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usb_stream.c

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linux-6.19.14/sound/usb/usx2y/usb_stream.c C
  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/*                             setup                                  */
 12
 13static unsigned int usb_stream_next_packet_size(struct usb_stream_kernel *sk)
 14{
 15	struct usb_stream *s = sk->s;
 16
 17	sk->out_phase_peeked = (sk->out_phase & 0xffff) + sk->freqn;
 18	return (sk->out_phase_peeked >> 16) * s->cfg.frame_size;
 19}
 20
 21static 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
 29		if (s->idle_outsize + lb + l > s->period_size)
 30			goto check;
 31
 32		sk->out_phase = sk->out_phase_peeked;
 33		urb->iso_frame_desc[pack].offset = lb;
 34		urb->iso_frame_desc[pack].length = l;
 35		lb += l;
 36	}
 37
 38check:
 39	urb->number_of_packets = pack;
 40	urb->transfer_buffer_length = lb;
 41	s->idle_outsize += lb - s->period_size;
 42}
 43
 44static int init_pipe_urbs(struct usb_stream_kernel *sk,
 45			  unsigned int use_packsize,
 46			  struct urb **urbs, char *transfer,
 47			  struct usb_device *dev, int pipe)
 48{
 49	int u, p;
 50	int maxpacket = use_packsize ?
 51		use_packsize : usb_maxpacket(dev, pipe);
 52	int transfer_length = maxpacket * sk->n_o_ps;
 53
 54	for (u = 0; u < USB_STREAM_NURBS;
 55	     ++u, transfer += transfer_length) {
 56		struct urb *urb = urbs[u];
 57		struct usb_iso_packet_descriptor *desc;
 58
 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
 83static int init_urbs(struct usb_stream_kernel *sk, unsigned int use_packsize,
 84		     struct usb_device *dev, int in_pipe, int out_pipe)
 85{
 86	struct usb_stream	*s = sk->s;
 87	char			*indata =
 88		(char *)s + sizeof(*s) + sizeof(struct usb_stream_packet) * s->inpackets;
 89	int			u;
 90
 91	for (u = 0; u < USB_STREAM_NURBS; ++u) {
 92		sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
 93		if (!sk->inurb[u])
 94			return -ENOMEM;
 95
 96		sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
 97		if (!sk->outurb[u])
 98			return -ENOMEM;
 99	}
100
101	if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
102	    init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
103			   out_pipe))
104		return -EINVAL;
105
106	return 0;
107}
108
109/*
110 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
111 * this will overflow at approx 524 kHz
112 */
113static inline unsigned int get_usb_full_speed_rate(unsigned int rate)
114{
115	return ((rate << 13) + 62) / 125;
116}
117
118/*
119 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
120 * this will overflow at approx 4 MHz
121 */
122static inline unsigned int get_usb_high_speed_rate(unsigned int rate)
123{
124	return ((rate << 10) + 62) / 125;
125}
126
127void usb_stream_free(struct usb_stream_kernel *sk)
128{
129	struct usb_stream *s;
130	unsigned int u;
131
132	for (u = 0; u < USB_STREAM_NURBS; ++u) {
133		usb_free_urb(sk->inurb[u]);
134		sk->inurb[u] = NULL;
135		usb_free_urb(sk->outurb[u]);
136		sk->outurb[u] = NULL;
137	}
138
139	s = sk->s;
140	if (!s)
141		return;
142
143	if (sk->write_page) {
144		free_pages_exact(sk->write_page, s->write_size);
145		sk->write_page = NULL;
146	}
147
148	free_pages_exact(s, s->read_size);
149	sk->s = NULL;
150}
151
152struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
153				  struct usb_device *dev,
154				  unsigned int in_endpoint,
155				  unsigned int out_endpoint,
156				  unsigned int sample_rate,
157				  unsigned int use_packsize,
158				  unsigned int period_frames,
159				  unsigned int frame_size)
160{
161	int packets, max_packsize;
162	int in_pipe, out_pipe;
163	int read_size = sizeof(struct usb_stream);
164	int write_size;
165	int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
166
167	in_pipe = usb_rcvisocpipe(dev, in_endpoint);
168	out_pipe = usb_sndisocpipe(dev, out_endpoint);
169
170	max_packsize = use_packsize ?
