 		sk->write_page = NULL;
148 	}
149 
150 	free_pages_exact(s, s->read_size);
151 	sk->s = NULL;
152 }
153 
usb_stream_new(struct usb_stream_kernel * sk,struct usb_device * dev,unsigned in_endpoint,unsigned out_endpoint,unsigned sample_rate,unsigned use_packsize,unsigned period_frames,unsigned frame_size)154 struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
155 				  struct usb_device *dev,
156 				  unsigned in_endpoint, unsigned out_endpoint,
157 				  unsigned sample_rate, unsigned use_packsize,
158 				  unsigned period_frames, unsigned frame_size)
159 {
160 	int packets, max_packsize;
161 	int in_pipe, out_pipe;
162 	int read_size = sizeof(struct usb_stream);
163 	int write_size;
164 	int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
165 
166 	in_pipe = usb_rcvisocpipe(dev, in_endpoint);
167 	out_pipe = usb_sndisocpipe(dev, out_endpoint);
168 
169 	max_packsize = use_packsize ?
170 		use_packsize : usb_maxpacket(dev, in_pipe, 0);
171 
172 	/*
173 		t_period = period_frames / sample_rate
174 		iso_packs = t_period / t_iso_frame
175 			= (period_frames / sample_rate) * (1 / t_iso_frame)
176 	*/
177 
178 	packets = period_frames * usb_frames / sample_rate + 1;
179 
180 	if (dev->speed == USB_SPEED_HIGH)
181 		packets = (packets + 7) & ~7;
182 
183 	read_size += packets * USB_STREAM_URBDEPTH *
184 		(max_packsize + sizeof(struct usb_stream_packet));
185 
186 	max_packsize = usb_maxpacket(dev, out_pipe, 1);
187 	write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
188 
189 	if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
190 		snd_printk(KERN_WARNING "a size exceeds 128*PAGE_SIZE\n");
191 		goto out;
192 	}
193 
194 	sk->s = alloc_pages_exact(read_size,
195 				  GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
196 	if (!sk->s) {
197 		pr_warn("us122l: couldn't allocate read buffer\n");
198 		goto out;
199 	}
200 	sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
201 
202 	sk->s->read_size = read_size;
203 
204 	sk->s->cfg.sample_rate = sample_rate;
205 	sk->s->cfg.frame_size = frame_size;
206 	sk->n_o_ps = packets;
207 	sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
208 	sk->s->cfg.period_frames = period_frames;
209 	sk->s->period_size = frame_size * period_frames;
210 
211 	sk->s->write_size = write_size;
212 
213 	sk->write_page = alloc_pages_exact(write_size,
214 					   GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
215 	if (!sk->write_page) {
216 		pr_warn("us122l: couldn't allocate write buffer\n");
217 		usb_stream_free(sk);
218 		return NULL;
219 	}
220 
221 	/* calculate the frequency in 16.16 format */
222 	if (dev->speed == USB_SPEED_FULL)
223 		sk->freqn = get_usb_full_speed_rate(sample_rate);
224 	else
225 		sk->freqn = get_usb_high_speed_rate(sample_rate);
226 
227 	if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
228 		usb_stream_free(sk);
229 		return NULL;
230 	}
231 
232 	sk->s->state = usb_stream_stopped;
233 out:
234 	return sk->s;
235 }
236 
237 
238 /*                             start                                  */
239 
balance_check(struct usb_stream_kernel * sk,struct urb * urb)240 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
241 {
242 	bool r;
243 	if (unlikely(urb->status)) {
244 		if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
245 			snd_printk(KERN_WARNING "status=%i\n", urb->status);
246 		sk->iso_frame_balance = 0x7FFFFFFF;
247 		return false;
248 	}
249 	r = sk->iso_frame_balance == 0;
250 	if (!r)
251 		sk->i_urb = urb;
252 	return r;
253 }
254 
balance_playback(struct usb_stream_kernel * sk,struct urb * urb)255 static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
