sound/usb/usx2y/usb_stream.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
   4  */
   5
   6 #include <linux/usb.h>
   7 #include <linux/gfp.h>
   8
   9 #include "usb_stream.h"
  10
  11
  12 /*                             setup                                  */
  13
  14 static unsigned usb_stream_next_packet_size(struct usb_stream_kernel *sk)
  15 {
  16         struct usb_stream *s = sk->s;
  17         sk->out_phase_peeked = (sk->out_phase & 0xffff) + sk->freqn;
  18         return (sk->out_phase_peeked >> 16) * s->cfg.frame_size;
  19 }
  20
  21 static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb)
  22 {
  23         struct usb_stream *s = sk->s;
  24         int pack, lb = 0;
  25
  26         for (pack = 0; pack < sk->n_o_ps; pack++) {
  27                 int l = usb_stream_next_packet_size(sk);
  28                 if (s->idle_outsize + lb + l > s->period_size)
  29                         goto check;
  30
  31                 sk->out_phase = sk->out_phase_peeked;
  32                 urb->iso_frame_desc[pack].offset = lb;
  33                 urb->iso_frame_desc[pack].length = l;
  34                 lb += l;
  35         }
  36         snd_printdd(KERN_DEBUG "%i\n", lb);
  37
  38 check:
  39         urb->number_of_packets = pack;
  40         urb->transfer_buffer_length = lb;
  41         s->idle_outsize += lb - s->period_size;
  42         snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
  43                     lb, s->period_size);
  44 }
  45
  46 static int init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
  47                            struct urb **urbs, char *transfer,
  48                            struct usb_device *dev, int pipe)
  49 {
  50         int u, p;
  51         int maxpacket = use_packsize ?
  52                 use_packsize : usb_maxpacket(dev, pipe, usb_pipeout(pipe));
  53         int transfer_length = maxpacket * sk->n_o_ps;
  54
  55         for (u = 0; u < USB_STREAM_NURBS;
  56              ++u, transfer += transfer_length) {
  57                 struct urb *urb = urbs[u];
  58                 struct usb_iso_packet_descriptor *desc;
  59                 urb->transfer_buffer = transfer;
  60                 urb->dev = dev;
  61                 urb->pipe = pipe;
  62                 urb->number_of_packets = sk->n_o_ps;
  63                 urb->context = sk;
  64                 urb->interval = 1;
  65                 if (usb_pipeout(pipe))
  66                         continue;
  67                 if (usb_urb_ep_type_check(urb))
  68                         return -EINVAL;
  69
  70                 urb->transfer_buffer_length = transfer_length;
  71                 desc = urb->iso_frame_desc;
  72                 desc->offset = 0;
  73                 desc->length = maxpacket;
  74                 for (p = 1; p < sk->n_o_ps; ++p) {
  75                         desc[p].offset = desc[p - 1].offset + maxpacket;
  76                         desc[p].length = maxpacket;
  77                 }
  78         }
  79
  80         return 0;
  81 }
  82
  83 static int init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
  84                       struct usb_device *dev, int in_pipe, int out_pipe)
  85 {
  86         struct usb_stream       *s = sk->s;
  87         char                    *indata = (char *)s + sizeof(*s) +
  88                                         sizeof(struct usb_stream_packet) *
  89                                         s->inpackets;
  90         int                     u;
  91
  92         for (u = 0; u < USB_STREAM_NURBS; ++u) {
  93                 sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
  94                 if (!sk->inurb[u])
  95                         return -ENOMEM;
  96
  97                 sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
  98                 if (!sk->outurb[u])
  99                         return -ENOMEM;
 100         }
 101
 102         if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
 103             init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
 104                            out_pipe))
 105                 return -EINVAL;
 106
 107         return 0;
 108 }
 109
 110
 111 /*
 112  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
 113  * this will overflow at approx 524 kHz
 114  */
 115 static inline unsigned get_usb_full_speed_rate(unsigned rate)
 116 {
 117         return ((rate << 13) + 62) / 125;
 118 }
 119
 120 /*
 121  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
 122  * this will overflow at approx 4 MHz
 123  */
