GNU Linux-libre 6.9.1-gnu
[releases.git] / sound / usb / usx2y / usb_stream.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
13 static 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
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
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         snd_printdd(KERN_DEBUG "%i\n", lb);
38
39 check:
40         urb->number_of_packets = pack;
41         urb->transfer_buffer_length = lb;
42         s->idle_outsize += lb - s->period_size;
43         snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
44                     lb, s->period_size);
45 }
46
47 static int init_pipe_urbs(struct usb_stream_kernel *sk,
48                           unsigned int use_packsize,
49                           struct urb **urbs, char *transfer,
50                           struct usb_device *dev, int pipe)
51 {
52         int u, p;
53         int maxpacket = use_packsize ?
54                 use_packsize : usb_maxpacket(dev, pipe);
55         int transfer_length = maxpacket * sk->n_o_ps;
56
57         for (u = 0; u < USB_STREAM_NURBS;
58              ++u, transfer += transfer_length) {
59                 struct urb *urb = urbs[u];
60                 struct usb_iso_packet_descriptor *desc;
61
62                 urb->transfer_buffer = transfer;
63                 urb->dev = dev;
64                 urb->pipe = pipe;
65                 urb->number_of_packets = sk->n_o_ps;
66                 urb->context = sk;
67                 urb->interval = 1;
68                 if (usb_pipeout(pipe))
69                         continue;
70                 if (usb_urb_ep_type_check(urb))
71                         return -EINVAL;
72
73                 urb->transfer_buffer_length = transfer_length;
74                 desc = urb->iso_frame_desc;
75                 desc->offset = 0;
76                 desc->length = maxpacket;
77                 for (p = 1; p < sk->n_o_ps; ++p) {
78                         desc[p].offset = desc[p - 1].offset + maxpacket;
79                         desc[p].length = maxpacket;
80                 }
81         }
82
83         return 0;
84 }
85
86 static int init_urbs(struct usb_stream_kernel *sk, unsigned int use_packsize,
87                      struct usb_device *dev, int in_pipe, int out_pipe)
88 {
89         struct usb_stream       *s = sk->s;
90         char                    *indata =
91                 (char *)s + sizeof(*s) + sizeof(struct usb_stream_packet) * s->inpackets;
92         int                     u;
93
94         for (u = 0; u < USB_STREAM_NURBS; ++u) {
95                 sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
96                 if (!sk->inurb[u])
97                         return -ENOMEM;
98
99                 sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
100                 if (!sk->outurb[u])
101                         return -ENOMEM;
102         }
103
104         if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
105             init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
106                            out_pipe))
107                 return -EINVAL;
108
109         return 0;
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 int get_usb_full_speed_rate(unsigned int 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 int get_usb_high_speed_rate(unsigned int 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 int 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         if (sk->write_page) {
147                 free_pages_exact(sk->write_page, s->write_size);
148                 sk->write_page = NULL;
149         }
150
151         free_pages_exact(s, s->read_size);
152         sk->s = NULL;
153 }
154
155 struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
156                                   struct usb_device *dev,
157                                   unsigned int in_endpoint,
158                                   unsigned int out_endpoint,
159                                   unsigned int sample_rate,
160                                   unsigned int use_packsize,
161                                   unsigned int period_frames,
162                                   unsigned int frame_size)
163 {
164         int packets, max_packsize;
165         int in_pipe, out_pipe;
166         int read_size = sizeof(struct usb_stream);
167         int write_size;
168         int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
169
170         in_pipe = usb_rcvisocpipe(dev, in_endpoint);
171         out_pipe = usb_sndisocpipe(dev, out_endpoint);
172
173         max_packsize = use_packsize ?
