xref: /openbmc/linux/sound/usb/usx2y/usb_stream.c (revision 5a244f48)
1 /*
2  * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or (at your
7  * option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 #include <linux/usb.h>
20 #include <linux/gfp.h>
21 
22 #include "usb_stream.h"
23 
24 
25 /*                             setup                                  */
26 
27 static unsigned usb_stream_next_packet_size(struct usb_stream_kernel *sk)
28 {
29 	struct usb_stream *s = sk->s;
30 	sk->out_phase_peeked = (sk->out_phase & 0xffff) + sk->freqn;
31 	return (sk->out_phase_peeked >> 16) * s->cfg.frame_size;
32 }
33 
34 static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb)
35 {
36 	struct usb_stream *s = sk->s;
37 	int pack, lb = 0;
38 
39 	for (pack = 0; pack < sk->n_o_ps; pack++) {
40 		int l = usb_stream_next_packet_size(sk);
41 		if (s->idle_outsize + lb + l > s->period_size)
42 			goto check;
43 
44 		sk->out_phase = sk->out_phase_peeked;
45 		urb->iso_frame_desc[pack].offset = lb;
46 		urb->iso_frame_desc[pack].length = l;
47 		lb += l;
48 	}
49 	snd_printdd(KERN_DEBUG "%i\n", lb);
50 
51 check:
52 	urb->number_of_packets = pack;
53 	urb->transfer_buffer_length = lb;
54 	s->idle_outsize += lb - s->period_size;
55 	snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
56 		    lb, s->period_size);
57 }
58 
59 static void init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
60 			   struct urb **urbs, char *transfer,
61 			   struct usb_device *dev, int pipe)
62 {
63 	int u, p;
64 	int maxpacket = use_packsize ?
65 		use_packsize : usb_maxpacket(dev, pipe, usb_pipeout(pipe));
66 	int transfer_length = maxpacket * sk->n_o_ps;
67 
68 	for (u = 0; u < USB_STREAM_NURBS;
69 	     ++u, transfer += transfer_length) {
70 		struct urb *urb = urbs[u];
71 		struct usb_iso_packet_descriptor *desc;
72 		urb->transfer_buffer = transfer;
73 		urb->dev = dev;
74 		urb->pipe = pipe;
75 		urb->number_of_packets = sk->n_o_ps;
76 		urb->context = sk;
77 		urb->interval = 1;
78 		if (usb_pipeout(pipe))
79 			continue;
80 
81 		urb->transfer_buffer_length = transfer_length;
82 		desc = urb->iso_frame_desc;
83 		desc->offset = 0;
84 		desc->length = maxpacket;
85 		for (p = 1; p < sk->n_o_ps; ++p) {
86 			desc[p].offset = desc[p - 1].offset + maxpacket;
87 			desc[p].length = maxpacket;
88 		}
89 	}
90 }
91 
92 static void init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
93 		      struct usb_device *dev, int in_pipe, int out_pipe)
94 {
95 	struct usb_stream	*s = sk->s;
96 	char			*indata = (char *)s + sizeof(*s) +
97 					sizeof(struct usb_stream_packet) *
98 					s->inpackets;
99 	int			u;
100 
101 	for (u = 0; u < USB_STREAM_NURBS; ++u) {
102 		sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
103 		sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
104 	}
105 
106 	init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe);
107 	init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
108 		       out_pipe);
109 }
110 
111 
112 /*
113  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
114  * this will overflow at approx 524 kHz
115  */
116 static inline unsigned get_usb_full_speed_rate(unsigned rate)
117 {
118 	return ((rate << 13) + 62) / 125;
119 }
120 
121 /*
122  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
123  * this will overflow at approx 4 MHz
124  */
125 static inline unsigned get_usb_high_speed_rate(unsigned rate)
126 {
127 	return ((rate << 10) + 62) / 125;
128 }
129 
130 void usb_stream_free(struct usb_stream_kernel *sk)
131 {
132 	struct usb_stream *s;
133 	unsigned u;
134 
135 	for (u = 0; u < USB_STREAM_NURBS; ++u) {
136 		usb_free_urb(sk->inurb[u]);
137 		sk->inurb[u] = NULL;
138 		usb_free_urb(sk->outurb[u]);
139 		sk->outurb[u] = NULL;
140 	}
141 
142 	s = sk->s;
143 	if (!s)
144 		return;
145 
146 	free_pages((unsigned long)sk->write_page, get_order(s->write_size));
147 	sk->write_page = NULL;
148 	free_pages((unsigned long)s, get_order(s->read_size));
149 	sk->s = NULL;
150 }
151 
152 struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
153 				  struct usb_device *dev,
154 				  unsigned in_endpoint, unsigned out_endpoint,
155 				  unsigned sample_rate, unsigned use_packsize,
156 				  unsigned period_frames, unsigned frame_size)
157 {
158 	int packets, max_packsize;
159 	int in_pipe, out_pipe;
160 	int read_size = sizeof(struct usb_stream);
161 	int write_size;
162 	int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
163 	int pg;
164 
165 	in_pipe = usb_rcvisocpipe(dev, in_endpoint);
166 	out_pipe = usb_sndisocpipe(dev, out_endpoint);
167 
168 	max_packsize = use_packsize ?
