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 int 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                 if (usb_urb_ep_type_check(urb))
  81                         return -EINVAL;
  82
  83                 urb->transfer_buffer_length = transfer_length;
  84                 desc = urb->iso_frame_desc;
  85                 desc->offset = 0;
  86                 desc->length = maxpacket;
  87                 for (p = 1; p < sk->n_o_ps; ++p) {
  88                         desc[p].offset = desc[p - 1].offset + maxpacket;
  89                         desc[p].length = maxpacket;
  90                 }
  91         }
  92
  93         return 0;
  94 }
  95
  96 static int init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
  97                       struct usb_device *dev, int in_pipe, int out_pipe)
  98 {
  99         struct usb_stream       *s = sk->s;
 100         char                    *indata = (char *)s + sizeof(*s) +
 101                                         sizeof(struct usb_stream_packet) *
 102                                         s->inpackets;
 103         int                     u;
 104
 105         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 106                 sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
 107                 if (!sk->inurb[u])
 108                         return -ENOMEM;
 109
 110                 sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
 111                 if (!sk->outurb[u])
 112                         return -ENOMEM;
 113         }
 114
 115         if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
 116             init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
 117                            out_pipe))
 118                 return -EINVAL;
 119
 120         return 0;
 121 }
 122
 123
 124 /*
 125  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
 126  * this will overflow at approx 524 kHz
 127  */
 128 static inline unsigned get_usb_full_speed_rate(unsigned rate)
 129 {
 130         return ((rate << 13) + 62) / 125;
 131 }
 132
 133 /*
 134  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
 135  * this will overflow at approx 4 MHz
 136  */
 137 static inline unsigned get_usb_high_speed_rate(unsigned rate)
 138 {
 139         return ((rate << 10) + 62) / 125;
 140 }
 141
 142 void usb_stream_free(struct usb_stream_kernel *sk)
 143 {
 144         struct usb_stream *s;
 145         unsigned u;
 146
 147         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 148                 usb_free_urb(sk->inurb[u]);
 149                 sk->inurb[u] = NULL;
 150                 usb_free_urb(sk->outurb[u]);
 151                 sk->outurb[u] = NULL;
 152         }
 153
 154         s = sk->s;
 155         if (!s)
 156                 return;
 157
 158         free_pages((unsigned long)sk->write_page, get_order(s->write_size));
 159         sk->write_page = NULL;
 160         free_pages((unsigned long)s, get_order(s->read_size));
 161         sk->s = NULL;
 162 }
 163
 164 struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
 165                                   struct usb_device *dev,
 166                                   unsigned in_endpoint, unsigned out_endpoint,
 167                                   unsigned sample_rate, unsigned use_packsize,
 168                                   unsigned period_frames, unsigned frame_size)
 169 {
 170         int packets, max_packsize;
 171         int in_pipe, out_pipe;
 172         int read_size = sizeof(struct usb_stream);
 173         int write_size;
 174         int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
 175         int pg;
 176
 177         in_pipe = usb_rcvisocpipe(dev, in_endpoint);
 178         out_pipe = usb_sndisocpipe(dev, out_endpoint);
 179
 180         max_packsize = use_packsize ?