 124 static inline unsigned get_usb_high_speed_rate(unsigned rate)
 125 {
 126         return ((rate << 10) + 62) / 125;
 127 }
 128
 129 void usb_stream_free(struct usb_stream_kernel *sk)
 130 {
 131         struct usb_stream *s;
 132         unsigned u;
 133
 134         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 135                 usb_free_urb(sk->inurb[u]);
 136                 sk->inurb[u] = NULL;
 137                 usb_free_urb(sk->outurb[u]);
 138                 sk->outurb[u] = NULL;
 139         }
 140
 141         s = sk->s;
 142         if (!s)
 143                 return;
 144
 145         if (sk->write_page) {
 146                 free_pages_exact(sk->write_page, s->write_size);
 147                 sk->write_page = NULL;
 148         }
 149
 150         free_pages_exact(s, s->read_size);
 151         sk->s = NULL;
 152 }
 153
 154 struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
 155                                   struct usb_device *dev,
 156                                   unsigned in_endpoint, unsigned out_endpoint,
 157                                   unsigned sample_rate, unsigned use_packsize,
 158                                   unsigned period_frames, unsigned frame_size)
 159 {
 160         int packets, max_packsize;
 161         int in_pipe, out_pipe;
 162         int read_size = sizeof(struct usb_stream);
 163         int write_size;
 164         int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
 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         sk->s = alloc_pages_exact(read_size,
 195                                   GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
 196         if (!sk->s) {
 197                 pr_warn("us122l: couldn't allocate read buffer\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
 213         sk->write_page = alloc_pages_exact(write_size,
 214                                            GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
 215         if (!sk->write_page) {
 216                 pr_warn("us122l: couldn't allocate write buffer\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         if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
 228                 usb_stream_free(sk);
 229                 return NULL;
 230         }
 231
 232         sk->s->state = usb_stream_stopped;
 233 out:
 234         return sk->s;
 235 }
 236
 237
 238 /*                             start                                  */
 239
 240 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
 241 {
 242         bool r;
 243         if (unlikely(urb->status)) {
 244                 if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
 245                         snd_printk(KERN_WARNING "status=%i\n", urb->status);
 246                 sk->iso_frame_balance = 0x7FFFFFFF;
 247                 return false;
 248         }
 249         r = sk->iso_frame_balance == 0;
 250         if (!r)
 251                 sk->i_urb = urb;
 252         return r;
 253 }
 254
 255 static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
 256 {
 257         sk->iso_frame_balance += urb->number_of_packets;
 258         return balance_check(sk, urb);
 259 }
 260
 261 static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
 262 {
 263         sk->iso_frame_balance -= urb->number_of_packets;
 264         return balance_check(sk, urb);
 265 }
 266
 267 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
 268 {
 269         int u;
 270
 271         for (u = 0; u < USB_STREAM_NURBS; u++) {
 272                 struct urb *urb = urbs[u];
 273                 urb->complete = complete;
 274         }
 275 }
 276
 277 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
 278                 struct urb *inurb)
 279 {
 280         struct usb_stream *s = sk->s;
 281         struct urb *io;
 282         struct usb_iso_packet_descriptor *id, *od;
 283         int p = 0, lb = 0, l = 0;
 284
 285         io = sk->idle_outurb;
 286         od = io->iso_frame_desc;
 287
 288         for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
 289                 struct urb *ii = sk->completed_inurb;
 290                 id = ii->iso_frame_desc +
 291                         ii->number_of_packets + s->sync_packet;
 292                 l = id->actual_length;
 293
 294                 od[p].length = l;
 295                 od[p].offset = lb;
 296                 lb += l;
 297         }
 298
 299         for (;
 300              s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
 301              ++p, ++s->sync_packet) {
 302                 l = inurb->iso_frame_desc[s->sync_packet].actual_length;