169 		use_packsize : usb_maxpacket(dev, in_pipe, 0);
170 
171 	/*
172 		t_period = period_frames / sample_rate
173 		iso_packs = t_period / t_iso_frame
174 			= (period_frames / sample_rate) * (1 / t_iso_frame)
175 	*/
176 
177 	packets = period_frames * usb_frames / sample_rate + 1;
178 
179 	if (dev->speed == USB_SPEED_HIGH)
180 		packets = (packets + 7) & ~7;
181 
182 	read_size += packets * USB_STREAM_URBDEPTH *
183 		(max_packsize + sizeof(struct usb_stream_packet));
184 
185 	max_packsize = usb_maxpacket(dev, out_pipe, 1);
186 	write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
187 
188 	if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
189 		snd_printk(KERN_WARNING "a size exceeds 128*PAGE_SIZE\n");
190 		goto out;
191 	}
192 
193 	pg = get_order(read_size);
194 	sk->s = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO|
195 					  __GFP_NOWARN, pg);
196 	if (!sk->s) {
197 		snd_printk(KERN_WARNING "couldn't __get_free_pages()\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 	pg = get_order(write_size);
213 
214 	sk->write_page =
215 		(void *)__get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO|
216 					 __GFP_NOWARN, pg);
217 	if (!sk->write_page) {
218 		snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
219 		usb_stream_free(sk);
220 		return NULL;
221 	}
222 
223 	/* calculate the frequency in 16.16 format */
224 	if (dev->speed == USB_SPEED_FULL)
225 		sk->freqn = get_usb_full_speed_rate(sample_rate);
226 	else
227 		sk->freqn = get_usb_high_speed_rate(sample_rate);
228 
229 	init_urbs(sk, use_packsize, dev, in_pipe, out_pipe);
230 	sk->s->state = usb_stream_stopped;
231 out:
232 	return sk->s;
233 }
234 
235 
236 /*                             start                                  */
237 
238 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
239 {
240 	bool r;
241 	if (unlikely(urb->status)) {
242 		if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
243 			snd_printk(KERN_WARNING "status=%i\n", urb->status);
244 		sk->iso_frame_balance = 0x7FFFFFFF;
245 		return false;
246 	}
247 	r = sk->iso_frame_balance == 0;
248 	if (!r)
249 		sk->i_urb = urb;
250 	return r;
251 }
252 
253 static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
254 {
255 	sk->iso_frame_balance += urb->number_of_packets;
256 	return balance_check(sk, urb);
257 }
258 
259 static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
260 {
261 	sk->iso_frame_balance -= urb->number_of_packets;
262 	return balance_check(sk, urb);
263 }
264 
265 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
266 {
267 	int u;
268 
269 	for (u = 0; u < USB_STREAM_NURBS; u++) {
270 		struct urb *urb = urbs[u];
271 		urb->complete = complete;
272 	}
273 }
274 
275 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