174                 use_packsize : usb_maxpacket(dev, in_pipe);
175
176         /*
177                 t_period = period_frames / sample_rate
178                 iso_packs = t_period / t_iso_frame
179                         = (period_frames / sample_rate) * (1 / t_iso_frame)
180         */
181
182         packets = period_frames * usb_frames / sample_rate + 1;
183
184         if (dev->speed == USB_SPEED_HIGH)
185                 packets = (packets + 7) & ~7;
186
187         read_size += packets * USB_STREAM_URBDEPTH *
188                 (max_packsize + sizeof(struct usb_stream_packet));
189
190         max_packsize = usb_maxpacket(dev, out_pipe);
191         write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
192
193         if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
194                 snd_printk(KERN_WARNING "a size exceeds 128*PAGE_SIZE\n");
195                 goto out;
196         }
197
198         sk->s = alloc_pages_exact(read_size,
199                                   GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
200         if (!sk->s) {
201                 pr_warn("us122l: couldn't allocate read buffer\n");
202                 goto out;
203         }
204         sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
205
206         sk->s->read_size = read_size;
207
208         sk->s->cfg.sample_rate = sample_rate;
209         sk->s->cfg.frame_size = frame_size;
210         sk->n_o_ps = packets;
211         sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
212         sk->s->cfg.period_frames = period_frames;
213         sk->s->period_size = frame_size * period_frames;
214
215         sk->s->write_size = write_size;
216
217         sk->write_page = alloc_pages_exact(write_size,
218                                            GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
219         if (!sk->write_page) {
220                 pr_warn("us122l: couldn't allocate write buffer\n");
221                 usb_stream_free(sk);
222                 return NULL;
223         }
224
225         /* calculate the frequency in 16.16 format */
226         if (dev->speed == USB_SPEED_FULL)
227                 sk->freqn = get_usb_full_speed_rate(sample_rate);
228         else
229                 sk->freqn = get_usb_high_speed_rate(sample_rate);
230
231         if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
232                 usb_stream_free(sk);
233                 return NULL;
234         }
235
236         sk->s->state = usb_stream_stopped;
237 out:
238         return sk->s;
239 }
240
241 /*                             start                                  */
242
243 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
244 {
245         bool r;
246
247         if (unlikely(urb->status)) {
248                 if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
249                         snd_printk(KERN_WARNING "status=%i\n", urb->status);
250                 sk->iso_frame_balance = 0x7FFFFFFF;
251                 return false;
252         }
253         r = sk->iso_frame_balance == 0;
254         if (!r)
255                 sk->i_urb = urb;
256         return r;
257 }
258
259 static bool balance_playback(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 bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
266 {
267         sk->iso_frame_balance -= urb->number_of_packets;
268         return balance_check(sk, urb);
269 }
270
271 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
272 {
273         int u;
274
275         for (u = 0; u < USB_STREAM_NURBS; u++) {
276                 struct urb *urb = urbs[u];
277
278                 urb->complete = complete;
279         }
280 }
281
282 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
283                 struct urb *inurb)
284 {
285         struct usb_stream *s = sk->s;
286         struct urb *io;
287         struct usb_iso_packet_descriptor *id, *od;
288         int p = 0, lb = 0, l = 0;
289
290         io = sk->idle_outurb;
291         od = io->iso_frame_desc;
292
293         for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
294                 struct urb *ii = sk->completed_inurb;
295
296                 id = ii->iso_frame_desc +
297                         ii->number_of_packets + s->sync_packet;
298                 l = id->actual_length;
299
300                 od[p].length = l;
301                 od[p].offset = lb;
302                 lb += l;
303         }
304
305         for (;
306              s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
307              ++p, ++s->sync_packet) {
308                 l = inurb->iso_frame_desc[s->sync_packet].actual_length;
309
310                 if (s->idle_outsize + lb + l > s->period_size)
311                         goto check_ok;
312
313                 od[p].length = l;
314                 od[p].offset = lb;
315                 lb += l;
316         }
317
318 check_ok:
319         s->sync_packet -= inurb->number_of_packets;
320         if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
321                 snd_printk(KERN_WARNING "invalid sync_packet = %i;"
322                            " p=%i nop=%i %i %x %x %x > %x\n",
323                            s->sync_packet, p, inurb->number_of_packets,
324                            s->idle_outsize + lb + l,
325                            s->idle_outsize, lb,  l,
326                            s->period_size);
327                 return -1;
328         }
329         if (unlikely(lb % s->cfg.frame_size)) {
330                 snd_printk(KERN_WARNING"invalid outsize = %i\n",
331                            lb);
332                 return -1;
333         }
334         s->idle_outsize += lb - s->period_size;
335         io->number_of_packets = p;
336         io->transfer_buffer_length = lb;
337         if (s->idle_outsize <= 0)
338                 return 0;
339
340         snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
341         return -1;
342 }
343
344 static void prepare_inurb(int number_of_packets, struct urb *iu)
345 {
346         struct usb_iso_packet_descriptor *id;
347         int p;
348
349         iu->number_of_packets = number_of_packets;
350         id = iu->iso_frame_desc;
351         id->offset = 0;
352         for (p = 0; p < iu->number_of_packets - 1; ++p)
353                 id[p + 1].offset = id[p].offset + id[p].length;
354
355         iu->transfer_buffer_length =
356                 id[0].length * iu->number_of_packets;
357 }
358
359 static int submit_urbs(struct usb_stream_kernel *sk,
360                        struct urb *inurb, struct urb *outurb)
361 {
362         int err;
363
364         prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
365         err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
366         if (err < 0)
367                 goto report_failure;
368
369         sk->idle_inurb = sk->completed_inurb;
370         sk->completed_inurb = inurb;
371         err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
372         if (err < 0)
373                 goto report_failure;
374
375         sk->idle_outurb = sk->completed_outurb;
376         sk->completed_outurb = outurb;
377         return 0;
378
379 report_failure:
380         snd_printk(KERN_ERR "%i\n", err);
381         return err;
