kernel/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, pg);
 195         if (!sk->s) {
 196                 snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
 197                 goto out;
 198         }
 199         sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
 200
 201         sk->s->read_size = read_size;
 202
 203         sk->s->cfg.sample_rate = sample_rate;
 204         sk->s->cfg.frame_size = frame_size;
 205         sk->n_o_ps = packets;
 206         sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
 207         sk->s->cfg.period_frames = period_frames;
 208         sk->s->period_size = frame_size * period_frames;
 209
 210         sk->s->write_size = write_size;
 211         pg = get_order(write_size);
 212
 213         sk->write_page =
 214                 (void *)__get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO, pg);
 215         if (!sk->write_page) {
 216                 snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
 217                 usb_stream_free(sk);
 218                 return NULL;
 219         }
 220
 221         /* calculate the frequency in 16.16 format */
 222         if (dev->speed == USB_SPEED_FULL)
 223                 sk->freqn = get_usb_full_speed_rate(sample_rate);
 224         else
 225                 sk->freqn = get_usb_high_speed_rate(sample_rate);
 226
 227         init_urbs(sk, use_packsize, dev, in_pipe, out_pipe);
 228         sk->s->state = usb_stream_stopped;
 229 out:
 230         return sk->s;
 231 }
 232
 233
 234 /*                             start                                  */
 235
 236 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
 237 {
 238         bool r;
 239         if (unlikely(urb->status)) {
 240                 if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
 241                         snd_printk(KERN_WARNING "status=%i\n", urb->status);
 242                 sk->iso_frame_balance = 0x7FFFFFFF;
 243                 return false;
 244         }
 245         r = sk->iso_frame_balance == 0;
 246         if (!r)
 247                 sk->i_urb = urb;
 248         return r;
 249 }
 250
 251 static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
 252 {
 253         sk->iso_frame_balance += urb->number_of_packets;
 254         return balance_check(sk, urb);
 255 }
 256
 257 static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
 258 {
 259         sk->iso_frame_balance -= urb->number_of_packets;
 260         return balance_check(sk, urb);
 261 }
 262
 263 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
 264 {
 265         int u;
 266
 267         for (u = 0; u < USB_STREAM_NURBS; u++) {
 268                 struct urb *urb = urbs[u];
 269                 urb->complete = complete;
 270         }
 271 }
 272
 273 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
 274                 struct urb *inurb)
 275 {
 276         struct usb_stream *s = sk->s;
 277         struct urb *io;
 278         struct usb_iso_packet_descriptor *id, *od;
 279         int p = 0, lb = 0, l = 0;
 280
 281         io = sk->idle_outurb;
 282         od = io->iso_frame_desc;
 283
 284         for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
 285                 struct urb *ii = sk->completed_inurb;
 286                 id = ii->iso_frame_desc +
 287                         ii->number_of_packets + s->sync_packet;
 288                 l = id->actual_length;
 289
 290                 od[p].length = l;
 291                 od[p].offset = lb;
 292                 lb += l;
 293         }
 294
 295         for (;
 296              s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
 297              ++p, ++s->sync_packet) {
 298                 l = inurb->iso_frame_desc[s->sync_packet].actual_length;
 299
 300                 if (s->idle_outsize + lb + l > s->period_size)
 301                         goto check_ok;
 302
 303                 od[p].length = l;
 304                 od[p].offset = lb;
 305                 lb += l;
 306         }
 307
 308 check_ok:
 309         s->sync_packet -= inurb->number_of_packets;
 310         if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
 311                 snd_printk(KERN_WARNING "invalid sync_packet = %i;"
 312                            " p=%i nop=%i %i %x %x %x > %x\n",
 313                            s->sync_packet, p, inurb->number_of_packets,
 314                            s->idle_outsize + lb + l,