171		use_packsize : usb_maxpacket(dev, in_pipe);
172
173	/*
174		t_period = period_frames / sample_rate
175		iso_packs = t_period / t_iso_frame
176			= (period_frames / sample_rate) * (1 / t_iso_frame)
177	*/
178
179	packets = period_frames * usb_frames / sample_rate + 1;
180
181	if (dev->speed == USB_SPEED_HIGH)
182		packets = (packets + 7) & ~7;
183
184	read_size += packets * USB_STREAM_URBDEPTH *
185		(max_packsize + sizeof(struct usb_stream_packet));
186
187	max_packsize = usb_maxpacket(dev, out_pipe);
188	write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
189
190	if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
191		dev_warn(&dev->dev, "%s: a size exceeds 128*PAGE_SIZE\n", __func__);
192		goto out;
193	}
194
195	sk->s = alloc_pages_exact(read_size,
196				  GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
197	if (!sk->s) {
198		dev_warn(&dev->dev, "us122l: couldn't allocate read buffer\n");
199		goto out;
200	}
201	sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
202
203	sk->s->read_size = read_size;
204
205	sk->s->cfg.sample_rate = sample_rate;
206	sk->s->cfg.frame_size = frame_size;
207	sk->n_o_ps = packets;
208	sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
209	sk->s->cfg.period_frames = period_frames;
210	sk->s->period_size = frame_size * period_frames;
211
212	sk->s->write_size = write_size;
213
214	sk->write_page = alloc_pages_exact(write_size,
215					   GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
216	if (!sk->write_page) {
217		dev_warn(&dev->dev, "us122l: couldn't allocate write buffer\n");
218		usb_stream_free(sk);
219		return NULL;
220	}
221
222	/* calculate the frequency in 16.16 format */
223	if (dev->speed == USB_SPEED_FULL)
224		sk->freqn = get_usb_full_speed_rate(sample_rate);
225	else
226		sk->freqn = get_usb_high_speed_rate(sample_rate);
227
228	if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
229		usb_stream_free(sk);
230		return NULL;
231	}
232
233	sk->s->state = usb_stream_stopped;
234out:
235	return sk->s;
236}
237
238/*                             start                                  */
239
240static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
241{
242	bool r;
243
244	if (unlikely(urb->status)) {
245		if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
246			dev_warn(&sk->dev->dev, "%s: status=%i\n", __func__,
247				 urb->status);
248		sk->iso_frame_balance = 0x7FFFFFFF;
249		return false;
250	}
251	r = sk->iso_frame_balance == 0;
252	if (!r)
253		sk->i_urb = urb;
254	return r;
255}
256
257static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
258{
259	sk->iso_frame_balance += urb->number_of_packets;
260	return balance_check(sk, urb);
261}
262
263static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
264{
265	sk->iso_frame_balance -= urb->number_of_packets;
266	return balance_check(sk, urb);
267}
268
269static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
270{
271	int u;