382 }
383
384 #ifdef DEBUG_LOOP_BACK
385 /*
386   This loop_back() shows how to read/write the period data.
387  */
388 static void loop_back(struct usb_stream *s)
389 {
390         char *i, *o;
391         int il, ol, l, p;
392         struct urb *iu;
393         struct usb_iso_packet_descriptor *id;
394
395         o = s->playback1st_to;
396         ol = s->playback1st_size;
397         l = 0;
398
399         if (s->insplit_pack >= 0) {
400                 iu = sk->idle_inurb;
401                 id = iu->iso_frame_desc;
402                 p = s->insplit_pack;
403         } else
404                 goto second;
405 loop:
406         for (; p < iu->number_of_packets && l < s->period_size; ++p) {
407                 i = iu->transfer_buffer + id[p].offset;
408                 il = id[p].actual_length;
409                 if (l + il > s->period_size)
410                         il = s->period_size - l;
411                 if (il <= ol) {
412                         memcpy(o, i, il);
413                         o += il;
414                         ol -= il;
415                 } else {
416                         memcpy(o, i, ol);
417                         singen_6pack(o, ol);
418                         o = s->playback_to;
419                         memcpy(o, i + ol, il - ol);
420                         o += il - ol;
421                         ol = s->period_size - s->playback1st_size;
422                 }
423                 l += il;
424         }
425         if (iu == sk->completed_inurb) {
426                 if (l != s->period_size)
427                         printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
428                                l/(int)s->cfg.frame_size);
429
430                 return;
431         }
432 second:
433         iu = sk->completed_inurb;
434         id = iu->iso_frame_desc;
435         p = 0;
436         goto loop;
437
438 }
439 #else
440 static void loop_back(struct usb_stream *s)
441 {
442 }
443 #endif
444
445 static void stream_idle(struct usb_stream_kernel *sk,
446                         struct urb *inurb, struct urb *outurb)
447 {
448         struct usb_stream *s = sk->s;
449         int l, p;
450         int insize = s->idle_insize;
451         int urb_size = 0;
452
453         s->inpacket_split = s->next_inpacket_split;
454         s->inpacket_split_at = s->next_inpacket_split_at;
455         s->next_inpacket_split = -1;
456         s->next_inpacket_split_at = 0;
457
458         for (p = 0; p < inurb->number_of_packets; ++p) {
459                 struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
460
461                 l = id[p].actual_length;
462                 if (unlikely(l == 0 || id[p].status)) {
463                         snd_printk(KERN_WARNING "underrun, status=%u\n",
464                                    id[p].status);
465                         goto err_out;
466                 }
467                 s->inpacket_head++;
468                 s->inpacket_head %= s->inpackets;
469                 if (s->inpacket_split == -1)
470                         s->inpacket_split = s->inpacket_head;
471
472                 s->inpacket[s->inpacket_head].offset =
473                         id[p].offset + (inurb->transfer_buffer - (void *)s);
474                 s->inpacket[s->inpacket_head].length = l;
475                 if (insize + l > s->period_size &&
476                     s->next_inpacket_split == -1) {
477                         s->next_inpacket_split = s->inpacket_head;
478                         s->next_inpacket_split_at = s->period_size - insize;
479                 }
480                 insize += l;
481                 urb_size += l;
482         }
483         s->idle_insize += urb_size - s->period_size;
484         if (s->idle_insize < 0) {
485                 snd_printk(KERN_WARNING "%i\n",
486                            (s->idle_insize)/(int)s->cfg.frame_size);
487                 goto err_out;
488         }
489         s->insize_done += urb_size;
490
491         l = s->idle_outsize;
492         s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
493                                   sk->write_page) - l;
494
495         if (usb_stream_prepare_playback(sk, inurb) < 0)
496                 goto err_out;
497
498         s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
499         s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
500                 sk->write_page;
501
502         if (submit_urbs(sk, inurb, outurb) < 0)
503                 goto err_out;
504
505         loop_back(s);
506         s->periods_done++;
507         wake_up_all(&sk->sleep);
508         return;
509 err_out:
510         s->state = usb_stream_xrun;
511         wake_up_all(&sk->sleep);
512 }
513
514 static void i_capture_idle(struct urb *urb)
515 {
516         struct usb_stream_kernel *sk = urb->context;
517
518         if (balance_capture(sk, urb))
519                 stream_idle(sk, urb, sk->i_urb);
520 }
521
522 static void i_playback_idle(struct urb *urb)
523 {
524         struct usb_stream_kernel *sk = urb->context;
525
526         if (balance_playback(sk, urb))
527                 stream_idle(sk, sk->i_urb, urb);