 303
 304                 if (s->idle_outsize + lb + l > s->period_size)
 305                         goto check_ok;
 306
 307                 od[p].length = l;
 308                 od[p].offset = lb;
 309                 lb += l;
 310         }
 311
 312 check_ok:
 313         s->sync_packet -= inurb->number_of_packets;
 314         if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
 315                 snd_printk(KERN_WARNING "invalid sync_packet = %i;"
 316                            " p=%i nop=%i %i %x %x %x > %x\n",
 317                            s->sync_packet, p, inurb->number_of_packets,
 318                            s->idle_outsize + lb + l,
 319                            s->idle_outsize, lb,  l,
 320                            s->period_size);
 321                 return -1;
 322         }
 323         if (unlikely(lb % s->cfg.frame_size)) {
 324                 snd_printk(KERN_WARNING"invalid outsize = %i\n",
 325                            lb);
 326                 return -1;
 327         }
 328         s->idle_outsize += lb - s->period_size;
 329         io->number_of_packets = p;
 330         io->transfer_buffer_length = lb;
 331         if (s->idle_outsize <= 0)
 332                 return 0;
 333
 334         snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
 335         return -1;
 336 }
 337
 338 static void prepare_inurb(int number_of_packets, struct urb *iu)
 339 {
 340         struct usb_iso_packet_descriptor *id;
 341         int p;
 342
 343         iu->number_of_packets = number_of_packets;
 344         id = iu->iso_frame_desc;
 345         id->offset = 0;
 346         for (p = 0; p < iu->number_of_packets - 1; ++p)
 347                 id[p + 1].offset = id[p].offset + id[p].length;
 348
 349         iu->transfer_buffer_length =
 350                 id[0].length * iu->number_of_packets;
 351 }
 352
 353 static int submit_urbs(struct usb_stream_kernel *sk,
 354                        struct urb *inurb, struct urb *outurb)
 355 {
 356         int err;
 357         prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
 358         err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
 359         if (err < 0)
 360                 goto report_failure;
 361
 362         sk->idle_inurb = sk->completed_inurb;
 363         sk->completed_inurb = inurb;
 364         err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
 365         if (err < 0)
 366                 goto report_failure;
 367
 368         sk->idle_outurb = sk->completed_outurb;
 369         sk->completed_outurb = outurb;
 370         return 0;
 371
 372 report_failure:
 373         snd_printk(KERN_ERR "%i\n", err);
 374         return err;
 375 }
 376
 377 #ifdef DEBUG_LOOP_BACK
 378 /*
 379   This loop_back() shows how to read/write the period data.
 380  */
 381 static void loop_back(struct usb_stream *s)
 382 {
 383         char *i, *o;
 384         int il, ol, l, p;
 385         struct urb *iu;
 386         struct usb_iso_packet_descriptor *id;
 387
 388         o = s->playback1st_to;
 389         ol = s->playback1st_size;
 390         l = 0;
 391
 392         if (s->insplit_pack >= 0) {
 393                 iu = sk->idle_inurb;
 394                 id = iu->iso_frame_desc;
 395                 p = s->insplit_pack;
 396         } else
 397                 goto second;
 398 loop:
 399         for (; p < iu->number_of_packets && l < s->period_size; ++p) {
 400                 i = iu->transfer_buffer + id[p].offset;
 401                 il = id[p].actual_length;
 402                 if (l + il > s->period_size)
 403                         il = s->period_size - l;
 404                 if (il <= ol) {
 405                         memcpy(o, i, il);
 406                         o += il;
 407                         ol -= il;
 408                 } else {
 409                         memcpy(o, i, ol);
 410                         singen_6pack(o, ol);
 411                         o = s->playback_to;
 412                         memcpy(o, i + ol, il - ol);
 413                         o += il - ol;
 414                         ol = s->period_size - s->playback1st_size;
 415                 }
 416                 l += il;
 417         }
 418         if (iu == sk->completed_inurb) {
 419                 if (l != s->period_size)
 420                         printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
 421                                l/(int)s->cfg.frame_size);
 422
 423                 return;
 424         }
 425 second:
 426         iu = sk->completed_inurb;
 427         id = iu->iso_frame_desc;