276 		struct urb *inurb)
277 {
278 	struct usb_stream *s = sk->s;
279 	struct urb *io;
280 	struct usb_iso_packet_descriptor *id, *od;
281 	int p = 0, lb = 0, l = 0;
282 
283 	io = sk->idle_outurb;
284 	od = io->iso_frame_desc;
285 
286 	for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
287 		struct urb *ii = sk->completed_inurb;
288 		id = ii->iso_frame_desc +
289 			ii->number_of_packets + s->sync_packet;
290 		l = id->actual_length;
291 
292 		od[p].length = l;
293 		od[p].offset = lb;
294 		lb += l;
295 	}
296 
297 	for (;
298 	     s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
299 	     ++p, ++s->sync_packet) {
300 		l = inurb->iso_frame_desc[s->sync_packet].actual_length;
301 
302 		if (s->idle_outsize + lb + l > s->period_size)
303 			goto check_ok;
304 
305 		od[p].length = l;
306 		od[p].offset = lb;
307 		lb += l;
308 	}
309 
310 check_ok:
311 	s->sync_packet -= inurb->number_of_packets;
312 	if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
313 		snd_printk(KERN_WARNING "invalid sync_packet = %i;"
314 			   " p=%i nop=%i %i %x %x %x > %x\n",
315 			   s->sync_packet, p, inurb->number_of_packets,
316 			   s->idle_outsize + lb + l,
317 			   s->idle_outsize, lb,  l,
318 			   s->period_size);
319 		return -1;
320 	}
321 	if (unlikely(lb % s->cfg.frame_size)) {
322 		snd_printk(KERN_WARNING"invalid outsize = %i\n",
323 			   lb);
324 		return -1;
325 	}
326 	s->idle_outsize += lb - s->period_size;
327 	io->number_of_packets = p;
328 	io->transfer_buffer_length = lb;
329 	if (s->idle_outsize <= 0)
330 		return 0;
331 
332 	snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
333 	return -1;
334 }
335 
336 static void prepare_inurb(int number_of_packets, struct urb *iu)
337 {
338 	struct usb_iso_packet_descriptor *id;
339 	int p;
340 
341 	iu->number_of_packets = number_of_packets;
342 	id = iu->iso_frame_desc;
343 	id->offset = 0;
344 	for (p = 0; p < iu->number_of_packets - 1; ++p)
345 		id[p + 1].offset = id[p].offset + id[p].length;
346 
347 	iu->transfer_buffer_length =
348 		id[0].length * iu->number_of_packets;
349 }
350 
351 static int submit_urbs(struct usb_stream_kernel *sk,
352 		       struct urb *inurb, struct urb *outurb)
353 {
354 	int err;
355 	prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
356 	err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
357 	if (err < 0)
358 		goto report_failure;
359 
360 	sk->idle_inurb = sk->completed_inurb;
361 	sk->completed_inurb = inurb;
362 	err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
363 	if (err < 0)
364 		goto report_failure;
365 
366 	sk->idle_outurb = sk->completed_outurb;
367 	sk->completed_outurb = outurb;
368 	return 0;
369 
370 report_failure:
371 	snd_printk(KERN_ERR "%i\n", err);
372 	return err;