528 }
529
530 static void stream_start(struct usb_stream_kernel *sk,
531                          struct urb *inurb, struct urb *outurb)
532 {
533         struct usb_stream *s = sk->s;
534
535         if (s->state >= usb_stream_sync1) {
536                 int l, p, max_diff, max_diff_0;
537                 int urb_size = 0;
538                 unsigned int frames_per_packet, min_frames = 0;
539
540                 frames_per_packet = (s->period_size - s->idle_insize);
541                 frames_per_packet <<= 8;
542                 frames_per_packet /=
543                         s->cfg.frame_size * inurb->number_of_packets;
544                 frames_per_packet++;
545
546                 max_diff_0 = s->cfg.frame_size;
547                 if (s->cfg.period_frames >= 256)
548                         max_diff_0 <<= 1;
549                 if (s->cfg.period_frames >= 1024)
550                         max_diff_0 <<= 1;
551                 max_diff = max_diff_0;
552                 for (p = 0; p < inurb->number_of_packets; ++p) {
553                         int diff;
554
555                         l = inurb->iso_frame_desc[p].actual_length;
556                         urb_size += l;
557
558                         min_frames += frames_per_packet;
559                         diff = urb_size -
560                                 (min_frames >> 8) * s->cfg.frame_size;
561                         if (diff < max_diff) {
562                                 snd_printdd(KERN_DEBUG "%i %i %i %i\n",
563                                             s->insize_done,
564                                             urb_size / (int)s->cfg.frame_size,
565                                             inurb->number_of_packets, diff);
566                                 max_diff = diff;
567                         }
568                 }
569                 s->idle_insize -= max_diff - max_diff_0;
570                 s->idle_insize += urb_size - s->period_size;
571                 if (s->idle_insize < 0) {
572                         snd_printk(KERN_WARNING "%i %i %i\n",
573                                    s->idle_insize, urb_size, s->period_size);
574                         return;
575                 } else if (s->idle_insize == 0) {
576                         s->next_inpacket_split =
577                                 (s->inpacket_head + 1) % s->inpackets;
578                         s->next_inpacket_split_at = 0;
579                 } else {
580                         unsigned int split = s->inpacket_head;
581
582                         l = s->idle_insize;
583                         while (l > s->inpacket[split].length) {
584                                 l -= s->inpacket[split].length;
585                                 if (split == 0)
586                                         split = s->inpackets - 1;
587                                 else
588                                         split--;
589                         }
590                         s->next_inpacket_split = split;
591                         s->next_inpacket_split_at =
592                                 s->inpacket[split].length - l;
593                 }
594
595                 s->insize_done += urb_size;
596
597                 if (usb_stream_prepare_playback(sk, inurb) < 0)
598                         return;
599
600         } else
601                 playback_prep_freqn(sk, sk->idle_outurb);
602
603         if (submit_urbs(sk, inurb, outurb) < 0)
604                 return;
605
606         if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
607                 /* just guesswork                            ^^^^^^ */
608                 s->state = usb_stream_ready;
609                 subs_set_complete(sk->inurb, i_capture_idle);
610                 subs_set_complete(sk->outurb, i_playback_idle);
611         }
612 }
613
614 static void i_capture_start(struct urb *urb)
615 {
616         struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
617         struct usb_stream_kernel *sk = urb->context;
618         struct usb_stream *s = sk->s;
619         int p;
620         int empty = 0;
621
622         if (urb->status) {
623                 snd_printk(KERN_WARNING "status=%i\n", urb->status);
624                 return;
625         }
626
627         for (p = 0; p < urb->number_of_packets; ++p) {
628                 int l = id[p].actual_length;
629
630                 if (l < s->cfg.frame_size) {
631                         ++empty;
632                         if (s->state >= usb_stream_sync0) {
633                                 snd_printk(KERN_WARNING "%i\n", l);
634                                 return;
635                         }
636                 }
637                 s->inpacket_head++;
638                 s->inpacket_head %= s->inpackets;
639                 s->inpacket[s->inpacket_head].offset =
640                         id[p].offset + (urb->transfer_buffer - (void *)s);
641                 s->inpacket[s->inpacket_head].length = l;
642         }
643 #ifdef SHOW_EMPTY
644         if (empty) {
645                 printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