256 {
257 	sk->iso_frame_balance += urb->number_of_packets;
258 	return balance_check(sk, urb);
259 }
260 
balance_capture(struct usb_stream_kernel * sk,struct urb * urb)261 static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
262 {
263 	sk->iso_frame_balance -= urb->number_of_packets;
264 	return balance_check(sk, urb);
265 }
266 
subs_set_complete(struct urb ** urbs,void (* complete)(struct urb *))267 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
268 {
269 	int u;
270 
271 	for (u = 0; u < USB_STREAM_NURBS; u++) {
272 		struct urb *urb = urbs[u];
273 		urb->complete = complete;
274 	}
275 }
276 
usb_stream_prepare_playback(struct usb_stream_kernel * sk,struct urb * inurb)277 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
278 		struct urb *inurb)
279 {
280 	struct usb_stream *s = sk->s;
281 	struct urb *io;
282 	struct usb_iso_packet_descriptor *id, *od;
283 	int p = 0, lb = 0, l = 0;
284 
285 	io = sk->idle_outurb;
286 	od = io->iso_frame_desc;
287 
288 	for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
289 		struct urb *ii = sk->completed_inurb;
290 		id = ii->iso_frame_desc +
291 			ii->number_of_packets + s->sync_packet;
292 		l = id->actual_length;
293 
294 		od[p].length = l;
295 		od[p].offset = lb;
296 		lb += l;
297 	}
298 
299 	for (;
300 	     s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
301 	     ++p, ++s->sync_packet) {
302 		l = inurb->iso_frame_desc[s->sync_packet].actual_length;
303 
304 		if (s->idle_outsize + lb + l > s->period_size)
305 			goto check_ok;
306 
307 		od[p].length = l;
308 		od[p].offset = lb;
309 		lb += l;
310 	}
311 
312 check_ok:
313 	s->sync_packet -= inurb->number_of_packets;
314 	if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
315 		snd_printk(KERN_WARNING "invalid sync_packet = %i;"
316 			   " p=%i nop=%i %i %x %x %x > %x\n",
317 			   s->sync_packet, p, inurb->number_of_packets,
318 			   s->idle_outsize + lb + l,
319 			   s->idle_outsize, lb,  l,
320 			   s->period_size);
321 		return -1;
322 	}
323 	if (unlikely(lb % s->cfg.frame_size)) {
324 		snd_printk(KERN_WARNING"invalid outsize = %i\n",
325 			   lb);
326 		return -1;
327 	}
328 	s->idle_outsize += lb - s->period_size;
329 	io->number_of_packets = p;
330 	io->transfer_buffer_length = lb;
331 	if (s->idle_outsize <= 0)
332 		return 0;
333 
334 	snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
335 	return -1;
336 }
337 
prepare_inurb(int number_of_packets,struct urb * iu)338 static void prepare_inurb(int number_of_packets, struct urb *iu)
339 {
340 	struct usb_iso_packet_descriptor *id;
341 	int p;
342 
343 	iu->number_of_packets = number_of_packets;
344 	id = iu->iso_frame_desc;
345 	id->offset = 0;
346 	for (p = 0; p < iu->number_of_packets - 1; ++p)
347 		id[p + 1].offset = id[p].offset + id[p].length;
348 
349 	iu->transfer_buffer_length =
350 		id[0].length * iu->number_of_packets;
351 }
352 
submit_urbs(struct usb_stream_kernel * sk,struct urb * inurb,struct urb * outurb)353 static int submit_urbs(struct usb_stream_kernel *sk,
354 		       struct urb *inurb, struct urb *outurb)
355 {
356 	int err;
357 	prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
358 	err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
359 	if (err < 0)
360 		goto report_failure;
361 
362 	sk->idle_inurb = sk->completed_inurb;
363 	sk->completed_inurb = inurb;
364 	err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
365 	if (err < 0)
366 		goto report_failure;
367 
368 	sk->idle_outurb = sk->completed_outurb;
369 	sk->completed_outurb = outurb;
370 	return 0;
371 
372 report_failure:
373 	snd_printk(KERN_ERR "%i\n", err);
374 	return err;
