1e7a47a86605078d2934720f168da85cbf8145ce
[pandora-kernel.git] / sound / usb / usx2y / usb_stream.c
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_flags = URB_ISO_ASAP;
73                 urb->transfer_buffer = transfer;
74                 urb->dev = dev;
75                 urb->pipe = pipe;
76                 urb->number_of_packets = sk->n_o_ps;
77                 urb->context = sk;
78                 urb->interval = 1;
79                 if (usb_pipeout(pipe))
80                         continue;
81
82                 urb->transfer_buffer_length = transfer_length;
83                 desc = urb->iso_frame_desc;
84                 desc->offset = 0;
85                 desc->length = maxpacket;
86                 for (p = 1; p < sk->n_o_ps; ++p) {
87                         desc[p].offset = desc[p - 1].offset + maxpacket;
88                         desc[p].length = maxpacket;
89                 }
90         }
91 }
92
93 static void init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
94                       struct usb_device *dev, int in_pipe, int out_pipe)
95 {
96         struct usb_stream       *s = sk->s;
97         char                    *indata = (char *)s + sizeof(*s) +
98                                         sizeof(struct usb_stream_packet) *
99                                         s->inpackets;
100         int                     u;
101
102         for (u = 0; u < USB_STREAM_NURBS; ++u) {
103                 sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
104                 sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
105         }
106
107         init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe);
108         init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
109                        out_pipe);
110 }
111
112
113 /*
114  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
115  * this will overflow at approx 524 kHz
116  */
117 static inline unsigned get_usb_full_speed_rate(unsigned rate)
118 {
119         return ((rate << 13) + 62) / 125;
120 }
121
122 /*
123  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
124  * this will overflow at approx 4 MHz
125  */
126 static inline unsigned get_usb_high_speed_rate(unsigned rate)
127 {
128         return ((rate << 10) + 62) / 125;
129 }
130
131 void usb_stream_free(struct usb_stream_kernel *sk)
132 {
133         struct usb_stream *s;
134         unsigned u;
135
136         for (u = 0; u < USB_STREAM_NURBS; ++u) {
137                 usb_free_urb(sk->inurb[u]);
138                 sk->inurb[u] = NULL;
139                 usb_free_urb(sk->outurb[u]);
140                 sk->outurb[u] = NULL;
141         }
142
143         s = sk->s;
144         if (!s)
145                 return;
146
147         free_pages((unsigned long)sk->write_page, get_order(s->write_size));
148         sk->write_page = NULL;
149         free_pages((unsigned long)s, get_order(s->read_size));
150         sk->s = NULL;
151 }
152
153 struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
154                                   struct usb_device *dev,
155                                   unsigned in_endpoint, unsigned out_endpoint,
156                                   unsigned sample_rate, unsigned use_packsize,
157                                   unsigned period_frames, unsigned frame_size)
158 {
159         int packets, max_packsize;
160         int in_pipe, out_pipe;
161         int read_size = sizeof(struct usb_stream);
162         int write_size;
163         int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
164         int pg;
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         pg = get_order(read_size);
195         sk->s = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO, 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, pg);
216         if (!sk->write_page) {
217                 snd_printk(KERN_WARNING "couldn't __get_free_pages()\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         init_urbs(sk, use_packsize, dev, in_pipe, out_pipe);
229         sk->s->state = usb_stream_stopped;
230 out:
231         return sk->s;
232 }
233
234
235 /*                             start                                  */
236
237 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
238 {
239         bool r;
240         if (unlikely(urb->status)) {
241                 if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