 315                            s->idle_outsize, lb,  l,
 316                            s->period_size);
 317                 return -1;
 318         }
 319         if (unlikely(lb % s->cfg.frame_size)) {
 320                 snd_printk(KERN_WARNING"invalid outsize = %i\n",
 321                            lb);
 322                 return -1;
 323         }
 324         s->idle_outsize += lb - s->period_size;
 325         io->number_of_packets = p;
 326         io->transfer_buffer_length = lb;
 327         if (s->idle_outsize <= 0)
 328                 return 0;
 329
 330         snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
 331         return -1;
 332 }
 333
 334 static void prepare_inurb(int number_of_packets, struct urb *iu)
 335 {
 336         struct usb_iso_packet_descriptor *id;
 337         int p;
 338
 339         iu->number_of_packets = number_of_packets;
 340         id = iu->iso_frame_desc;
 341         id->offset = 0;
 342         for (p = 0; p < iu->number_of_packets - 1; ++p)
 343                 id[p + 1].offset = id[p].offset + id[p].length;
 344
 345         iu->transfer_buffer_length =
 346                 id[0].length * iu->number_of_packets;
 347 }
 348
 349 static int submit_urbs(struct usb_stream_kernel *sk,
 350                        struct urb *inurb, struct urb *outurb)
 351 {
 352         int err;
 353         prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
 354         err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
 355         if (err < 0) {
 356                 snd_printk(KERN_ERR "%i\n", err);
 357                 return err;
 358         }
 359         sk->idle_inurb = sk->completed_inurb;
 360         sk->completed_inurb = inurb;
 361         err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
 362         if (err < 0) {
 363                 snd_printk(KERN_ERR "%i\n", err);
 364                 return err;
 365         }
 366         sk->idle_outurb = sk->completed_outurb;
 367         sk->completed_outurb = outurb;
 368         return 0;
 369 }
 370
 371 #ifdef DEBUG_LOOP_BACK
 372 /*
 373   This loop_back() shows how to read/write the period data.
 374  */
 375 static void loop_back(struct usb_stream *s)
 376 {
 377         char *i, *o;
 378         int il, ol, l, p;
 379         struct urb *iu;
 380         struct usb_iso_packet_descriptor *id;
 381
 382         o = s->playback1st_to;
 383         ol = s->playback1st_size;
 384         l = 0;
 385
 386         if (s->insplit_pack >= 0) {
 387                 iu = sk->idle_inurb;
 388                 id = iu->iso_frame_desc;
 389                 p = s->insplit_pack;
 390         } else
 391                 goto second;
 392 loop:
 393         for (; p < iu->number_of_packets && l < s->period_size; ++p) {
 394                 i = iu->transfer_buffer + id[p].offset;
 395                 il = id[p].actual_length;
 396                 if (l + il > s->period_size)
 397                         il = s->period_size - l;
 398                 if (il <= ol) {
 399                         memcpy(o, i, il);
 400                         o += il;
 401                         ol -= il;
 402                 } else {
 403                         memcpy(o, i, ol);
 404                         singen_6pack(o, ol);
 405                         o = s->playback_to;
 406                         memcpy(o, i + ol, il - ol);
 407                         o += il - ol;
 408                         ol = s->period_size - s->playback1st_size;
 409                 }
 410                 l += il;
 411         }
 412         if (iu == sk->completed_inurb) {
 413                 if (l != s->period_size)
 414                         printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
 415                                l/(int)s->cfg.frame_size);
 416
 417                 return;
 418         }
 419 second:
 420         iu = sk->completed_inurb;
 421         id = iu->iso_frame_desc;
 422         p = 0;
 423         goto loop;
 424
 425 }
 426 #else
 427 static void loop_back(struct usb_stream *s)
 428 {
 429 }
 430 #endif
 431
 432 static void stream_idle(struct usb_stream_kernel *sk,
 433                         struct urb *inurb, struct urb *outurb)
 434 {
 435         struct usb_stream *s = sk->s;
 436         int l, p;
 437         int insize = s->idle_insize;
 438         int urb_size = 0;
 439
 440         s->inpacket_split = s->next_inpacket_split;