375 }
376 
377 #ifdef DEBUG_LOOP_BACK
378 /*
379   This loop_back() shows how to read/write the period data.
380  */
loop_back(struct usb_stream * s)381 static void loop_back(struct usb_stream *s)
382 {
383 	char *i, *o;
384 	int il, ol, l, p;
385 	struct urb *iu;
386 	struct usb_iso_packet_descriptor *id;
387 
388 	o = s->playback1st_to;
389 	ol = s->playback1st_size;
390 	l = 0;
391 
392 	if (s->insplit_pack >= 0) {
393 		iu = sk->idle_inurb;
394 		id = iu->iso_frame_desc;
395 		p = s->insplit_pack;
396 	} else
397 		goto second;
398 loop:
399 	for (; p < iu->number_of_packets && l < s->period_size; ++p) {
400 		i = iu->transfer_buffer + id[p].offset;
401 		il = id[p].actual_length;
402 		if (l + il > s->period_size)
403 			il = s->period_size - l;
404 		if (il <= ol) {
405 			memcpy(o, i, il);
406 			o += il;
407 			ol -= il;
408 		} else {
409 			memcpy(o, i, ol);
410 			singen_6pack(o, ol);
411 			o = s->playback_to;
412 			memcpy(o, i + ol, il - ol);
413 			o += il - ol;
414 			ol = s->period_size - s->playback1st_size;
415 		}
416 		l += il;
417 	}
418 	if (iu == sk->completed_inurb) {
419 		if (l != s->period_size)
420 			printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
421 			       l/(int)s->cfg.frame_size);
422 
423 		return;
424 	}
425 second:
426 	iu = sk->completed_inurb;
427 	id = iu->iso_frame_desc;
428 	p = 0;
429 	goto loop;
430 
431 }
432 #else
loop_back(struct usb_stream * s)433 static void loop_back(struct usb_stream *s)
434 {
435 }
436 #endif
437 
stream_idle(struct usb_stream_kernel * sk,struct urb * inurb,struct urb * outurb)438 static void stream_idle(struct usb_stream_kernel *sk,
439 			struct urb *inurb, struct urb *outurb)
440 {
441 	struct usb_stream *s = sk->s;
442 	int l, p;
443 	int insize = s->idle_insize;
444 	int urb_size = 0;
445 
446 	s->inpacket_split = s->next_inpacket_split;
447 	s->inpacket_split_at = s->next_inpacket_split_at;
448 	s->next_inpacket_split = -1;
449 	s->next_inpacket_split_at = 0;
450 
451 	for (p = 0; p < inurb->number_of_packets; ++p) {
452 		struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
453 		l = id[p].actual_length;
454 		if (unlikely(l == 0 || id[p].status)) {
455 			snd_printk(KERN_WARNING "underrun, status=%u\n",
456 				   id[p].status);
457 			goto err_out;
458 		}
459 		s->inpacket_head++;
460 		s->inpacket_head %= s->inpackets;
461 		if (s->inpacket_split == -1)
462 			s->inpacket_split = s->inpacket_head;
463 
464 		s->inpacket[s->inpacket_head].offset =
465 			id[p].offset + (inurb->transfer_buffer - (void *)s);
466 		s->inpacket[s->inpacket_head].length = l;
467 		if (insize + l > s->period_size &&
468 		    s->next_inpacket_split == -1) {
469 			s->next_inpacket_split = s->inpacket_head;
470 			s->next_inpacket_split_at = s->period_size - insize;
471 		}
472 		insize += l;
473 		urb_size += l;
474 	}
475 	s->idle_insize += urb_size - s->period_size;
476 	if (s->idle_insize < 0) {
477 		snd_printk(KERN_WARNING "%i\n",
478 			   (s->idle_insize)/(int)s->cfg.frame_size);
479 		goto err_out;
480 	}
481 	s->insize_done += urb_size;
482 
483 	l = s->idle_outsize;
484 	s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
485 				  sk->write_page) - l;
486 
487 	if (usb_stream_prepare_playback(sk, inurb) < 0)
488 		goto err_out;
489 
490 	s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
491 	s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
492 		sk->write_page;
493 
494 	if (submit_urbs(sk, inurb, outurb) < 0)
495 		goto err_out;
496 
497 	loop_back(s);
498 	s->periods_done++;
499 	wake_up_all(&sk->sleep);
500 	return;
501 err_out:
502 	s->state = usb_stream_xrun;
503 	wake_up_all(&sk->sleep);
504 }
505 
i_capture_idle(struct urb * urb)506 static void i_capture_idle(struct urb *urb)
507 {
508 	struct usb_stream_kernel *sk = urb->context;
509 	if (balance_capture(sk, urb))