 428         p = 0;
 429         goto loop;
 430
 431 }
 432 #else
 433 static void loop_back(struct usb_stream *s)
 434 {
 435 }
 436 #endif
 437
 438 static void stream_idle(struct usb_stream_kernel *sk,
 439                         struct urb *inurb, struct urb *outurb)
 440 {
 441         struct usb_stream *s = sk->s;
 442         int l, p;
 443         int insize = s->idle_insize;
 444         int urb_size = 0;
 445
 446         s->inpacket_split = s->next_inpacket_split;
 447         s->inpacket_split_at = s->next_inpacket_split_at;
 448         s->next_inpacket_split = -1;
 449         s->next_inpacket_split_at = 0;
 450
 451         for (p = 0; p < inurb->number_of_packets; ++p) {
 452                 struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
 453                 l = id[p].actual_length;
 454                 if (unlikely(l == 0 || id[p].status)) {
 455                         snd_printk(KERN_WARNING "underrun, status=%u\n",
 456                                    id[p].status);
 457                         goto err_out;
 458                 }
 459                 s->inpacket_head++;
 460                 s->inpacket_head %= s->inpackets;
 461                 if (s->inpacket_split == -1)
 462                         s->inpacket_split = s->inpacket_head;
 463
 464                 s->inpacket[s->inpacket_head].offset =
 465                         id[p].offset + (inurb->transfer_buffer - (void *)s);
 466                 s->inpacket[s->inpacket_head].length = l;
 467                 if (insize + l > s->period_size &&
 468                     s->next_inpacket_split == -1) {
 469                         s->next_inpacket_split = s->inpacket_head;
 470                         s->next_inpacket_split_at = s->period_size - insize;
 471                 }
 472                 insize += l;
 473                 urb_size += l;
 474         }
 475         s->idle_insize += urb_size - s->period_size;
 476         if (s->idle_insize < 0) {
 477                 snd_printk(KERN_WARNING "%i\n",
 478                            (s->idle_insize)/(int)s->cfg.frame_size);
 479                 goto err_out;
 480         }
 481         s->insize_done += urb_size;
 482
 483         l = s->idle_outsize;
 484         s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
 485                                   sk->write_page) - l;
 486
 487         if (usb_stream_prepare_playback(sk, inurb) < 0)
 488                 goto err_out;
 489
 490         s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
 491         s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
 492                 sk->write_page;
 493
 494         if (submit_urbs(sk, inurb, outurb) < 0)
 495                 goto err_out;
 496
 497         loop_back(s);
 498         s->periods_done++;
 499         wake_up_all(&sk->sleep);
 500         return;
 501 err_out:
 502         s->state = usb_stream_xrun;
 503         wake_up_all(&sk->sleep);
 504 }
 505
 506 static void i_capture_idle(struct urb *urb)
 507 {
 508         struct usb_stream_kernel *sk = urb->context;
 509         if (balance_capture(sk, urb))
 510                 stream_idle(sk, urb, sk->i_urb);
 511 }
 512
 513 static void i_playback_idle(struct urb *urb)
 514 {
 515         struct usb_stream_kernel *sk = urb->context;
 516         if (balance_playback(sk, urb))
 517                 stream_idle(sk, sk->i_urb, urb);
 518 }
 519
 520 static void stream_start(struct usb_stream_kernel *sk,
 521                          struct urb *inurb, struct urb *outurb)
 522 {
 523         struct usb_stream *s = sk->s;
 524         if (s->state >= usb_stream_sync1) {
 525                 int l, p, max_diff, max_diff_0;
 526                 int urb_size = 0;
 527                 unsigned frames_per_packet, min_frames = 0;
 528                 frames_per_packet = (s->period_size - s->idle_insize);
 529                 frames_per_packet <<= 8;
 530                 frames_per_packet /=
 531                         s->cfg.frame_size * inurb->number_of_packets;
 532                 frames_per_packet++;
 533
 534                 max_diff_0 = s->cfg.frame_size;
 535                 if (s->cfg.period_frames >= 256)
 536                         max_diff_0 <<= 1;
 537                 if (s->cfg.period_frames >= 1024)
 538                         max_diff_0 <<= 1;
 539                 max_diff = max_diff_0;
 540                 for (p = 0; p < inurb->number_of_packets; ++p) {
 541                         int diff;
 542                         l = inurb->iso_frame_desc[p].actual_length;
 543                         urb_size += l;
 544