 441         s->inpacket_split_at = s->next_inpacket_split_at;
 442         s->next_inpacket_split = -1;
 443         s->next_inpacket_split_at = 0;
 444
 445         for (p = 0; p < inurb->number_of_packets; ++p) {
 446                 struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
 447                 l = id[p].actual_length;
 448                 if (unlikely(l == 0 || id[p].status)) {
 449                         snd_printk(KERN_WARNING "underrun, status=%u\n",
 450                                    id[p].status);
 451                         goto err_out;
 452                 }
 453                 s->inpacket_head++;
 454                 s->inpacket_head %= s->inpackets;
 455                 if (s->inpacket_split == -1)
 456                         s->inpacket_split = s->inpacket_head;
 457
 458                 s->inpacket[s->inpacket_head].offset =
 459                         id[p].offset + (inurb->transfer_buffer - (void *)s);
 460                 s->inpacket[s->inpacket_head].length = l;
 461                 if (insize + l > s->period_size &&
 462                     s->next_inpacket_split == -1) {
 463                         s->next_inpacket_split = s->inpacket_head;
 464                         s->next_inpacket_split_at = s->period_size - insize;
 465                 }
 466                 insize += l;
 467                 urb_size += l;
 468         }
 469         s->idle_insize += urb_size - s->period_size;
 470         if (s->idle_insize < 0) {
 471                 snd_printk(KERN_WARNING "%i\n",
 472                            (s->idle_insize)/(int)s->cfg.frame_size);
 473                 goto err_out;
 474         }
 475         s->insize_done += urb_size;
 476
 477         l = s->idle_outsize;
 478         s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
 479                                   sk->write_page) - l;
 480
 481         if (usb_stream_prepare_playback(sk, inurb) < 0)
 482                 goto err_out;
 483
 484         s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
 485         s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
 486                 sk->write_page;
 487
 488         if (submit_urbs(sk, inurb, outurb) < 0)
 489                 goto err_out;
 490
 491         loop_back(s);
 492         s->periods_done++;
 493         wake_up_all(&sk->sleep);
 494         return;
 495 err_out:
 496         s->state = usb_stream_xrun;
 497         wake_up_all(&sk->sleep);
 498 }
 499
 500 static void i_capture_idle(struct urb *urb)
 501 {
 502         struct usb_stream_kernel *sk = urb->context;
 503         if (balance_capture(sk, urb))
 504                 stream_idle(sk, urb, sk->i_urb);
 505 }
 506
 507 static void i_playback_idle(struct urb *urb)
 508 {
 509         struct usb_stream_kernel *sk = urb->context;
 510         if (balance_playback(sk, urb))
 511                 stream_idle(sk, sk->i_urb, urb);
 512 }
 513
 514 static void stream_start(struct usb_stream_kernel *sk,
 515                          struct urb *inurb, struct urb *outurb)
 516 {
 517         struct usb_stream *s = sk->s;
 518         if (s->state >= usb_stream_sync1) {
 519                 int l, p, max_diff, max_diff_0;
 520                 int urb_size = 0;
 521                 unsigned frames_per_packet, min_frames = 0;
 522                 frames_per_packet = (s->period_size - s->idle_insize);
 523                 frames_per_packet <<= 8;
 524                 frames_per_packet /=
 525                         s->cfg.frame_size * inurb->number_of_packets;
 526                 frames_per_packet++;
 527
 528                 max_diff_0 = s->cfg.frame_size;
 529                 if (s->cfg.period_frames >= 256)
 530                         max_diff_0 <<= 1;
 531                 if (s->cfg.period_frames >= 1024)
 532                         max_diff_0 <<= 1;
 533                 max_diff = max_diff_0;
 534                 for (p = 0; p < inurb->number_of_packets; ++p) {
 535                         int diff;
 536                         l = inurb->iso_frame_desc[p].actual_length;
 537                         urb_size += l;
 538
 539                         min_frames += frames_per_packet;
 540                         diff = urb_size -
 541                                 (min_frames >> 8) * s->cfg.frame_size;
 542                         if (diff < max_diff) {
 543                                 snd_printdd(KERN_DEBUG "%i %i %i %i\n",