 181                 use_packsize : usb_maxpacket(dev, in_pipe, 0);
 182
 183         /*
 184                 t_period = period_frames / sample_rate
 185                 iso_packs = t_period / t_iso_frame
 186                         = (period_frames / sample_rate) * (1 / t_iso_frame)
 187         */
 188
 189         packets = period_frames * usb_frames / sample_rate + 1;
 190
 191         if (dev->speed == USB_SPEED_HIGH)
 192                 packets = (packets + 7) & ~7;
 193
 194         read_size += packets * USB_STREAM_URBDEPTH *
 195                 (max_packsize + sizeof(struct usb_stream_packet));
 196
 197         max_packsize = usb_maxpacket(dev, out_pipe, 1);
 198         write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
 199
 200         if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
 201                 snd_printk(KERN_WARNING "a size exceeds 128*PAGE_SIZE\n");
 202                 goto out;
 203         }
 204
 205         pg = get_order(read_size);
 206         sk->s = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO|
 207                                           __GFP_NOWARN, pg);
 208         if (!sk->s) {
 209                 snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
 210                 goto out;
 211         }
 212         sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
 213
 214         sk->s->read_size = read_size;
 215
 216         sk->s->cfg.sample_rate = sample_rate;
 217         sk->s->cfg.frame_size = frame_size;
 218         sk->n_o_ps = packets;
 219         sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
 220         sk->s->cfg.period_frames = period_frames;
 221         sk->s->period_size = frame_size * period_frames;
 222
 223         sk->s->write_size = write_size;
 224         pg = get_order(write_size);
 225
 226         sk->write_page =
 227                 (void *)__get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO|
 228                                          __GFP_NOWARN, pg);
 229         if (!sk->write_page) {
 230                 snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
 231                 usb_stream_free(sk);
 232                 return NULL;
 233         }
 234
 235         /* calculate the frequency in 16.16 format */
 236         if (dev->speed == USB_SPEED_FULL)
 237                 sk->freqn = get_usb_full_speed_rate(sample_rate);
 238         else
 239                 sk->freqn = get_usb_high_speed_rate(sample_rate);
 240
 241         if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
 242                 usb_stream_free(sk);
 243                 return NULL;
 244         }
 245
 246         sk->s->state = usb_stream_stopped;
 247 out:
 248         return sk->s;
 249 }
 250
 251
 252 /*                             start                                  */
 253
 254 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
 255 {
 256         bool r;
 257         if (unlikely(urb->status)) {
 258                 if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
 259                         snd_printk(KERN_WARNING "status=%i\n", urb->status);
 260                 sk->iso_frame_balance = 0x7FFFFFFF;
 261                 return false;
 262         }
 263         r = sk->iso_frame_balance == 0;
 264         if (!r)
 265                 sk->i_urb = urb;
 266         return r;
 267 }
 268
 269 static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
 270 {
 271         sk->iso_frame_balance += urb->number_of_packets;
 272         return balance_check(sk, urb);
 273 }
 274
 275 static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
 276 {
 277         sk->iso_frame_balance -= urb->number_of_packets;
 278         return balance_check(sk, urb);
 279 }
 280
 281 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
 282 {
 283         int u;
 284
 285         for (u = 0; u < USB_STREAM_NURBS; u++) {
 286                 struct urb *urb = urbs[u];
 287                 urb->complete = complete;
 288         }
 289 }
 290
 291 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
 292                 struct urb *inurb)
 293 {
 294         struct usb_stream *s = sk->s;
 295         struct urb *io;
 296         struct usb_iso_packet_descriptor *id, *od;
 297         int p = 0, lb = 0, l = 0;
 298
 299         io = sk->idle_outurb;
 300         od = io->iso_frame_desc;
 301
 302         for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
 303                 struct urb *ii = sk->completed_inurb;
 304                 id = ii->iso_frame_desc +
 305                         ii->number_of_packets + s->sync_packet;
 306                 l = id->actual_length;
 307
 308                 od[p].length = l;
 309                 od[p].offset = lb;
 310                 lb += l;
 311         }
 312
 313         for (;
 314              s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
 315              ++p, ++s->sync_packet) {
 316                 l = inurb->iso_frame_desc[s->sync_packet].actual_length;
 317
 318                 if (s->idle_outsize + lb + l > s->period_size)
 319                         goto check_ok;
 320
 321                 od[p].length = l;
 322                 od[p].offset = lb;
 323                 lb += l;
 324         }
 325
 326 check_ok:
 327         s->sync_packet -= inurb->number_of_packets;
 328         if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
 329                 snd_printk(KERN_WARNING "invalid sync_packet = %i;"
 330                            " p=%i nop=%i %i %x %x %x > %x\n",
 331                            s->sync_packet, p, inurb->number_of_packets,
 332                            s->idle_outsize + lb + l,
 333                            s->idle_outsize, lb,  l,
 334                            s->period_size);
 335                 return -1;
 336         }
 337         if (unlikely(lb % s->cfg.frame_size)) {
 338                 snd_printk(KERN_WARNING"invalid outsize = %i\n",
 339                            lb);
 340                 return -1;
 341         }
 342         s->idle_outsize += lb - s->period_size;
 343         io->number_of_packets = p;
 344         io->transfer_buffer_length = lb;
 345         if (s->idle_outsize <= 0)
 346                 return 0;
 347
 348         snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
 349         return -1;
 350 }
 351
 352 static void prepare_inurb(int number_of_packets, struct urb *iu)
 353 {
 354         struct usb_iso_packet_descriptor *id;
 355         int p;
 356
 357         iu->number_of_packets = number_of_packets;
 358         id = iu->iso_frame_desc;
 359         id->offset = 0;
 360         for (p = 0; p < iu->number_of_packets - 1; ++p)
 361                 id[p + 1].offset = id[p].offset + id[p].length;
 362
 363         iu->transfer_buffer_length =
 364                 id[0].length * iu->number_of_packets;
 365 }
 366
 367 static int submit_urbs(struct usb_stream_kernel *sk,
 368                        struct urb *inurb, struct urb *outurb)
 369 {
 370         int err;
 371         prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
 372         err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
 373         if (err < 0)
 374                 goto report_failure;
 375
 376         sk->idle_inurb = sk->completed_inurb;
 377         sk->completed_inurb = inurb;
 378         err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
 379         if (err < 0)
 380                 goto report_failure;
 381
 382         sk->idle_outurb = sk->completed_outurb;
 383         sk->completed_outurb = outurb;
 384         return 0;
 385
 386 report_failure:
 387         snd_printk(KERN_ERR "%i\n", err);
 388         return err;