272
273	for (u = 0; u < USB_STREAM_NURBS; u++) {
274		struct urb *urb = urbs[u];
275
276		urb->complete = complete;
277	}
278}
279
280static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
281		struct urb *inurb)
282{
283	struct usb_stream *s = sk->s;
284	struct urb *io;
285	struct usb_iso_packet_descriptor *id, *od;
286	int p = 0, lb = 0, l = 0;
287
288	io = sk->idle_outurb;
289	od = io->iso_frame_desc;
290
291	for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
292		struct urb *ii = sk->completed_inurb;
293
294		id = ii->iso_frame_desc +
295			ii->number_of_packets + s->sync_packet;
296		l = id->actual_length;
297
298		od[p].length = l;
299		od[p].offset = lb;
300		lb += l;
301	}
302
303	for (;
304	     s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
305	     ++p, ++s->sync_packet) {
306		l = inurb->iso_frame_desc[s->sync_packet].actual_length;
307
308		if (s->idle_outsize + lb + l > s->period_size)
309			goto check_ok;
310
311		od[p].length = l;
312		od[p].offset = lb;
313		lb += l;
314	}
315
316check_ok:
317	s->sync_packet -= inurb->number_of_packets;
318	if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
319		dev_warn(&sk->dev->dev,
320			 "%s: invalid sync_packet = %i; p=%i nop=%i %i %x %x %x > %x\n",
321			 __func__,
322			 s->sync_packet, p, inurb->number_of_packets,
323			 s->idle_outsize + lb + l,
324			 s->idle_outsize, lb,  l,
325			 s->period_size);
326		return -1;
327	}
328	if (unlikely(lb % s->cfg.frame_size)) {
329		dev_warn(&sk->dev->dev, "%s: invalid outsize = %i\n",
330			 __func__, lb);
331		return -1;
332	}
333	s->idle_outsize += lb - s->period_size;
334	io->number_of_packets = p;
335	io->transfer_buffer_length = lb;
336	if (s->idle_outsize <= 0)
337		return 0;
338
339	dev_warn(&sk->dev->dev, "%s: idle=%i\n", __func__, s->idle_outsize);
340	return -1;
341}
342
343static void prepare_inurb(int number_of_packets, struct urb *iu)
344{
345	struct usb_iso_packet_descriptor *id;
346	int p;
347
348	iu->number_of_packets = number_of_packets;
349	id = iu->iso_frame_desc;
350	id->offset = 0;
351	for (p = 0; p < iu->number_of_packets - 1; ++p)
352		id[p + 1].offset = id[p].offset + id[p].length;
353
354	iu->transfer_buffer_length =
355		id[0].length * iu->number_of_packets;
356}
357
358static int submit_urbs(struct usb_stream_kernel *sk,
359		       struct urb *inurb, struct urb *outurb)
360{
361	int err;
362
363	prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
364	err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
365	if (err < 0)
366		goto report_failure;
367
368	sk->idle_inurb = sk->completed_inurb;
369	sk->completed_inurb = inurb;
370	err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
371	if (err < 0)
372		goto report_failure;
373
374	sk->idle_outurb = sk->completed_outurb;
375	sk->completed_outurb = outurb;
376	return 0;
377
378report_failure:
379	dev_err(&sk->dev->dev, "%s error: %i\n", __func__, err);
380	return err;
