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_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                 snd_printk(KERN_ERR "%i\n", err);
 359                 return err;
 360         }
 361         sk->idle_inurb = sk->completed_inurb;
 362         sk->completed_inurb = inurb;
 363         err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
 364         if (err < 0) {
 365                 snd_printk(KERN_ERR "%i\n", err);
 366                 return err;
 367         }
 368         sk->idle_outurb = sk->completed_outurb;
 369         sk->completed_outurb = outurb;
 370         return 0;
 371 }
 372
 373 #ifdef DEBUG_LOOP_BACK
 374 /*
 375   This loop_back() shows how to read/write the period data.
 376  */
 377 static void loop_back(struct usb_stream *s)
 378 {
 379         char *i, *o;
 380         int il, ol, l, p;
 381         struct urb *iu;
 382         struct usb_iso_packet_descriptor *id;
 383
 384         o = s->playback1st_to;
 385         ol = s->playback1st_size;
 386         l = 0;
 387
 388         if (s->insplit_pack >= 0) {
 389                 iu = sk->idle_inurb;
 390                 id = iu->iso_frame_desc;
 391                 p = s->insplit_pack;
 392         } else
 393                 goto second;
 394 loop:
 395         for (; p < iu->number_of_packets && l < s->period_size; ++p) {
 396                 i = iu->transfer_buffer + id[p].offset;
 397                 il = id[p].actual_length;
 398                 if (l + il > s->period_size)
 399                         il = s->period_size - l;
 400                 if (il <= ol) {
 401                         memcpy(o, i, il);
 402                         o += il;
 403                         ol -= il;
 404                 } else {
 405                         memcpy(o, i, ol);
 406                         singen_6pack(o, ol);
 407                         o = s->playback_to;
 408                         memcpy(o, i + ol, il - ol);
 409                         o += il - ol;
 410                         ol = s->period_size - s->playback1st_size;
 411                 }
 412                 l += il;
 413         }
 414         if (iu == sk->completed_inurb) {
 415                 if (l != s->period_size)
 416                         printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
 417                                l/(int)s->cfg.frame_size);
 418
 419                 return;
 420         }
 421 second:
 422         iu = sk->completed_inurb;
 423         id = iu->iso_frame_desc;
 424         p = 0;
 425         goto loop;
 426
 427 }
 428 #else
 429 static void loop_back(struct usb_stream *s)
 430 {
 431 }
 432 #endif
 433
 434 static void stream_idle(struct usb_stream_kernel *sk,
 435                         struct urb *inurb, struct urb *outurb)
 436 {
 437         struct usb_stream *s = sk->s;
 438         int l, p;
 439         int insize = s->idle_insize;
 440         int urb_size = 0;
 441
 442         s->inpacket_split = s->next_inpacket_split;
 443         s->inpacket_split_at = s->next_inpacket_split_at;
 444         s->next_inpacket_split = -1;
 445         s->next_inpacket_split_at = 0;
 446
 447         for (p = 0; p < inurb->number_of_packets; ++p) {
 448                 struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
 449                 l = id[p].actual_length;
 450                 if (unlikely(l == 0 || id[p].status)) {
 451                         snd_printk(KERN_WARNING "underrun, status=%u\n",
 452                                    id[p].status);
 453                         goto err_out;
 454                 }
 455                 s->inpacket_head++;
 456                 s->inpacket_head %= s->inpackets;
 457                 if (s->inpacket_split == -1)
 458                         s->inpacket_split = s->inpacket_head;
 459
 460                 s->inpacket[s->inpacket_head].offset =
 461                         id[p].offset + (inurb->transfer_buffer - (void *)s);
 462                 s->inpacket[s->inpacket_head].length = l;
 463                 if (insize + l > s->period_size &&
 464                     s->next_inpacket_split == -1) {
 465                         s->next_inpacket_split = s->inpacket_head;
 466                         s->next_inpacket_split_at = s->period_size - insize;
 467                 }
 468                 insize += l;
 469                 urb_size += l;
 470         }
 471         s->idle_insize += urb_size - s->period_size;
 472         if (s->idle_insize < 0) {
 473                 snd_printk(KERN_WARNING "%i\n",
 474                            (s->idle_insize)/(int)s->cfg.frame_size);
 475                 goto err_out;
 476         }
 477         s->insize_done += urb_size;
 478
 479         l = s->idle_outsize;
 480         s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
 481                                   sk->write_page) - l;
 482
 483         if (usb_stream_prepare_playback(sk, inurb) < 0)
 484                 goto err_out;
 485
 486         s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
 487         s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
 488                 sk->write_page;
 489
 490         if (submit_urbs(sk, inurb, outurb) < 0)
 491                 goto err_out;
 492
 493         loop_back(s);
 494         s->periods_done++;
 495         wake_up_all(&sk->sleep);
 496         return;
 497 err_out:
 498         s->state = usb_stream_xrun;