 545                         min_frames += frames_per_packet;
 546                         diff = urb_size -
 547                                 (min_frames >> 8) * s->cfg.frame_size;
 548                         if (diff < max_diff) {
 549                                 snd_printdd(KERN_DEBUG "%i %i %i %i\n",
 550                                             s->insize_done,
 551                                             urb_size / (int)s->cfg.frame_size,
 552                                             inurb->number_of_packets, diff);
 553                                 max_diff = diff;
 554                         }
 555                 }
 556                 s->idle_insize -= max_diff - max_diff_0;
 557                 s->idle_insize += urb_size - s->period_size;
 558                 if (s->idle_insize < 0) {
 559                         snd_printk(KERN_WARNING "%i %i %i\n",
 560                                    s->idle_insize, urb_size, s->period_size);
 561                         return;
 562                 } else if (s->idle_insize == 0) {
 563                         s->next_inpacket_split =
 564                                 (s->inpacket_head + 1) % s->inpackets;
 565                         s->next_inpacket_split_at = 0;
 566                 } else {
 567                         unsigned split = s->inpacket_head;
 568                         l = s->idle_insize;
 569                         while (l > s->inpacket[split].length) {
 570                                 l -= s->inpacket[split].length;
 571                                 if (split == 0)
 572                                         split = s->inpackets - 1;
 573                                 else
 574                                         split--;
 575                         }
 576                         s->next_inpacket_split = split;
 577                         s->next_inpacket_split_at =
 578                                 s->inpacket[split].length - l;
 579                 }
 580
 581                 s->insize_done += urb_size;
 582
 583                 if (usb_stream_prepare_playback(sk, inurb) < 0)
 584                         return;
 585
 586         } else
 587                 playback_prep_freqn(sk, sk->idle_outurb);
 588
 589         if (submit_urbs(sk, inurb, outurb) < 0)
 590                 return;
 591
 592         if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
 593                 /* just guesswork                            ^^^^^^ */
 594                 s->state = usb_stream_ready;
 595                 subs_set_complete(sk->inurb, i_capture_idle);
 596                 subs_set_complete(sk->outurb, i_playback_idle);
 597         }
 598 }
 599
 600 static void i_capture_start(struct urb *urb)
 601 {
 602         struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
 603         struct usb_stream_kernel *sk = urb->context;
 604         struct usb_stream *s = sk->s;
 605         int p;
 606         int empty = 0;
 607
 608         if (urb->status) {
 609                 snd_printk(KERN_WARNING "status=%i\n", urb->status);
 610                 return;
 611         }
 612
 613         for (p = 0; p < urb->number_of_packets; ++p) {
 614                 int l = id[p].actual_length;
 615                 if (l < s->cfg.frame_size) {
 616                         ++empty;
 617                         if (s->state >= usb_stream_sync0) {
 618                                 snd_printk(KERN_WARNING "%i\n", l);
 619                                 return;
 620                         }
 621                 }
 622                 s->inpacket_head++;
 623                 s->inpacket_head %= s->inpackets;
 624                 s->inpacket[s->inpacket_head].offset =
 625                         id[p].offset + (urb->transfer_buffer - (void *)s);
 626                 s->inpacket[s->inpacket_head].length = l;
 627         }
 628 #ifdef SHOW_EMPTY
 629         if (empty) {
 630                 printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
 631                        urb->iso_frame_desc[0].actual_length);
 632                 for (pack = 1; pack < urb->number_of_packets; ++pack) {
 633                         int l = urb->iso_frame_desc[pack].actual_length;
 634                         printk(KERN_CONT " %i", l);
 635                 }
 636                 printk(KERN_CONT "\n");
 637         }
 638 #endif
 639         if (!empty && s->state < usb_stream_sync1)
 640                 ++s->state;
 641
 642         if (balance_capture(sk, urb))
 643                 stream_start(sk, urb, sk->i_urb);
 644 }
 645