373 }
374 
375 #ifdef DEBUG_LOOP_BACK
376 /*
377   This loop_back() shows how to read/write the period data.
378  */
379 static void loop_back(struct usb_stream *s)
380 {
381 	char *i, *o;
382 	int il, ol, l, p;
383 	struct urb *iu;
384 	struct usb_iso_packet_descriptor *id;
385 
386 	o = s->playback1st_to;
387 	ol = s->playback1st_size;
388 	l = 0;
389 
390 	if (s->insplit_pack >= 0) {
391 		iu = sk->idle_inurb;
392 		id = iu->iso_frame_desc;
393 		p = s->insplit_pack;
394 	} else
395 		goto second;
396 loop:
397 	for (; p < iu->number_of_packets && l < s->period_size; ++p) {
398 		i = iu->transfer_buffer + id[p].offset;
399 		il = id[p].actual_length;
400 		if (l + il > s->period_size)
401 			il = s->period_size - l;
402 		if (il <= ol) {
403 			memcpy(o, i, il);
404 			o += il;
405 			ol -= il;
406 		} else {
407 			memcpy(o, i, ol);
408 			singen_6pack(o, ol);
409 			o = s->playback_to;
410 			memcpy(o, i + ol, il - ol);
411 			o += il - ol;
412 			ol = s->period_size - s->playback1st_size;
413 		}
414 		l += il;
415 	}
416 	if (iu == sk->completed_inurb) {
417 		if (l != s->period_size)
418 			printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
419 			       l/(int)s->cfg.frame_size);
420 
421 		return;
422 	}
423 second:
424 	iu = sk->completed_inurb;
425 	id = iu->iso_frame_desc;
426 	p = 0;
427 	goto loop;
428 
429 }
430 #else
431 static void loop_back(struct usb_stream *s)
432 {
433 }
434 #endif
435 
436 static void stream_idle(struct usb_stream_kernel *sk,
437 			struct urb *inurb, struct urb *outurb)
438 {
439 	struct usb_stream *s = sk->s;
440 	int l, p;
441 	int insize = s->idle_insize;
442 	int urb_size = 0;
443 
444 	s->inpacket_split = s->next_inpacket_split;
445 	s->inpacket_split_at = s->next_inpacket_split_at;
446 	s->next_inpacket_split = -1;
447 	s->next_inpacket_split_at = 0;
448 
449 	for (p = 0; p < inurb->number_of_packets; ++p) {
450 		struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
451 		l = id[p].actual_length;
452 		if (unlikely(l == 0 || id[p].status)) {
453 			snd_printk(KERN_WARNING "underrun, status=%u\n",
454 				   id[p].status);
455 			goto err_out;
456 		}
457 		s->inpacket_head++;
458 		s->inpacket_head %= s->inpackets;
459 		if (s->inpacket_split == -1)
460 			s->inpacket_split = s->inpacket_head;
461 
462 		s->inpacket[s->inpacket_head].offset =
463 			id[p].offset + (inurb->transfer_buffer - (void *)s);
464 		s->inpacket[s->inpacket_head].length = l;
465 		if (insize + l > s->period_size &&
466 		    s->next_inpacket_split == -1) {
467 			s->next_inpacket_split = s->inpacket_head;
468 			s->next_inpacket_split_at = s->period_size - insize;
469 		}
470 		insize += l;
471 		urb_size += l;
472 	}
473 	s->idle_insize += urb_size - s->period_size;
474 	if (s->idle_insize < 0) {
475 		snd_printk(KERN_WARNING "%i\n",
476 			   (s->idle_insize)/(int)s->cfg.frame_size);
477 		goto err_out;
478 	}
479 	s->insize_done += urb_size;
480 
481 	l = s->idle_outsize;
482 	s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
483 				  sk->write_page) - l;
484 
485 	if (usb_stream_prepare_playback(sk, inurb) < 0)
486 		goto err_out;
487 
488 	s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
489 	s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
490 		sk->write_page;
491 
492 	if (submit_urbs(sk, inurb, outurb) < 0)
493 		goto err_out;
494 
495 	loop_back(s);
496 	s->periods_done++;
497 	wake_up_all(&sk->sleep);
498 	return;
499 err_out:
500 	s->state = usb_stream_xrun;
501 	wake_up_all(&sk->sleep);
502 }
503 
504 static void i_capture_idle(struct urb *urb)
505 {
506 	struct usb_stream_kernel *sk = urb->context;
507 	if (balance_capture(sk, urb))
508 		stream_idle(sk, urb, sk->i_urb);