 544                                             s->insize_done,
 545                                             urb_size / (int)s->cfg.frame_size,
 546                                             inurb->number_of_packets, diff);
 547                                 max_diff = diff;
 548                         }
 549                 }
 550                 s->idle_insize -= max_diff - max_diff_0;
 551                 s->idle_insize += urb_size - s->period_size;
 552                 if (s->idle_insize < 0) {
 553                         snd_printk(KERN_WARNING "%i %i %i\n",
 554                                    s->idle_insize, urb_size, s->period_size);
 555                         return;
 556                 } else if (s->idle_insize == 0) {
 557                         s->next_inpacket_split =
 558                                 (s->inpacket_head + 1) % s->inpackets;
 559                         s->next_inpacket_split_at = 0;
 560                 } else {
 561                         unsigned split = s->inpacket_head;
 562                         l = s->idle_insize;
 563                         while (l > s->inpacket[split].length) {
 564                                 l -= s->inpacket[split].length;
 565                                 if (split == 0)
 566                                         split = s->inpackets - 1;
 567                                 else
 568                                         split--;
 569                         }
 570                         s->next_inpacket_split = split;
 571                         s->next_inpacket_split_at =
 572                                 s->inpacket[split].length - l;
 573                 }
 574
 575                 s->insize_done += urb_size;
 576
 577                 if (usb_stream_prepare_playback(sk, inurb) < 0)
 578                         return;
 579
 580         } else
 581                 playback_prep_freqn(sk, sk->idle_outurb);
 582
 583         if (submit_urbs(sk, inurb, outurb) < 0)
 584                 return;
 585
 586         if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
 587                 /* just guesswork                            ^^^^^^ */
 588                 s->state = usb_stream_ready;
 589                 subs_set_complete(sk->inurb, i_capture_idle);
 590                 subs_set_complete(sk->outurb, i_playback_idle);
 591         }
 592 }
 593
 594 static void i_capture_start(struct urb *urb)
 595 {
 596         struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
 597         struct usb_stream_kernel *sk = urb->context;
 598         struct usb_stream *s = sk->s;
 599         int p;
 600         int empty = 0;
 601
 602         if (urb->status) {
 603                 snd_printk(KERN_WARNING "status=%i\n", urb->status);
 604                 return;
 605         }
 606
 607         for (p = 0; p < urb->number_of_packets; ++p) {
 608                 int l = id[p].actual_length;
 609                 if (l < s->cfg.frame_size) {
 610                         ++empty;
 611                         if (s->state >= usb_stream_sync0) {
 612                                 snd_printk(KERN_WARNING "%i\n", l);
 613                                 return;
 614                         }
 615                 }
 616                 s->inpacket_head++;
 617                 s->inpacket_head %= s->inpackets;
 618                 s->inpacket[s->inpacket_head].offset =
 619                         id[p].offset + (urb->transfer_buffer - (void *)s);
 620                 s->inpacket[s->inpacket_head].length = l;
 621         }
 622 #ifdef SHOW_EMPTY
 623         if (empty) {
 624                 printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
 625                        urb->iso_frame_desc[0].actual_length);
 626                 for (pack = 1; pack < urb->number_of_packets; ++pack) {
 627                         int l = urb->iso_frame_desc[pack].actual_length;
 628                         printk(" %i", l);
 629                 }
 630                 printk("\n");
 631         }
 632 #endif
 633         if (!empty && s->state < usb_stream_sync1)
 634                 ++s->state;
 635
 636         if (balance_capture(sk, urb))
 637                 stream_start(sk, urb, sk->i_urb);
 638 }
 639
 640 static void i_playback_start(struct urb *urb)
 641 {
 642         struct usb_stream_kernel *sk = urb->context;
 643         if (balance_playback(sk, urb))
 644                 stream_start(sk, sk->i_urb, urb);