510 		stream_idle(sk, urb, sk->i_urb);
511 }
512 
i_playback_idle(struct urb * urb)513 static void i_playback_idle(struct urb *urb)
514 {
515 	struct usb_stream_kernel *sk = urb->context;
516 	if (balance_playback(sk, urb))
517 		stream_idle(sk, sk->i_urb, urb);
518 }
519 
stream_start(struct usb_stream_kernel * sk,struct urb * inurb,struct urb * outurb)520 static void stream_start(struct usb_stream_kernel *sk,
521 			 struct urb *inurb, struct urb *outurb)
522 {
523 	struct usb_stream *s = sk->s;
524 	if (s->state >= usb_stream_sync1) {
525 		int l, p, max_diff, max_diff_0;
526 		int urb_size = 0;
527 		unsigned frames_per_packet, min_frames = 0;
528 		frames_per_packet = (s->period_size - s->idle_insize);
529 		frames_per_packet <<= 8;
530 		frames_per_packet /=
531 			s->cfg.frame_size * inurb->number_of_packets;
532 		frames_per_packet++;
533 
534 		max_diff_0 = s->cfg.frame_size;
535 		if (s->cfg.period_frames >= 256)
536 			max_diff_0 <<= 1;
537 		if (s->cfg.period_frames >= 1024)
538 			max_diff_0 <<= 1;
539 		max_diff = max_diff_0;
540 		for (p = 0; p < inurb->number_of_packets; ++p) {
541 			int diff;
542 			l = inurb->iso_frame_desc[p].actual_length;
543 			urb_size += l;
544 
545 			min_frames += frames_per_packet;
546 			diff = urb_size -
547 				(min_frames >> 8) * s->cfg.frame_size;
548 			if (diff < max_diff) {
549 				snd_printdd(KERN_DEBUG "%i %i %i %i\n",
550 					    s->insize_done,
551 					    urb_size / (int)s->cfg.frame_size,
552 					    inurb->number_of_packets, diff);
553 				max_diff = diff;
554 			}
555 		}
556 		s->idle_insize -= max_diff - max_diff_0;
557 		s->idle_insize += urb_size - s->period_size;
558 		if (s->idle_insize < 0) {
559 			snd_printk(KERN_WARNING "%i %i %i\n",
560 				   s->idle_insize, urb_size, s->period_size);
561 			return;
562 		} else if (s->idle_insize == 0) {
563 			s->next_inpacket_split =
564 				(s->inpacket_head + 1) % s->inpackets;
565 			s->next_inpacket_split_at = 0;
566 		} else {
567 			unsigned split = s->inpacket_head;
568 			l = s->idle_insize;
569 			while (l > s->inpacket[split].length) {
570 				l -= s->inpacket[split].length;
571 				if (split == 0)
572 					split = s->inpackets - 1;
573 				else
574 					split--;
575 			}
576 			s->next_inpacket_split = split;
577 			s->next_inpacket_split_at =
578 				s->inpacket[split].length - l;
579 		}
580 
581 		s->insize_done += urb_size;
582 
583 		if (usb_stream_prepare_playback(sk, inurb) < 0)
584 			return;
585 
586 	} else
587 		playback_prep_freqn(sk, sk->idle_outurb);
588 
589 	if (submit_urbs(sk, inurb, outurb) < 0)
590 		return;
591 
592 	if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
593 		/* just guesswork                            ^^^^^^ */
594 		s->state = usb_stream_ready;
595 		subs_set_complete(sk->inurb, i_capture_idle);
596 		subs_set_complete(sk->outurb, i_playback_idle);
597 	}
598 }
599 
i_capture_start(struct urb * urb)600 static void i_capture_start(struct urb *urb)
601 {
602 	struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
603 	struct usb_stream_kernel *sk = urb->context;
604 	struct usb_stream *s = sk->s;
605 	int p;
606 	int empty = 0;
607 
608 	if (urb->status) {
609 		snd_printk(KERN_WARNING "status=%i\n", urb->status);
610 		return;
611 	}
612 
613 	for (p = 0; p < urb->number_of_packets; ++p) {
614 		int l = id[p].actual_length;
615 		if (l < s->cfg.frame_size) {
616 			++empty;
617 			if (s->state >= usb_stream_sync0) {
618 				snd_printk(KERN_WARNING "%i\n", l);
619 				return;
620 			}
621 		}
622 		s->inpacket_head++;
623 		s->inpacket_head %= s->inpackets;
624 		s->inpacket[s->inpacket_head].offset =
625 			id[p].offset + (urb->transfer_buffer - (void *)s);
626 		s->inpacket[s->inpacket_head].length = l;
627 	}
628 #ifdef SHOW_EMPTY
629 	if (empty) {
630 		printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