646                        urb->iso_frame_desc[0].actual_length);
647                 for (pack = 1; pack < urb->number_of_packets; ++pack) {
648                         int l = urb->iso_frame_desc[pack].actual_length;
649
650                         printk(KERN_CONT " %i", l);
651                 }
652                 printk(KERN_CONT "\n");
653         }
654 #endif
655         if (!empty && s->state < usb_stream_sync1)
656                 ++s->state;
657
658         if (balance_capture(sk, urb))
659                 stream_start(sk, urb, sk->i_urb);
660 }
661
662 static void i_playback_start(struct urb *urb)
663 {
664         struct usb_stream_kernel *sk = urb->context;
665
666         if (balance_playback(sk, urb))
667                 stream_start(sk, sk->i_urb, urb);
668 }
669
670 int usb_stream_start(struct usb_stream_kernel *sk)
671 {
672         struct usb_stream *s = sk->s;
673         int frame = 0, iters = 0;
674         int u, err;
675         int try = 0;
676
677         if (s->state != usb_stream_stopped)
678                 return -EAGAIN;
679
680         subs_set_complete(sk->inurb, i_capture_start);
681         subs_set_complete(sk->outurb, i_playback_start);
682         memset(sk->write_page, 0, s->write_size);
683 dotry:
684         s->insize_done = 0;
685         s->idle_insize = 0;
686         s->idle_outsize = 0;
687         s->sync_packet = -1;
688         s->inpacket_head = -1;
689         sk->iso_frame_balance = 0;
690         ++try;
691         for (u = 0; u < 2; u++) {
692                 struct urb *inurb = sk->inurb[u];
693                 struct urb *outurb = sk->outurb[u];
694
695                 playback_prep_freqn(sk, outurb);
696                 inurb->number_of_packets = outurb->number_of_packets;
697                 inurb->transfer_buffer_length =
698                         inurb->number_of_packets *
699                         inurb->iso_frame_desc[0].length;
700
701                 if (u == 0) {
702                         int now;
703                         struct usb_device *dev = inurb->dev;
704
705                         frame = usb_get_current_frame_number(dev);
706                         do {
707                                 now = usb_get_current_frame_number(dev);
708                                 ++iters;
709                         } while (now > -1 && now == frame);
710                 }
711                 err = usb_submit_urb(inurb, GFP_ATOMIC);
712                 if (err < 0) {
713                         snd_printk(KERN_ERR
714                                    "usb_submit_urb(sk->inurb[%i]) returned %i\n",
715                                    u, err);
716                         return err;
717                 }
718                 err = usb_submit_urb(outurb, GFP_ATOMIC);
719                 if (err < 0) {
720                         snd_printk(KERN_ERR
721                                    "usb_submit_urb(sk->outurb[%i]) returned %i\n",
722                                    u, err);
723                         return err;
724                 }
725
726                 if (inurb->start_frame != outurb->start_frame) {
727                         snd_printd(KERN_DEBUG
728                                    "u[%i] start_frames differ in:%u out:%u\n",
729                                    u, inurb->start_frame, outurb->start_frame);
730                         goto check_retry;
731                 }
732         }
733         snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
734         try = 0;
735 check_retry:
736         if (try) {
737                 usb_stream_stop(sk);
738                 if (try < 5) {
739                         msleep(1500);
740                         snd_printd(KERN_DEBUG "goto dotry;\n");
741                         goto dotry;
742                 }
743                 snd_printk(KERN_WARNING
744                            "couldn't start all urbs on the same start_frame.\n");
745                 return -EFAULT;
746         }
747
748         sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
749         sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
750         sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
751         sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
752
753 /* wait, check */
754         {
755                 int wait_ms = 3000;
756
757                 while (s->state != usb_stream_ready && wait_ms > 0) {
758                         snd_printdd(KERN_DEBUG "%i\n", s->state);
759                         msleep(200);
760                         wait_ms -= 200;
761                 }
762         }
763
764         return s->state == usb_stream_ready ? 0 : -EFAULT;
765 }
766
767
768 /*                             stop                                   */
769
770 void usb_stream_stop(struct usb_stream_kernel *sk)
771 {
772         int u;
773
774         if (!sk->s)
775                 return;
776         for (u = 0; u < USB_STREAM_NURBS; ++u) {
777                 usb_kill_urb(sk->inurb[u]);
778                 usb_kill_urb(sk->outurb[u]);
779         }
780         sk->s->state = usb_stream_stopped;
781         msleep(400);
782 }