 645 }
 646
 647 int usb_stream_start(struct usb_stream_kernel *sk)
 648 {
 649         struct usb_stream *s = sk->s;
 650         int frame = 0, iters = 0;
 651         int u, err;
 652         int try = 0;
 653
 654         if (s->state != usb_stream_stopped)
 655                 return -EAGAIN;
 656
 657         subs_set_complete(sk->inurb, i_capture_start);
 658         subs_set_complete(sk->outurb, i_playback_start);
 659         memset(sk->write_page, 0, s->write_size);
 660 dotry:
 661         s->insize_done = 0;
 662         s->idle_insize = 0;
 663         s->idle_outsize = 0;
 664         s->sync_packet = -1;
 665         s->inpacket_head = -1;
 666         sk->iso_frame_balance = 0;
 667         ++try;
 668         for (u = 0; u < 2; u++) {
 669                 struct urb *inurb = sk->inurb[u];
 670                 struct urb *outurb = sk->outurb[u];
 671                 playback_prep_freqn(sk, outurb);
 672                 inurb->number_of_packets = outurb->number_of_packets;
 673                 inurb->transfer_buffer_length =
 674                         inurb->number_of_packets *
 675                         inurb->iso_frame_desc[0].length;
 676
 677                 if (u == 0) {
 678                         int now;
 679                         struct usb_device *dev = inurb->dev;
 680                         frame = usb_get_current_frame_number(dev);
 681                         do {
 682                                 now = usb_get_current_frame_number(dev);
 683                                 ++iters;
 684                         } while (now > -1 && now == frame);
 685                 }
 686                 err = usb_submit_urb(inurb, GFP_ATOMIC);
 687                 if (err < 0) {
 688                         snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
 689                                    " returned %i\n", u, err);
 690                         return err;
 691                 }
 692                 err = usb_submit_urb(outurb, GFP_ATOMIC);
 693                 if (err < 0) {
 694                         snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
 695                                    " returned %i\n", u, err);
 696                         return err;
 697                 }
 698
 699                 if (inurb->start_frame != outurb->start_frame) {
 700                         snd_printd(KERN_DEBUG
 701                                    "u[%i] start_frames differ in:%u out:%u\n",
 702                                    u, inurb->start_frame, outurb->start_frame);
 703                         goto check_retry;
 704                 }
 705         }
 706         snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
 707         try = 0;
 708 check_retry:
 709         if (try) {
 710                 usb_stream_stop(sk);
 711                 if (try < 5) {
 712                         msleep(1500);
 713                         snd_printd(KERN_DEBUG "goto dotry;\n");
 714                         goto dotry;
 715                 }
 716                 snd_printk(KERN_WARNING"couldn't start"
 717                            " all urbs on the same start_frame.\n");
 718                 return -EFAULT;
 719         }
 720
 721         sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
 722         sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
 723         sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
 724         sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
 725
 726 /* wait, check */
 727         {
 728                 int wait_ms = 3000;
 729                 while (s->state != usb_stream_ready && wait_ms > 0) {
 730                         snd_printdd(KERN_DEBUG "%i\n", s->state);
 731                         msleep(200);
 732                         wait_ms -= 200;
 733                 }
 734         }
 735
 736         return s->state == usb_stream_ready ? 0 : -EFAULT;
 737 }
 738
 739
 740 /*                             stop                                   */
 741
 742 void usb_stream_stop(struct usb_stream_kernel *sk)
 743 {
 744         int u;
 745         if (!sk->s)
 746                 return;
 747         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 748                 usb_kill_urb(sk->inurb[u]);
 749                 usb_kill_urb(sk->outurb[u]);
 750         }
 751         sk->s->state = usb_stream_stopped;
 752         msleep(400);
 753 }