381}
382
383#ifdef DEBUG_LOOP_BACK
384/*
385  This loop_back() shows how to read/write the period data.
386 */
387static void loop_back(struct usb_stream *s)
388{
389	char *i, *o;
390	int il, ol, l, p;
391	struct urb *iu;
392	struct usb_iso_packet_descriptor *id;
393
394	o = s->playback1st_to;
395	ol = s->playback1st_size;
396	l = 0;
397
398	if (s->insplit_pack >= 0) {
399		iu = sk->idle_inurb;
400		id = iu->iso_frame_desc;
401		p = s->insplit_pack;
402	} else
403		goto second;
404loop:
405	for (; p < iu->number_of_packets && l < s->period_size; ++p) {
406		i = iu->transfer_buffer + id[p].offset;
407		il = id[p].actual_length;
408		if (l + il > s->period_size)
409			il = s->period_size - l;
410		if (il <= ol) {
411			memcpy(o, i, il);
412			o += il;
413			ol -= il;
414		} else {
415			memcpy(o, i, ol);
416			singen_6pack(o, ol);
417			o = s->playback_to;
418			memcpy(o, i + ol, il - ol);
419			o += il - ol;
420			ol = s->period_size - s->playback1st_size;
421		}
422		l += il;
423	}
424	if (iu == sk->completed_inurb) {
425		if (l != s->period_size)
426			dev_dbg(&sk->dev->dev, "%s:%i %i\n", __func__, __LINE__,
427				l/(int)s->cfg.frame_size);
428
429		return;
430	}
431second:
432	iu = sk->completed_inurb;
433	id = iu->iso_frame_desc;
434	p = 0;
435	goto loop;
436
437}
438#else
439static void loop_back(struct usb_stream *s)
440{
441}
442#endif
443
444static void stream_idle(struct usb_stream_kernel *sk,
445			struct urb *inurb, struct urb *outurb)
446{
447	struct usb_stream *s = sk->s;
448	int l, p;
449	int insize = s->idle_insize;
450	int urb_size = 0;
451
452	s->inpacket_split = s->next_inpacket_split;
453	s->inpacket_split_at = s->next_inpacket_split_at;
454	s->next_inpacket_split = -1;
455	s->next_inpacket_split_at = 0;
456
457	for (p = 0; p < inurb->number_of_packets; ++p) {
458		struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
459
460		l = id[p].actual_length;
461		if (unlikely(l == 0 || id[p].status)) {
462			dev_warn(&sk->dev->dev, "%s: underrun, status=%u\n",
463				 __func__, id[p].status);
464			goto err_out;
465		}
466		s->inpacket_head++;
467		s->inpacket_head %= s->inpackets;
468		if (s->inpacket_split == -1)
469			s->inpacket_split = s->inpacket_head;
470
471		s->inpacket[s->inpacket_head].offset =
472			id[p].offset + (inurb->transfer_buffer - (void *)s);
473		s->inpacket[s->inpacket_head].length = l;
474		if (insize + l > s->period_size &&
475		    s->next_inpacket_split == -1) {
476			s->next_inpacket_split = s->inpacket_head;
477			s->next_inpacket_split_at = s->period_size - insize;
478		}
479		insize += l;
480		urb_size += l;
481	}
482	s->idle_insize += urb_size - s->period_size;
483	if (s->idle_insize < 0) {
484		dev_warn(&sk->dev->dev, "%s error: %i\n", __func__,
485			 (s->idle_insize)/(int)s->cfg.frame_size);
486		goto err_out;
487	}
488	s->insize_done += urb_size;
489
490	l = s->idle_outsize;
491	s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
492				  sk->write_page) - l;
493
494	if (usb_stream_prepare_playback(sk, inurb) < 0)
495		goto err_out;
496
497	s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
498	s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
499		sk->write_page;
500
501	if (submit_urbs(sk, inurb, outurb) < 0)
502		goto err_out;
503
504	loop_back(s);
505	s->periods_done++;
506	wake_up_all(&sk->sleep);
507	return;
508err_out:
509	s->state = usb_stream_xrun;
510	wake_up_all(&sk->sleep);
511}
512
513static void i_capture_idle(struct urb *urb)
514{
515	struct usb_stream_kernel *sk = urb->context;
516