 389 }
 390
 391 #ifdef DEBUG_LOOP_BACK
 392 /*
 393   This loop_back() shows how to read/write the period data.
 394  */
 395 static void loop_back(struct usb_stream *s)
 396 {
 397         char *i, *o;
 398         int il, ol, l, p;
 399         struct urb *iu;
 400         struct usb_iso_packet_descriptor *id;
 401
 402         o = s->playback1st_to;
 403         ol = s->playback1st_size;
 404         l = 0;
 405
 406         if (s->insplit_pack >= 0) {
 407                 iu = sk->idle_inurb;
 408                 id = iu->iso_frame_desc;
 409                 p = s->insplit_pack;
 410         } else
 411                 goto second;
 412 loop:
 413         for (; p < iu->number_of_packets && l < s->period_size; ++p) {
 414                 i = iu->transfer_buffer + id[p].offset;
 415                 il = id[p].actual_length;
 416                 if (l + il > s->period_size)
 417                         il = s->period_size - l;
 418                 if (il <= ol) {
 419                         memcpy(o, i, il);
 420                         o += il;
 421                         ol -= il;
 422                 } else {
 423                         memcpy(o, i, ol);
 424                         singen_6pack(o, ol);
 425                         o = s->playback_to;
 426                         memcpy(o, i + ol, il - ol);
 427                         o += il - ol;
 428                         ol = s->period_size - s->playback1st_size;
 429                 }
 430                 l += il;
 431         }
 432         if (iu == sk->completed_inurb) {
 433                 if (l != s->period_size)
 434                         printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
 435                                l/(int)s->cfg.frame_size);
 436
 437                 return;
 438         }
 439 second:
 440         iu = sk->completed_inurb;
 441         id = iu->iso_frame_desc;
 442         p = 0;
 443         goto loop;
 444
 445 }
 446 #else
 447 static void loop_back(struct usb_stream *s)
 448 {
 449 }
 450 #endif
 451
 452 static void stream_idle(struct usb_stream_kernel *sk,
 453                         struct urb *inurb, struct urb *outurb)
 454 {
 455         struct usb_stream *s = sk->s;
 456         int l, p;
 457         int insize = s->idle_insize;
 458         int urb_size = 0;
 459
 460         s->inpacket_split = s->next_inpacket_split;
 461         s->inpacket_split_at = s->next_inpacket_split_at;
 462         s->next_inpacket_split = -1;
 463         s->next_inpacket_split_at = 0;
 464
 465         for (p = 0; p < inurb->number_of_packets; ++p) {
 466                 struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
 467                 l = id[p].actual_length;
 468                 if (unlikely(l == 0 || id[p].status)) {
 469                         snd_printk(KERN_WARNING "underrun, status=%u\n",
 470                                    id[p].status);
 471                         goto err_out;
 472                 }
 473                 s->inpacket_head++;
 474                 s->inpacket_head %= s->inpackets;
 475                 if (s->inpacket_split == -1)
 476                         s->inpacket_split = s->inpacket_head;
 477
 478                 s->inpacket[s->inpacket_head].offset =
 479                         id[p].offset + (inurb->transfer_buffer - (void *)s);
 480                 s->inpacket[s->inpacket_head].length = l;
 481                 if (insize + l > s->period_size &&
 482                     s->next_inpacket_split == -1) {
 483                         s->next_inpacket_split = s->inpacket_head;
 484                         s->next_inpacket_split_at = s->period_size - insize;
 485                 }
 486                 insize += l;
 487                 urb_size += l;
 488         }
 489         s->idle_insize += urb_size - s->period_size;
 490         if (s->idle_insize < 0) {
 491                 snd_printk(KERN_WARNING "%i\n",
 492                            (s->idle_insize)/(int)s->cfg.frame_size);
 493                 goto err_out;
 494         }
 495         s->insize_done += urb_size;
 496
 497         l = s->idle_outsize;
 498         s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
 499                                   sk->write_page) - l;
 500
 501         if (usb_stream_prepare_playback(sk, inurb) < 0)
 502                 goto err_out;
 503
 504         s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
 505         s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
 506                 sk->write_page;
 507
 508         if (submit_urbs(sk, inurb, outurb) < 0)
 509                 goto err_out;