242                         snd_printk(KERN_WARNING "status=%i\n", urb->status);
243                 sk->iso_frame_balance = 0x7FFFFFFF;
244                 return false;
245         }
246         r = sk->iso_frame_balance == 0;
247         if (!r)
248                 sk->i_urb = urb;
249         return r;
250 }
251
252 static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
253 {
254         sk->iso_frame_balance += urb->number_of_packets;
255         return balance_check(sk, urb);
256 }
257
258 static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
259 {
260         sk->iso_frame_balance -= urb->number_of_packets;
261         return balance_check(sk, urb);
262 }
263
264 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
265 {
266         int u;
267
268         for (u = 0; u < USB_STREAM_NURBS; u++) {
269                 struct urb *urb = urbs[u];
270                 urb->complete = complete;
271         }
272 }
273
274 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
275                 struct urb *inurb)
276 {
277         struct usb_stream *s = sk->s;
278         struct urb *io;
279         struct usb_iso_packet_descriptor *id, *od;
280         int p = 0, lb = 0, l = 0;
281
282         io = sk->idle_outurb;
283         od = io->iso_frame_desc;
284
285         for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
286                 struct urb *ii = sk->completed_inurb;
287                 id = ii->iso_frame_desc +
288                         ii->number_of_packets + s->sync_packet;
289                 l = id->actual_length;
290
291                 od[p].length = l;
292                 od[p].offset = lb;
293                 lb += l;
294         }
295
296         for (;
297              s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
298              ++p, ++s->sync_packet) {
299                 l = inurb->iso_frame_desc[s->sync_packet].actual_length;
300
301                 if (s->idle_outsize + lb + l > s->period_size)
302                         goto check_ok;
303
304                 od[p].length = l;
305                 od[p].offset = lb;
306                 lb += l;
307         }
308
309 check_ok:
310         s->sync_packet -= inurb->number_of_packets;
311         if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
312                 snd_printk(KERN_WARNING "invalid sync_packet = %i;"
313                            " p=%i nop=%i %i %x %x %x > %x\n",
314                            s->sync_packet, p, inurb->number_of_packets,
315                            s->idle_outsize + lb + l,
316                            s->idle_outsize, lb,  l,
317                            s->period_size);
318                 return -1;
319         }
320         if (unlikely(lb % s->cfg.frame_size)) {
321                 snd_printk(KERN_WARNING"invalid outsize = %i\n",
322                            lb);
323                 return -1;
324         }
325         s->idle_outsize += lb - s->period_size;
326         io->number_of_packets = p;
327         io->transfer_buffer_length = lb;
328         if (s->idle_outsize <= 0)
329                 return 0;
330
331         snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
332         return -1;
333 }
334
335 static void prepare_inurb(int number_of_packets, struct urb *iu)
336 {
337         struct usb_iso_packet_descriptor *id;
338         int p;
339
340         iu->number_of_packets = number_of_packets;
341         id = iu->iso_frame_desc;
342         id->offset = 0;
343         for (p = 0; p < iu->number_of_packets - 1; ++p)
344                 id[p + 1].offset = id[p].offset + id[p].length;
345
346         iu->transfer_buffer_length =
347                 id[0].length * iu->number_of_packets;
348 }
349
350 static int submit_urbs(struct usb_stream_kernel *sk,
351                        struct urb *inurb, struct urb *outurb)
352 {
353         int err;
354         prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
355         err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
356         if (err < 0) {
357                 snd_printk(KERN_ERR "%i\n", err);
358                 return err;
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                 snd_printk(KERN_ERR "%i\n", err);
365                 return err;
366         }
367         sk->idle_outurb = sk->completed_outurb;
368         sk->completed_outurb = outurb;
369         return 0;