 499         wake_up_all(&sk->sleep);
 500 }
 501
 502 static void i_capture_idle(struct urb *urb)
 503 {
 504         struct usb_stream_kernel *sk = urb->context;
 505         if (balance_capture(sk, urb))
 506                 stream_idle(sk, urb, sk->i_urb);
 507 }
 508
 509 static void i_playback_idle(struct urb *urb)
 510 {
 511         struct usb_stream_kernel *sk = urb->context;
 512         if (balance_playback(sk, urb))
 513                 stream_idle(sk, sk->i_urb, urb);
 514 }
 515
 516 static void stream_start(struct usb_stream_kernel *sk,
 517                          struct urb *inurb, struct urb *outurb)
 518 {
 519         struct usb_stream *s = sk->s;
 520         if (s->state >= usb_stream_sync1) {
 521                 int l, p, max_diff, max_diff_0;
 522                 int urb_size = 0;
 523                 unsigned frames_per_packet, min_frames = 0;
 524                 frames_per_packet = (s->period_size - s->idle_insize);
 525                 frames_per_packet <<= 8;
 526                 frames_per_packet /=
 527                         s->cfg.frame_size * inurb->number_of_packets;
 528                 frames_per_packet++;
 529
 530                 max_diff_0 = s->cfg.frame_size;
 531                 if (s->cfg.period_frames >= 256)
 532                         max_diff_0 <<= 1;
 533                 if (s->cfg.period_frames >= 1024)
 534                         max_diff_0 <<= 1;
 535                 max_diff = max_diff_0;
 536                 for (p = 0; p < inurb->number_of_packets; ++p) {
 537                         int diff;
 538                         l = inurb->iso_frame_desc[p].actual_length;
 539                         urb_size += l;
 540
 541                         min_frames += frames_per_packet;
 542                         diff = urb_size -
 543                                 (min_frames >> 8) * s->cfg.frame_size;
 544                         if (diff < max_diff) {
 545                                 snd_printdd(KERN_DEBUG "%i %i %i %i\n",
 546                                             s->insize_done,
 547                                             urb_size / (int)s->cfg.frame_size,
 548                                             inurb->number_of_packets, diff);
 549                                 max_diff = diff;
 550                         }
 551                 }
 552                 s->idle_insize -= max_diff - max_diff_0;
 553                 s->idle_insize += urb_size - s->period_size;
 554                 if (s->idle_insize < 0) {
 555                         snd_printk(KERN_WARNING "%i %i %i\n",
 556                                    s->idle_insize, urb_size, s->period_size);
 557                         return;
 558                 } else if (s->idle_insize == 0) {
 559                         s->next_inpacket_split =
 560                                 (s->inpacket_head + 1) % s->inpackets;
 561                         s->next_inpacket_split_at = 0;
 562                 } else {
 563                         unsigned split = s->inpacket_head;
 564                         l = s->idle_insize;
 565                         while (l > s->inpacket[split].length) {
 566                                 l -= s->inpacket[split].length;
 567                                 if (split == 0)
 568                                         split = s->inpackets - 1;
 569                                 else
 570                                         split--;
 571                         }
 572                         s->next_inpacket_split = split;
 573                         s->next_inpacket_split_at =
 574                                 s->inpacket[split].length - l;
 575                 }
 576
 577                 s->insize_done += urb_size;
 578
 579                 if (usb_stream_prepare_playback(sk, inurb) < 0)
 580                         return;
 581
 582         } else
 583                 playback_prep_freqn(sk, sk->idle_outurb);
 584
 585         if (submit_urbs(sk, inurb, outurb) < 0)
 586                 return;
 587
 588         if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
 589                 /* just guesswork                            ^^^^^^ */
 590                 s->state = usb_stream_ready;
 591                 subs_set_complete(sk->inurb, i_capture_idle);
 592                 subs_set_complete(sk->outurb, i_playback_idle);
 593         }
 594 }
 595
 596 static void i_capture_start(struct urb *urb)
 597 {
 598         struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
 599         struct usb_stream_kernel *sk = urb->context;
 600         struct usb_stream *s = sk->s;
 601         int p;
 602         int empty = 0;
 603
 604         if (urb->status) {
 605                 snd_printk(KERN_WARNING "status=%i\n", urb->status);
 606                 return;
 607         }
 608
 609         for (p = 0; p < urb->number_of_packets; ++p) {
 610                 int l = id[p].actual_length;
 611                 if (l < s->cfg.frame_size) {
 612                         ++empty;
 613                         if (s->state >= usb_stream_sync0) {
 614                                 snd_printk(KERN_WARNING "%i\n", l);
 615                                 return;
 616                         }
 617                 }
 618                 s->inpacket_head++;
 619                 s->inpacket_head %= s->inpackets;
 620                 s->inpacket[s->inpacket_head].offset =