 646 static void i_playback_start(struct urb *urb)
 647 {
 648         struct usb_stream_kernel *sk = urb->context;
 649         if (balance_playback(sk, urb))
 650                 stream_start(sk, sk->i_urb, urb);
 651 }
 652
 653 int usb_stream_start(struct usb_stream_kernel *sk)
 654 {
 655         struct usb_stream *s = sk->s;
 656         int frame = 0, iters = 0;
 657         int u, err;
 658         int try = 0;
 659
 660         if (s->state != usb_stream_stopped)
 661                 return -EAGAIN;
 662
 663         subs_set_complete(sk->inurb, i_capture_start);
 664         subs_set_complete(sk->outurb, i_playback_start);
 665         memset(sk->write_page, 0, s->write_size);
 666 dotry:
 667         s->insize_done = 0;
 668         s->idle_insize = 0;
 669         s->idle_outsize = 0;
 670         s->sync_packet = -1;
 671         s->inpacket_head = -1;
 672         sk->iso_frame_balance = 0;
 673         ++try;
 674         for (u = 0; u < 2; u++) {
 675                 struct urb *inurb = sk->inurb[u];
 676                 struct urb *outurb = sk->outurb[u];
 677                 playback_prep_freqn(sk, outurb);
 678                 inurb->number_of_packets = outurb->number_of_packets;
 679                 inurb->transfer_buffer_length =
 680                         inurb->number_of_packets *
 681                         inurb->iso_frame_desc[0].length;
 682
 683                 if (u == 0) {
 684                         int now;
 685                         struct usb_device *dev = inurb->dev;
 686                         frame = usb_get_current_frame_number(dev);
 687                         do {
 688                                 now = usb_get_current_frame_number(dev);
 689                                 ++iters;
 690                         } while (now > -1 && now == frame);
 691                 }
 692                 err = usb_submit_urb(inurb, GFP_ATOMIC);
 693                 if (err < 0) {
 694                         snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
 695                                    " returned %i\n", u, err);
 696                         return err;
 697                 }
 698                 err = usb_submit_urb(outurb, GFP_ATOMIC);
 699                 if (err < 0) {
 700                         snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
 701                                    " returned %i\n", u, err);
 702                         return err;
 703                 }
 704
 705                 if (inurb->start_frame != outurb->start_frame) {
 706                         snd_printd(KERN_DEBUG
 707                                    "u[%i] start_frames differ in:%u out:%u\n",
 708                                    u, inurb->start_frame, outurb->start_frame);
 709                         goto check_retry;
 710                 }
 711         }
 712         snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
 713         try = 0;
 714 check_retry:
 715         if (try) {
 716                 usb_stream_stop(sk);
 717                 if (try < 5) {
 718                         msleep(1500);
 719                         snd_printd(KERN_DEBUG "goto dotry;\n");
 720                         goto dotry;
 721                 }
 722                 snd_printk(KERN_WARNING"couldn't start"
 723                            " all urbs on the same start_frame.\n");
 724                 return -EFAULT;
 725         }
 726
 727         sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
 728         sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
 729         sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
 730         sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
 731
 732 /* wait, check */
 733         {
 734                 int wait_ms = 3000;
 735                 while (s->state != usb_stream_ready && wait_ms > 0) {
 736                         snd_printdd(KERN_DEBUG "%i\n", s->state);
 737                         msleep(200);
 738                         wait_ms -= 200;
 739                 }
 740         }
 741
 742         return s->state == usb_stream_ready ? 0 : -EFAULT;
 743 }
 744
 745
 746 /*                             stop                                   */
 747
 748 void usb_stream_stop(struct usb_stream_kernel *sk)
 749 {
 750         int u;
 751         if (!sk->s)
 752                 return;
 753         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 754                 usb_kill_urb(sk->inurb[u]);
 755                 usb_kill_urb(sk->outurb[u]);
 756         }
 757         sk->s->state = usb_stream_stopped;
 758         msleep(400);
 759 }