370 }
371
372 #ifdef DEBUG_LOOP_BACK
373 /*
374   This loop_back() shows how to read/write the period data.
375  */
376 static void loop_back(struct usb_stream *s)
377 {
378         char *i, *o;
379         int il, ol, l, p;
380         struct urb *iu;
381         struct usb_iso_packet_descriptor *id;
382
383         o = s->playback1st_to;
384         ol = s->playback1st_size;
385         l = 0;
386
387         if (s->insplit_pack >= 0) {
388                 iu = sk->idle_inurb;
389                 id = iu->iso_frame_desc;
390                 p = s->insplit_pack;
391         } else
392                 goto second;
393 loop:
394         for (; p < iu->number_of_packets && l < s->period_size; ++p) {
395                 i = iu->transfer_buffer + id[p].offset;
396                 il = id[p].actual_length;
397                 if (l + il > s->period_size)
398                         il = s->period_size - l;
399                 if (il <= ol) {
400                         memcpy(o, i, il);
401                         o += il;
402                         ol -= il;
403                 } else {
404                         memcpy(o, i, ol);
405                         singen_6pack(o, ol);
406                         o = s->playback_to;
407                         memcpy(o, i + ol, il - ol);
408                         o += il - ol;
409                         ol = s->period_size - s->playback1st_size;
410                 }
411                 l += il;
412         }
413         if (iu == sk->completed_inurb) {
414                 if (l != s->period_size)
415                         printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
416                                l/(int)s->cfg.frame_size);
417
418                 return;
419         }
420 second:
421         iu = sk->completed_inurb;
422         id = iu->iso_frame_desc;
423         p = 0;
424         goto loop;
425
426 }
427 #else
428 static void loop_back(struct usb_stream *s)
429 {
430 }
431 #endif
432
433 static void stream_idle(struct usb_stream_kernel *sk,
434                         struct urb *inurb, struct urb *outurb)
435 {
436         struct usb_stream *s = sk->s;
437         int l, p;
438         int insize = s->idle_insize;
439         int urb_size = 0;
440
441         s->inpacket_split = s->next_inpacket_split;
442         s->inpacket_split_at = s->next_inpacket_split_at;
443         s->next_inpacket_split = -1;
444         s->next_inpacket_split_at = 0;
445
446         for (p = 0; p < inurb->number_of_packets; ++p) {
447                 struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
448                 l = id[p].actual_length;
449                 if (unlikely(l == 0 || id[p].status)) {
450                         snd_printk(KERN_WARNING "underrun, status=%u\n",
451                                    id[p].status);
452                         goto err_out;
453                 }
454                 s->inpacket_head++;
455                 s->inpacket_head %= s->inpackets;
456                 if (s->inpacket_split == -1)
457                         s->inpacket_split = s->inpacket_head;
458
459                 s->inpacket[s->inpacket_head].offset =
460                         id[p].offset + (inurb->transfer_buffer - (void *)s);
461                 s->inpacket[s->inpacket_head].length = l;
462                 if (insize + l > s->period_size &&
463                     s->next_inpacket_split == -1) {
464                         s->next_inpacket_split = s->inpacket_head;
465                         s->next_inpacket_split_at = s->period_size - insize;
466                 }
467                 insize += l;
468                 urb_size += l;
469         }
470         s->idle_insize += urb_size - s->period_size;
471         if (s->idle_insize < 0) {
472                 snd_printk(KERN_WARNING "%i\n",
473                            (s->idle_insize)/(int)s->cfg.frame_size);
474                 goto err_out;
475         }
476         s->insize_done += urb_size;
477
478         l = s->idle_outsize;
479         s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
480                                   sk->write_page) - l;
481
482         if (usb_stream_prepare_playback(sk, inurb) < 0)
483                 goto err_out;
484
485         s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
486         s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
487                 sk->write_page;
488
489         if (submit_urbs(sk, inurb, outurb) < 0)
490                 goto err_out;
491
492         loop_back(s);
493         s->periods_done++;
494         wake_up_all(&sk->sleep);
495         return;
496 err_out:
497         s->state = usb_stream_xrun;
498         wake_up_all(&sk->sleep);
499 }
500
501 static void i_capture_idle(struct urb *urb)
502 {
503         struct usb_stream_kernel *sk = urb->context;
504         if (balance_capture(sk, urb))
505                 stream_idle(sk, urb, sk->i_urb);
506 }
507
508 static void i_playback_idle(struct urb *urb)
509 {
510         struct usb_stream_kernel *sk = urb->context;
511         if (balance_playback(sk, urb))