 510
 511         loop_back(s);
 512         s->periods_done++;
 513         wake_up_all(&sk->sleep);
 514         return;
 515 err_out:
 516         s->state = usb_stream_xrun;
 517         wake_up_all(&sk->sleep);
 518 }
 519
 520 static void i_capture_idle(struct urb *urb)
 521 {
 522         struct usb_stream_kernel *sk = urb->context;
 523         if (balance_capture(sk, urb))
 524                 stream_idle(sk, urb, sk->i_urb);
 525 }
 526
 527 static void i_playback_idle(struct urb *urb)
 528 {
 529         struct usb_stream_kernel *sk = urb->context;
 530         if (balance_playback(sk, urb))
 531                 stream_idle(sk, sk->i_urb, urb);
 532 }
 533
 534 static void stream_start(struct usb_stream_kernel *sk,
 535                          struct urb *inurb, struct urb *outurb)
 536 {
 537         struct usb_stream *s = sk->s;
 538         if (s->state >= usb_stream_sync1) {
 539                 int l, p, max_diff, max_diff_0;
 540                 int urb_size = 0;
 541                 unsigned frames_per_packet, min_frames = 0;
 542                 frames_per_packet = (s->period_size - s->idle_insize);
 543                 frames_per_packet <<= 8;
 544                 frames_per_packet /=
 545                         s->cfg.frame_size * inurb->number_of_packets;
 546                 frames_per_packet++;
 547
 548                 max_diff_0 = s->cfg.frame_size;
 549                 if (s->cfg.period_frames >= 256)
 550                         max_diff_0 <<= 1;
 551                 if (s->cfg.period_frames >= 1024)
 552                         max_diff_0 <<= 1;
 553                 max_diff = max_diff_0;
 554                 for (p = 0; p < inurb->number_of_packets; ++p) {
 555                         int diff;
 556                         l = inurb->iso_frame_desc[p].actual_length;
 557                         urb_size += l;
 558
 559                         min_frames += frames_per_packet;
 560                         diff = urb_size -
 561                                 (min_frames >> 8) * s->cfg.frame_size;
 562                         if (diff < max_diff) {
 563                                 snd_printdd(KERN_DEBUG "%i %i %i %i\n",
 564                                             s->insize_done,
 565                                             urb_size / (int)s->cfg.frame_size,
 566                                             inurb->number_of_packets, diff);
 567                                 max_diff = diff;
 568                         }
 569                 }
 570                 s->idle_insize -= max_diff - max_diff_0;
 571                 s->idle_insize += urb_size - s->period_size;
 572                 if (s->idle_insize < 0) {
 573                         snd_printk(KERN_WARNING "%i %i %i\n",
 574                                    s->idle_insize, urb_size, s->period_size);
 575                         return;
 576                 } else if (s->idle_insize == 0) {
 577                         s->next_inpacket_split =
 578                                 (s->inpacket_head + 1) % s->inpackets;
 579                         s->next_inpacket_split_at = 0;
 580                 } else {
 581                         unsigned split = s->inpacket_head;
 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                 if (l < s->cfg.frame_size) {
 630                         ++empty;
 631                         if (s->state >= usb_stream_sync0) {
 632                                 snd_printk(KERN_WARNING "%i\n", l);
 633                                 return;
 634                         }
 635                 }
 636                 s->inpacket_head++;
 637                 s->inpacket_head %= s->inpackets;
 638                 s->inpacket[s->inpacket_head].offset =
 639                         id[p].offset + (urb->transfer_buffer - (void *)s);
 640                 s->inpacket[s->inpacket_head].length = l;
 641         }
 642 #ifdef SHOW_EMPTY
 643         if (empty) {
 644                 printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
 645                        urb->iso_frame_desc[0].actual_length);
 646                 for (pack = 1; pack < urb->number_of_packets; ++pack) {
 647                         int l = urb->iso_frame_desc[pack].actual_length;
 648                         printk(KERN_CONT " %i", l);
 649                 }
 650                 printk(KERN_CONT "\n");
 651         }
 652 #endif
 653         if (!empty && s->state < usb_stream_sync1)
 654                 ++s->state;
 655
 656         if (balance_capture(sk, urb))
 657                 stream_start(sk, urb, sk->i_urb);
 658 }
 659