509 }
510 
511 static void i_playback_idle(struct urb *urb)
512 {
513 	struct usb_stream_kernel *sk = urb->context;
514 	if (balance_playback(sk, urb))
515 		stream_idle(sk, sk->i_urb, urb);
516 }
517 
518 static void stream_start(struct usb_stream_kernel *sk,
519 			 struct urb *inurb, struct urb *outurb)
520 {
521 	struct usb_stream *s = sk->s;
522 	if (s->state >= usb_stream_sync1) {
523 		int l, p, max_diff, max_diff_0;
524 		int urb_size = 0;
525 		unsigned frames_per_packet, min_frames = 0;
526 		frames_per_packet = (s->period_size - s->idle_insize);
527 		frames_per_packet <<= 8;
528 		frames_per_packet /=
529 			s->cfg.frame_size * inurb->number_of_packets;
530 		frames_per_packet++;
531 
532 		max_diff_0 = s->cfg.frame_size;
533 		if (s->cfg.period_frames >= 256)
534 			max_diff_0 <<= 1;
535 		if (s->cfg.period_frames >= 1024)
536 			max_diff_0 <<= 1;
537 		max_diff = max_diff_0;
538 		for (p = 0; p < inurb->number_of_packets; ++p) {
539 			int diff;
540 			l = inurb->iso_frame_desc[p].actual_length;
541 			urb_size += l;
542 
543 			min_frames += frames_per_packet;
544 			diff = urb_size -
545 				(min_frames >> 8) * s->cfg.frame_size;
546 			if (diff < max_diff) {
547 				snd_printdd(KERN_DEBUG "%i %i %i %i\n",
548 					    s->insize_done,
549 					    urb_size / (int)s->cfg.frame_size,
550 					    inurb->number_of_packets, diff);
551 				max_diff = diff;
552 			}
553 		}
554 		s->idle_insize -= max_diff - max_diff_0;
555 		s->idle_insize += urb_size - s->period_size;
556 		if (s->idle_insize < 0) {
557 			snd_printk(KERN_WARNING "%i %i %i\n",
558 				   s->idle_insize, urb_size, s->period_size);
559 			return;
560 		} else if (s->idle_insize == 0) {
561 			s->next_inpacket_split =
562 				(s->inpacket_head + 1) % s->inpackets;
563 			s->next_inpacket_split_at = 0;
564 		} else {
565 			unsigned split = s->inpacket_head;
566 			l = s->idle_insize;
567 			while (l > s->inpacket[split].length) {
568 				l -= s->inpacket[split].length;
569 				if (split == 0)
570 					split = s->inpackets - 1;
571 				else
572 					split--;
573 			}
574 			s->next_inpacket_split = split;
575 			s->next_inpacket_split_at =
576 				s->inpacket[split].length - l;
577 		}
578 
579 		s->insize_done += urb_size;
580 
581 		if (usb_stream_prepare_playback(sk, inurb) < 0)
582 			return;
583 
584 	} else
585 		playback_prep_freqn(sk, sk->idle_outurb);
586 
587 	if (submit_urbs(sk, inurb, outurb) < 0)
588 		return;
589 
590 	if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
591 		/* just guesswork                            ^^^^^^ */
592 		s->state = usb_stream_ready;
593 		subs_set_complete(sk->inurb, i_capture_idle);
594 		subs_set_complete(sk->outurb, i_playback_idle);
595 	}
596 }
597 
598 static void i_capture_start(struct urb *urb)
599 {
600 	struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
601 	struct usb_stream_kernel *sk = urb->context;
602 	struct usb_stream *s = sk->s;
603 	int p;
604 	int empty = 0;
605 
606 	if (urb->status) {
607 		snd_printk(KERN_WARNING "status=%i\n", urb->status);
608 		return;
609 	}
610 
611 	for (p = 0; p < urb->number_of_packets; ++p) {
612 		int l = id[p].actual_length;
613 		if (l < s->cfg.frame_size) {
614 			++empty;
615 			if (s->state >= usb_stream_sync0) {
616 				snd_printk(KERN_WARNING "%i\n", l);
617 				return;
618 			}
619 		}
620 		s->inpacket_head++;
621 		s->inpacket_head %= s->inpackets;
622 		s->inpacket[s->inpacket_head].offset =
623 			id[p].offset + (urb->transfer_buffer - (void *)s);
624 		s->inpacket[s->inpacket_head].length = l;
625 	}
626 #ifdef SHOW_EMPTY
627 	if (empty) {
628 		printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