512                 stream_idle(sk, sk->i_urb, urb);
513 }
514
515 static void stream_start(struct usb_stream_kernel *sk,
516                          struct urb *inurb, struct urb *outurb)
517 {
518         struct usb_stream *s = sk->s;
519         if (s->state >= usb_stream_sync1) {
520                 int l, p, max_diff, max_diff_0;
521                 int urb_size = 0;
522                 unsigned frames_per_packet, min_frames = 0;
523                 frames_per_packet = (s->period_size - s->idle_insize);
524                 frames_per_packet <<= 8;
525                 frames_per_packet /=
526                         s->cfg.frame_size * inurb->number_of_packets;
527                 frames_per_packet++;
528
529                 max_diff_0 = s->cfg.frame_size;
530                 if (s->cfg.period_frames >= 256)
531                         max_diff_0 <<= 1;
532                 if (s->cfg.period_frames >= 1024)
533                         max_diff_0 <<= 1;
534                 max_diff = max_diff_0;
535                 for (p = 0; p < inurb->number_of_packets; ++p) {
536                         int diff;
537                         l = inurb->iso_frame_desc[p].actual_length;
538                         urb_size += l;
539
540                         min_frames += frames_per_packet;
541                         diff = urb_size -
542                                 (min_frames >> 8) * s->cfg.frame_size;
543                         if (diff < max_diff) {
544                                 snd_printdd(KERN_DEBUG "%i %i %i %i\n",
545                                             s->insize_done,
546                                             urb_size / (int)s->cfg.frame_size,
547                                             inurb->number_of_packets, diff);
548                                 max_diff = diff;
549                         }
550                 }
551                 s->idle_insize -= max_diff - max_diff_0;
552                 s->idle_insize += urb_size - s->period_size;
553                 if (s->idle_insize < 0) {
554                         snd_printk(KERN_WARNING "%i %i %i\n",
555                                    s->idle_insize, urb_size, s->period_size);
556                         return;
557                 } else if (s->idle_insize == 0) {
558                         s->next_inpacket_split =
559                                 (s->inpacket_head + 1) % s->inpackets;
560                         s->next_inpacket_split_at = 0;
561                 } else {
562                         unsigned split = s->inpacket_head;
563                         l = s->idle_insize;
564                         while (l > s->inpacket[split].length) {
565                                 l -= s->inpacket[split].length;
566                                 if (split == 0)
567                                         split = s->inpackets - 1;
568                                 else
569                                         split--;
570                         }
571                         s->next_inpacket_split = split;
572                         s->next_inpacket_split_at =
573                                 s->inpacket[split].length - l;
574                 }
575
576                 s->insize_done += urb_size;
577
578                 if (usb_stream_prepare_playback(sk, inurb) < 0)
579                         return;
580
581         } else
582                 playback_prep_freqn(sk, sk->idle_outurb);
583
584         if (submit_urbs(sk, inurb, outurb) < 0)
585                 return;
586
587         if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
588                 /* just guesswork                            ^^^^^^ */
589                 s->state = usb_stream_ready;
590                 subs_set_complete(sk->inurb, i_capture_idle);
591                 subs_set_complete(sk->outurb, i_playback_idle);
592         }
593 }
594
595 static void i_capture_start(struct urb *urb)
596 {
597         struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
598         struct usb_stream_kernel *sk = urb->context;
599         struct usb_stream *s = sk->s;
600         int p;
601         int empty = 0;
602
603         if (urb->status) {
604                 snd_printk(KERN_WARNING "status=%i\n", urb->status);
605                 return;
606         }
607
608         for (p = 0; p < urb->number_of_packets; ++p) {
609                 int l = id[p].actual_length;
610                 if (l < s->cfg.frame_size) {
611                         ++empty;
612                         if (s->state >= usb_stream_sync0) {
613                                 snd_printk(KERN_WARNING "%i\n", l);
614                                 return;
615                         }
616                 }
617                 s->inpacket_head++;
618                 s->inpacket_head %= s->inpackets;
619                 s->inpacket[s->inpacket_head].offset =
620                         id[p].offset + (urb->transfer_buffer - (void *)s);
621                 s->inpacket[s->inpacket_head].length = l;
622         }
623 #ifdef SHOW_EMPTY
624         if (empty) {