 660 static void i_playback_start(struct urb *urb)
 661 {
 662         struct usb_stream_kernel *sk = urb->context;
 663         if (balance_playback(sk, urb))
 664                 stream_start(sk, sk->i_urb, urb);
 665 }
 666
 667 int usb_stream_start(struct usb_stream_kernel *sk)
 668 {
 669         struct usb_stream *s = sk->s;
 670         int frame = 0, iters = 0;
 671         int u, err;
 672         int try = 0;
 673
 674         if (s->state != usb_stream_stopped)
 675                 return -EAGAIN;
 676
 677         subs_set_complete(sk->inurb, i_capture_start);
 678         subs_set_complete(sk->outurb, i_playback_start);
 679         memset(sk->write_page, 0, s->write_size);
 680 dotry:
 681         s->insize_done = 0;
 682         s->idle_insize = 0;
 683         s->idle_outsize = 0;
 684         s->sync_packet = -1;
 685         s->inpacket_head = -1;
 686         sk->iso_frame_balance = 0;
 687         ++try;
 688         for (u = 0; u < 2; u++) {
 689                 struct urb *inurb = sk->inurb[u];
 690                 struct urb *outurb = sk->outurb[u];
 691                 playback_prep_freqn(sk, outurb);
 692                 inurb->number_of_packets = outurb->number_of_packets;
 693                 inurb->transfer_buffer_length =
 694                         inurb->number_of_packets *
 695                         inurb->iso_frame_desc[0].length;
 696
 697                 if (u == 0) {
 698                         int now;
 699                         struct usb_device *dev = inurb->dev;
 700                         frame = usb_get_current_frame_number(dev);
 701                         do {
 702                                 now = usb_get_current_frame_number(dev);
 703                                 ++iters;
 704                         } while (now > -1 && now == frame);
 705                 }
 706                 err = usb_submit_urb(inurb, GFP_ATOMIC);
 707                 if (err < 0) {
 708                         snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
 709                                    " returned %i\n", u, err);
 710                         return err;
 711                 }
 712                 err = usb_submit_urb(outurb, GFP_ATOMIC);
 713                 if (err < 0) {
 714                         snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
 715                                    " returned %i\n", u, err);
 716                         return err;
 717                 }
 718
 719                 if (inurb->start_frame != outurb->start_frame) {
 720                         snd_printd(KERN_DEBUG
 721                                    "u[%i] start_frames differ in:%u out:%u\n",
 722                                    u, inurb->start_frame, outurb->start_frame);
 723                         goto check_retry;
 724                 }
 725         }
 726         snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
 727         try = 0;
 728 check_retry:
 729         if (try) {
 730                 usb_stream_stop(sk);
 731                 if (try < 5) {
 732                         msleep(1500);
 733                         snd_printd(KERN_DEBUG "goto dotry;\n");
 734                         goto dotry;
 735                 }
 736                 snd_printk(KERN_WARNING"couldn't start"
 737                            " all urbs on the same start_frame.\n");
 738                 return -EFAULT;
 739         }
 740
 741         sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
 742         sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
 743         sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
 744         sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
 745
 746 /* wait, check */
 747         {
 748                 int wait_ms = 3000;
 749                 while (s->state != usb_stream_ready && wait_ms > 0) {
 750                         snd_printdd(KERN_DEBUG "%i\n", s->state);
 751                         msleep(200);
 752                         wait_ms -= 200;
 753                 }
 754         }
 755
 756         return s->state == usb_stream_ready ? 0 : -EFAULT;
 757 }
 758
 759
 760 /*                             stop                                   */
 761
 762 void usb_stream_stop(struct usb_stream_kernel *sk)
 763 {
 764         int u;
 765         if (!sk->s)
 766                 return;
 767         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 768                 usb_kill_urb(sk->inurb[u]);
 769                 usb_kill_urb(sk->outurb[u]);
 770         }
 771         sk->s->state = usb_stream_stopped;
 772         msleep(400);
 773 }