517	if (balance_capture(sk, urb))
518		stream_idle(sk, urb, sk->i_urb);
519}
520
521static void i_playback_idle(struct urb *urb)
522{
523	struct usb_stream_kernel *sk = urb->context;
524
525	if (balance_playback(sk, urb))
526		stream_idle(sk, sk->i_urb, urb);
527}
528
529static void stream_start(struct usb_stream_kernel *sk,
530			 struct urb *inurb, struct urb *outurb)
531{
532	struct usb_stream *s = sk->s;
533
534	if (s->state >= usb_stream_sync1) {
535		int l, p, max_diff, max_diff_0;
536		int urb_size = 0;
537		unsigned int frames_per_packet, min_frames = 0;
538
539		frames_per_packet = (s->period_size - s->idle_insize);
540		frames_per_packet <<= 8;
541		frames_per_packet /=
542			s->cfg.frame_size * inurb->number_of_packets;
543		frames_per_packet++;
544
545		max_diff_0 = s->cfg.frame_size;
546		if (s->cfg.period_frames >= 256)
547			max_diff_0 <<= 1;
548		if (s->cfg.period_frames >= 1024)
549			max_diff_0 <<= 1;
550		max_diff = max_diff_0;
551		for (p = 0; p < inurb->number_of_packets; ++p) {
552			int diff;
553
554			l = inurb->iso_frame_desc[p].actual_length;
555			urb_size += l;
556
557			min_frames += frames_per_packet;
558			diff = urb_size -
559				(min_frames >> 8) * s->cfg.frame_size;
560			if (diff < max_diff)
561				max_diff = diff;
562		}
563		s->idle_insize -= max_diff - max_diff_0;
564		s->idle_insize += urb_size - s->period_size;
565		if (s->idle_insize < 0) {
566			dev_warn(&sk->dev->dev, "%s idle_insize: %i %i %i\n",
567				 __func__,
568				 s->idle_insize, urb_size, s->period_size);
569			return;
570		} else if (s->idle_insize == 0) {
571			s->next_inpacket_split =
572				(s->inpacket_head + 1) % s->inpackets;
573			s->next_inpacket_split_at = 0;
574		} else {
575			unsigned int split = s->inpacket_head;
576
577			l = s->idle_insize;
578			while (l > s->inpacket[split].length) {
579				l -= s->inpacket[split].length;
580				if (split == 0)
581					split = s->inpackets - 1;
582				else
583					split--;
584			}
585			s->next_inpacket_split = split;
586			s->next_inpacket_split_at =
587				s->inpacket[split].length - l;
588		}
589
590		s->insize_done += urb_size;
591
592		if (usb_stream_prepare_playback(sk, inurb) < 0)
593			return;
594
595	} else
596		playback_prep_freqn(sk, sk->idle_outurb);
597
598	if (submit_urbs(sk, inurb, outurb) < 0)
599		return;
600
601	if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
602		/* just guesswork                            ^^^^^^ */
603		s->state = usb_stream_ready;
604		subs_set_complete(sk->inurb, i_capture_idle);
605		subs_set_complete(sk->outurb, i_playback_idle);
606	}
607}
608
609static void i_capture_start(struct urb *urb)
610{
611	struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
612	struct usb_stream_kernel *sk = urb->context;
613	struct usb_stream *s = sk->s;
614	int p;
615	int empty = 0;
616
617	if (urb->status) {
618		dev_warn(&sk->dev->dev, "%s: status=%i\n", __func__, urb->status);
619		return;
620	}
621
622	for (p = 0; p < urb->number_of_packets; ++p) {
623		int l = id[p].actual_length;
624
625		if (l < s->cfg.frame_size) {
626			++empty;
627			if (s->state >= usb_stream_sync0) {
628				dev_warn(&sk->dev->dev, "%s: length %i\n", __func__, l);
629				return;
630			}
631		}
632		s->inpacket_head++;
633		s->inpacket_head %= s->inpackets;
634		s->inpacket[s->inpacket_head].offset =
635			id[p].offset + (urb->transfer_buffer - (void *)s);
636		s->inpacket[s->inpacket_head].length = l;
637	}
638#ifdef SHOW_EMPTY
639	if (empty) {
640		dev_dbg(&sk->dev->dev, "%s:%i: %i", __func__, __LINE__,