625                 printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
626                        urb->iso_frame_desc[0].actual_length);
627                 for (pack = 1; pack < urb->number_of_packets; ++pack) {
628                         int l = urb->iso_frame_desc[pack].actual_length;
629                         printk(" %i", l);
630                 }
631                 printk("\n");
632         }
633 #endif
634         if (!empty && s->state < usb_stream_sync1)
635                 ++s->state;
636
637         if (balance_capture(sk, urb))
638                 stream_start(sk, urb, sk->i_urb);
639 }
640
641 static void i_playback_start(struct urb *urb)
642 {
643         struct usb_stream_kernel *sk = urb->context;
644         if (balance_playback(sk, urb))
645                 stream_start(sk, sk->i_urb, urb);
646 }
647
648 int usb_stream_start(struct usb_stream_kernel *sk)
649 {
650         struct usb_stream *s = sk->s;
651         int frame = 0, iters = 0;
652         int u, err;
653         int try = 0;
654
655         if (s->state != usb_stream_stopped)
656                 return -EAGAIN;
657
658         subs_set_complete(sk->inurb, i_capture_start);
659         subs_set_complete(sk->outurb, i_playback_start);
660         memset(sk->write_page, 0, s->write_size);
661 dotry:
662         s->insize_done = 0;
663         s->idle_insize = 0;
664         s->idle_outsize = 0;
665         s->sync_packet = -1;
666         s->inpacket_head = -1;
667         sk->iso_frame_balance = 0;
668         ++try;
669         for (u = 0; u < 2; u++) {
670                 struct urb *inurb = sk->inurb[u];
671                 struct urb *outurb = sk->outurb[u];
672                 playback_prep_freqn(sk, outurb);
673                 inurb->number_of_packets = outurb->number_of_packets;
674                 inurb->transfer_buffer_length =
675                         inurb->number_of_packets *
676                         inurb->iso_frame_desc[0].length;
677
678                 if (u == 0) {
679                         int now;
680                         struct usb_device *dev = inurb->dev;
681                         frame = usb_get_current_frame_number(dev);
682                         do {
683                                 now = usb_get_current_frame_number(dev);
684                                 ++iters;
685                         } while (now > -1 && now == frame);
686                 }
687                 err = usb_submit_urb(inurb, GFP_ATOMIC);
688                 if (err < 0) {
689                         snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
690                                    " returned %i\n", u, err);
691                         return err;
692                 }
693                 err = usb_submit_urb(outurb, GFP_ATOMIC);
694                 if (err < 0) {
695                         snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
696                                    " returned %i\n", u, err);
697                         return err;
698                 }
699
700                 if (inurb->start_frame != outurb->start_frame) {
701                         snd_printd(KERN_DEBUG
702                                    "u[%i] start_frames differ in:%u out:%u\n",
703                                    u, inurb->start_frame, outurb->start_frame);
704                         goto check_retry;
705                 }
706         }
707         snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
708         try = 0;
709 check_retry:
710         if (try) {
711                 usb_stream_stop(sk);
712                 if (try < 5) {
713                         msleep(1500);
714                         snd_printd(KERN_DEBUG "goto dotry;\n");
715                         goto dotry;
716                 }
717                 snd_printk(KERN_WARNING"couldn't start"
718                            " all urbs on the same start_frame.\n");
719                 return -EFAULT;
720         }
721
722         sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
723         sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
724         sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
725         sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
726
727 /* wait, check */
728         {
729                 int wait_ms = 3000;
730                 while (s->state != usb_stream_ready && wait_ms > 0) {
731                         snd_printdd(KERN_DEBUG "%i\n", s->state);
732                         msleep(200);
733                         wait_ms -= 200;
734                 }
735         }
736
737         return s->state == usb_stream_ready ? 0 : -EFAULT;
738 }
739
740
741 /*                             stop                                   */
742
743 void usb_stream_stop(struct usb_stream_kernel *sk)
744 {
745         int u;
746         if (!sk->s)
747                 return;
748         for (u = 0; u < USB_STREAM_NURBS; ++u) {
749                 usb_kill_urb(sk->inurb[u]);
750                 usb_kill_urb(sk->outurb[u]);
751         }
752         sk->s->state = usb_stream_stopped;
753         msleep(400);
754 }