631 		       urb->iso_frame_desc[0].actual_length);
632 		for (pack = 1; pack < urb->number_of_packets; ++pack) {
633 			int l = urb->iso_frame_desc[pack].actual_length;
634 			printk(KERN_CONT " %i", l);
635 		}
636 		printk(KERN_CONT "\n");
637 	}
638 #endif
639 	if (!empty && s->state < usb_stream_sync1)
640 		++s->state;
641 
642 	if (balance_capture(sk, urb))
643 		stream_start(sk, urb, sk->i_urb);
644 }
645 
i_playback_start(struct urb * urb)646 static void i_playback_start(struct urb *urb)
647 {
648 	struct usb_stream_kernel *sk = urb->context;
649 	if (balance_playback(sk, urb))
650 		stream_start(sk, sk->i_urb, urb);
651 }
652 
usb_stream_start(struct usb_stream_kernel * sk)653 int usb_stream_start(struct usb_stream_kernel *sk)
654 {
655 	struct usb_stream *s = sk->s;
656 	int frame = 0, iters = 0;
657 	int u, err;
658 	int try = 0;
659 
660 	if (s->state != usb_stream_stopped)
661 		return -EAGAIN;
662 
663 	subs_set_complete(sk->inurb, i_capture_start);
664 	subs_set_complete(sk->outurb, i_playback_start);
665 	memset(sk->write_page, 0, s->write_size);
666 dotry:
667 	s->insize_done = 0;
668 	s->idle_insize = 0;
669 	s->idle_outsize = 0;
670 	s->sync_packet = -1;
671 	s->inpacket_head = -1;
672 	sk->iso_frame_balance = 0;
673 	++try;
674 	for (u = 0; u < 2; u++) {
675 		struct urb *inurb = sk->inurb[u];
676 		struct urb *outurb = sk->outurb[u];
677 		playback_prep_freqn(sk, outurb);
678 		inurb->number_of_packets = outurb->number_of_packets;
679 		inurb->transfer_buffer_length =
680 			inurb->number_of_packets *
681 			inurb->iso_frame_desc[0].length;
682 
683 		if (u == 0) {
684 			int now;
685 			struct usb_device *dev = inurb->dev;
686 			frame = usb_get_current_frame_number(dev);
687 			do {
688 				now = usb_get_current_frame_number(dev);
689 				++iters;
690 			} while (now > -1 && now == frame);
691 		}
692 		err = usb_submit_urb(inurb, GFP_ATOMIC);
693 		if (err < 0) {
694 			snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
695 				   " returned %i\n", u, err);
696 			return err;
697 		}
698 		err = usb_submit_urb(outurb, GFP_ATOMIC);
699 		if (err < 0) {
700 			snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
701 				   " returned %i\n", u, err);
702 			return err;
703 		}
704 
705 		if (inurb->start_frame != outurb->start_frame) {
706 			snd_printd(KERN_DEBUG
707 				   "u[%i] start_frames differ in:%u out:%u\n",
708 				   u, inurb->start_frame, outurb->start_frame);
709 			goto check_retry;
710 		}
711 	}
712 	snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
713 	try = 0;
714 check_retry:
715 	if (try) {
716 		usb_stream_stop(sk);
717 		if (try < 5) {
718 			msleep(1500);
719 			snd_printd(KERN_DEBUG "goto dotry;\n");
720 			goto dotry;
721 		}
722 		snd_printk(KERN_WARNING"couldn't start"
723 			   " all urbs on the same start_frame.\n");
724 		return -EFAULT;
725 	}
726 
727 	sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
728 	sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
729 	sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
730 	sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
731 
732 /* wait, check */
733 	{
734 		int wait_ms = 3000;
735 		while (s->state != usb_stream_ready && wait_ms > 0) {
736 			snd_printdd(KERN_DEBUG "%i\n", s->state);
737 			msleep(200);
738 			wait_ms -= 200;
739 		}
740 	}
741 
742 	return s->state == usb_stream_ready ? 0 : -EFAULT;
743 }
744 
745 
746 /*                             stop                                   */
747 
usb_stream_stop(struct usb_stream_kernel * sk)748 void usb_stream_stop(struct usb_stream_kernel *sk)
749 {
750 	int u;
751 	if (!sk->s)
752 		return;
753 	for (u = 0; u < USB_STREAM_NURBS; ++u) {
754 		usb_kill_urb(sk->inurb[u]);
755 		usb_kill_urb(sk->outurb[u]);
756 	}
757 	sk->s->state = usb_stream_stopped;
758 	msleep(400);
759 }
760