641			urb->iso_frame_desc[0].actual_length);
642		for (pack = 1; pack < urb->number_of_packets; ++pack) {
643			int l = urb->iso_frame_desc[pack].actual_length;
644
645			printk(KERN_CONT " %i", l);
646		}
647		printk(KERN_CONT "\n");
648	}
649#endif
650	if (!empty && s->state < usb_stream_sync1)
651		++s->state;
652
653	if (balance_capture(sk, urb))
654		stream_start(sk, urb, sk->i_urb);
655}
656
657static void i_playback_start(struct urb *urb)
658{
659	struct usb_stream_kernel *sk = urb->context;
660
661	if (balance_playback(sk, urb))
662		stream_start(sk, sk->i_urb, urb);
663}
664
665int usb_stream_start(struct usb_stream_kernel *sk)
666{
667	struct usb_stream *s = sk->s;
668	int frame = 0;
669	int u, err;
670	int try = 0;
671
672	if (s->state != usb_stream_stopped)
673		return -EAGAIN;
674
675	subs_set_complete(sk->inurb, i_capture_start);
676	subs_set_complete(sk->outurb, i_playback_start);
677	memset(sk->write_page, 0, s->write_size);
678dotry:
679	s->insize_done = 0;
680	s->idle_insize = 0;
681	s->idle_outsize = 0;
682	s->sync_packet = -1;
683	s->inpacket_head = -1;
684	sk->iso_frame_balance = 0;
685	++try;
686	for (u = 0; u < 2; u++) {
687		struct urb *inurb = sk->inurb[u];
688		struct urb *outurb = sk->outurb[u];
689
690		playback_prep_freqn(sk, outurb);
691		inurb->number_of_packets = outurb->number_of_packets;
692		inurb->transfer_buffer_length =
693			inurb->number_of_packets *
694			inurb->iso_frame_desc[0].length;
695
696		if (u == 0) {
697			int now;
698			struct usb_device *dev = inurb->dev;
699
700			frame = usb_get_current_frame_number(dev);
701			do {
702				now = usb_get_current_frame_number(dev);
703			} while (now > -1 && now == frame);
704		}
705		err = usb_submit_urb(inurb, GFP_ATOMIC);
706		if (err < 0) {
707			dev_err(&sk->dev->dev,
708				"%s: usb_submit_urb(sk->inurb[%i]) returned %i\n",
709				__func__, u, err);
710			return err;
711		}
712		err = usb_submit_urb(outurb, GFP_ATOMIC);
713		if (err < 0) {
714			dev_err(&sk->dev->dev,
715				"%s: usb_submit_urb(sk->outurb[%i]) returned %i\n",
716				__func__, u, err);
717			return err;
718		}
719
720		if (inurb->start_frame != outurb->start_frame) {
721			dev_dbg(&sk->dev->dev,
722				"%s: u[%i] start_frames differ in:%u out:%u\n",
723				__func__, u, inurb->start_frame, outurb->start_frame);
724			goto check_retry;
725		}
726	}
727	try = 0;
728check_retry:
729	if (try) {
730		usb_stream_stop(sk);
731		if (try < 5) {
732			msleep(1500);
733			dev_dbg(&sk->dev->dev, "goto dotry;\n");
734			goto dotry;
735		}
736		dev_warn(&sk->dev->dev,
737			 "%s: couldn't start all urbs on the same start_frame.\n",
738			 __func__);
739		return -EFAULT;
740	}
741
742	sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
743	sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
744	sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
745	sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
746
747/* wait, check */
748	{
749		int wait_ms = 3000;
750
751		while (s->state != usb_stream_ready && wait_ms > 0) {
752			msleep(200);
753			wait_ms -= 200;
754		}
755	}
756
757	return s->state == usb_stream_ready ? 0 : -EFAULT;
758}
759
760
761/*                             stop                                   */
762
763void usb_stream_stop(struct usb_stream_kernel *sk)
764{
765	int u;
766
767	if (!sk->s)
768		return;
769	for (u = 0; u < USB_STREAM_NURBS; ++u) {
770		usb_kill_urb(sk->inurb[u]);
771		usb_kill_urb(sk->outurb[u]);
772	}
773	sk->s->state = usb_stream_stopped;
774	msleep(400);
775}
~/ Read-only file preview.