 621                         id[p].offset + (urb->transfer_buffer - (void *)s);
 622                 s->inpacket[s->inpacket_head].length = l;
 623         }
 624 #ifdef SHOW_EMPTY
 625         if (empty) {
 626                 printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
 627                        urb->iso_frame_desc[0].actual_length);
 628                 for (pack = 1; pack < urb->number_of_packets; ++pack) {
 629                         int l = urb->iso_frame_desc[pack].actual_length;
 630                         printk(" %i", l);
 631                 }
 632                 printk("\n");
 633         }
 634 #endif
 635         if (!empty && s->state < usb_stream_sync1)
 636                 ++s->state;
 637
 638         if (balance_capture(sk, urb))
 639                 stream_start(sk, urb, sk->i_urb);
 640 }
 641
 642 static void i_playback_start(struct urb *urb)
 643 {
 644         struct usb_stream_kernel *sk = urb->context;
 645         if (balance_playback(sk, urb))
 646                 stream_start(sk, sk->i_urb, urb);
 647 }
 648
 649 int usb_stream_start(struct usb_stream_kernel *sk)
 650 {
 651         struct usb_stream *s = sk->s;
 652         int frame = 0, iters = 0;
 653         int u, err;
 654         int try = 0;
 655
 656         if (s->state != usb_stream_stopped)
 657                 return -EAGAIN;
 658
 659         subs_set_complete(sk->inurb, i_capture_start);
 660         subs_set_complete(sk->outurb, i_playback_start);
 661         memset(sk->write_page, 0, s->write_size);
 662 dotry:
 663         s->insize_done = 0;
 664         s->idle_insize = 0;
 665         s->idle_outsize = 0;
 666         s->sync_packet = -1;
 667         s->inpacket_head = -1;
 668         sk->iso_frame_balance = 0;
 669         ++try;
 670         for (u = 0; u < 2; u++) {
 671                 struct urb *inurb = sk->inurb[u];
 672                 struct urb *outurb = sk->outurb[u];
 673                 playback_prep_freqn(sk, outurb);
 674                 inurb->number_of_packets = outurb->number_of_packets;
 675                 inurb->transfer_buffer_length =
 676                         inurb->number_of_packets *
 677                         inurb->iso_frame_desc[0].length;
 678
 679                 if (u == 0) {
 680                         int now;
 681                         struct usb_device *dev = inurb->dev;
 682                         frame = usb_get_current_frame_number(dev);
 683                         do {
 684                                 now = usb_get_current_frame_number(dev);
 685                                 ++iters;
 686                         } while (now > -1 && now == frame);
 687                 }
 688                 err = usb_submit_urb(inurb, GFP_ATOMIC);
 689                 if (err < 0) {
 690                         snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
 691                                    " returned %i\n", u, err);
 692                         return err;
 693                 }
 694                 err = usb_submit_urb(outurb, GFP_ATOMIC);
 695                 if (err < 0) {
 696                         snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
 697                                    " returned %i\n", u, err);
 698                         return err;
 699                 }
 700
 701                 if (inurb->start_frame != outurb->start_frame) {
 702                         snd_printd(KERN_DEBUG
 703                                    "u[%i] start_frames differ in:%u out:%u\n",
 704                                    u, inurb->start_frame, outurb->start_frame);
 705                         goto check_retry;
 706                 }
 707         }
 708         snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
 709         try = 0;
 710 check_retry:
 711         if (try) {
 712                 usb_stream_stop(sk);
 713                 if (try < 5) {
 714                         msleep(1500);
 715                         snd_printd(KERN_DEBUG "goto dotry;\n");
 716                         goto dotry;
 717                 }
 718                 snd_printk(KERN_WARNING"couldn't start"
 719                            " all urbs on the same start_frame.\n");
 720                 return -EFAULT;
 721         }
 722
 723         sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
 724         sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
 725         sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
 726         sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
 727
 728 /* wait, check */
 729         {
 730                 int wait_ms = 3000;
 731                 while (s->state != usb_stream_ready && wait_ms > 0) {
 732                         snd_printdd(KERN_DEBUG "%i\n", s->state);
 733                         msleep(200);
 734                         wait_ms -= 200;
 735                 }
 736         }
 737
 738         return s->state == usb_stream_ready ? 0 : -EFAULT;
 739 }
 740
 741
 742 /*                             stop                                   */
 743
 744 void usb_stream_stop(struct usb_stream_kernel *sk)
 745 {
 746         int u;
 747         if (!sk->s)
 748                 return;
 749         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 750                 usb_kill_urb(sk->inurb[u]);
 751                 usb_kill_urb(sk->outurb[u]);
 752         }
 753         sk->s->state = usb_stream_stopped;
 754         msleep(400);
 755 }