629 		       urb->iso_frame_desc[0].actual_length);
630 		for (pack = 1; pack < urb->number_of_packets; ++pack) {
631 			int l = urb->iso_frame_desc[pack].actual_length;
632 			printk(KERN_CONT " %i", l);
633 		}
634 		printk(KERN_CONT "\n");
635 	}
636 #endif
637 	if (!empty && s->state < usb_stream_sync1)
638 		++s->state;
639 
640 	if (balance_capture(sk, urb))
641 		stream_start(sk, urb, sk->i_urb);
642 }
643 
644 static void i_playback_start(struct urb *urb)
645 {
646 	struct usb_stream_kernel *sk = urb->context;
647 	if (balance_playback(sk, urb))
648 		stream_start(sk, sk->i_urb, urb);
649 }
650 
651 int usb_stream_start(struct usb_stream_kernel *sk)
652 {
653 	struct usb_stream *s = sk->s;
654 	int frame = 0, iters = 0;
655 	int u, err;
656 	int try = 0;
657 
658 	if (s->state != usb_stream_stopped)
659 		return -EAGAIN;
660 
661 	subs_set_complete(sk->inurb, i_capture_start);
662 	subs_set_complete(sk->outurb, i_playback_start);
663 	memset(sk->write_page, 0, s->write_size);
664 dotry:
665 	s->insize_done = 0;
666 	s->idle_insize = 0;
667 	s->idle_outsize = 0;
668 	s->sync_packet = -1;
669 	s->inpacket_head = -1;
670 	sk->iso_frame_balance = 0;
671 	++try;
672 	for (u = 0; u < 2; u++) {
673 		struct urb *inurb = sk->inurb[u];
674 		struct urb *outurb = sk->outurb[u];
675 		playback_prep_freqn(sk, outurb);
676 		inurb->number_of_packets = outurb->number_of_packets;
677 		inurb->transfer_buffer_length =
678 			inurb->number_of_packets *
679 			inurb->iso_frame_desc[0].length;
680 
681 		if (u == 0) {
682 			int now;
683 			struct usb_device *dev = inurb->dev;
684 			frame = usb_get_current_frame_number(dev);
685 			do {
686 				now = usb_get_current_frame_number(dev);
687 				++iters;
688 			} while (now > -1 && now == frame);
689 		}
690 		err = usb_submit_urb(inurb, GFP_ATOMIC);
691 		if (err < 0) {
692 			snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
693 				   " returned %i\n", u, err);
694 			return err;
695 		}
696 		err = usb_submit_urb(outurb, GFP_ATOMIC);
697 		if (err < 0) {
698 			snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
699 				   " returned %i\n", u, err);
700 			return err;
701 		}
702 
703 		if (inurb->start_frame != outurb->start_frame) {
704 			snd_printd(KERN_DEBUG
705 				   "u[%i] start_frames differ in:%u out:%u\n",
706 				   u, inurb->start_frame, outurb->start_frame);
707 			goto check_retry;
708 		}
709 	}
710 	snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
711 	try = 0;
712 check_retry:
713 	if (try) {
714 		usb_stream_stop(sk);
715 		if (try < 5) {
716 			msleep(1500);
717 			snd_printd(KERN_DEBUG "goto dotry;\n");
718 			goto dotry;
719 		}
720 		snd_printk(KERN_WARNING"couldn't start"
721 			   " all urbs on the same start_frame.\n");
722 		return -EFAULT;
723 	}
724 
725 	sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
726 	sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
727 	sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
728 	sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
729 
730 /* wait, check */
731 	{
732 		int wait_ms = 3000;
733 		while (s->state != usb_stream_ready && wait_ms > 0) {
734 			snd_printdd(KERN_DEBUG "%i\n", s->state);
735 			msleep(200);
736 			wait_ms -= 200;
737 		}
738 	}
739 
740 	return s->state == usb_stream_ready ? 0 : -EFAULT;
741 }
742 
743 
744 /*                             stop                                   */
745 
746 void usb_stream_stop(struct usb_stream_kernel *sk)
747 {
748 	int u;
749 	if (!sk->s)
750 		return;
751 	for (u = 0; u < USB_STREAM_NURBS; ++u) {
752 		usb_kill_urb(sk->inurb[u]);
753 		usb_kill_urb(sk->outurb[u]);
754 	}
755 	sk->s->state = usb_stream_stopped;
756 	msleep(400);
757 }
758