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 /*                             setup                                  */
  12
  13 static unsigned int usb_stream_next_packet_size(struct usb_stream_kernel *sk)
  14 {
  15         struct usb_stream *s = sk->s;
  16
  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
  29                 if (s->idle_outsize + lb + l > s->period_size)
  30                         goto check;
  31
  32                 sk->out_phase = sk->out_phase_peeked;
  33                 urb->iso_frame_desc[pack].offset = lb;
  34                 urb->iso_frame_desc[pack].length = l;
  35                 lb += l;
  36         }
  37         snd_printdd(KERN_DEBUG "%i\n", lb);
  38
  39 check:
  40         urb->number_of_packets = pack;
  41         urb->transfer_buffer_length = lb;
  42         s->idle_outsize += lb - s->period_size;
  43         snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
  44                     lb, s->period_size);
  45 }
  46
  47 static int init_pipe_urbs(struct usb_stream_kernel *sk,
  48                           unsigned int use_packsize,
  49                           struct urb **urbs, char *transfer,
  50                           struct usb_device *dev, int pipe)
  51 {
  52         int u, p;
  53         int maxpacket = use_packsize ?
  54                 use_packsize : usb_maxpacket(dev, pipe);
  55         int transfer_length = maxpacket * sk->n_o_ps;
  56
  57         for (u = 0; u < USB_STREAM_NURBS;
  58              ++u, transfer += transfer_length) {
  59                 struct urb *urb = urbs[u];
  60                 struct usb_iso_packet_descriptor *desc;
  61
  62                 urb->transfer_buffer = transfer;
  63                 urb->dev = dev;
  64                 urb->pipe = pipe;
  65                 urb->number_of_packets = sk->n_o_ps;
  66                 urb->context = sk;
  67                 urb->interval = 1;
  68                 if (usb_pipeout(pipe))
  69                         continue;
  70                 if (usb_urb_ep_type_check(urb))
  71                         return -EINVAL;
  72
  73                 urb->transfer_buffer_length = transfer_length;
  74                 desc = urb->iso_frame_desc;
  75                 desc->offset = 0;
  76                 desc->length = maxpacket;
  77                 for (p = 1; p < sk->n_o_ps; ++p) {
  78                         desc[p].offset = desc[p - 1].offset + maxpacket;
  79                         desc[p].length = maxpacket;
  80                 }
  81         }
  82
  83         return 0;
  84 }
  85
  86 static int init_urbs(struct usb_stream_kernel *sk, unsigned int use_packsize,
  87                      struct usb_device *dev, int in_pipe, int out_pipe)
  88 {
  89         struct usb_stream       *s = sk->s;
  90         char                    *indata =
  91                 (char *)s + sizeof(*s) + sizeof(struct usb_stream_packet) * s->inpackets;
  92         int                     u;
  93
  94         for (u = 0; u < USB_STREAM_NURBS; ++u) {
  95                 sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
  96                 if (!sk->inurb[u])
  97                         return -ENOMEM;
  98
  99                 sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
 100                 if (!sk->outurb[u])
 101                         return -ENOMEM;
 102         }
 103
 104         if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
 105             init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
 106                            out_pipe))
 107                 return -EINVAL;
 108
 109         return 0;
 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 int get_usb_full_speed_rate(unsigned int 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 int get_usb_high_speed_rate(unsigned int 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 int 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         if (sk->write_page) {
 147                 free_pages_exact(sk->write_page, s->write_size);
 148                 sk->write_page = NULL;
 149         }
 150
 151         free_pages_exact(s, s->read_size);
 152         sk->s = NULL;
 153 }
 154
 155 struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
 156                                   struct usb_device *dev,
 157                                   unsigned int in_endpoint,
 158                                   unsigned int out_endpoint,
 159                                   unsigned int sample_rate,
 160                                   unsigned int use_packsize,
 161                                   unsigned int period_frames,
 162                                   unsigned int frame_size)
 163 {
 164         int packets, max_packsize;
 165         int in_pipe, out_pipe;
 166         int read_size = sizeof(struct usb_stream);
 167         int write_size;
 168         int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
 169
 170         in_pipe = usb_rcvisocpipe(dev, in_endpoint);
 171         out_pipe = usb_sndisocpipe(dev, out_endpoint);
 172
 173         max_packsize = use_packsize ?
 174                 use_packsize : usb_maxpacket(dev, in_pipe);
 175
 176         /*
 177                 t_period = period_frames / sample_rate
 178                 iso_packs = t_period / t_iso_frame
 179                         = (period_frames / sample_rate) * (1 / t_iso_frame)
 180         */
 181
 182         packets = period_frames * usb_frames / sample_rate + 1;
 183
 184         if (dev->speed == USB_SPEED_HIGH)
 185                 packets = (packets + 7) & ~7;
 186
 187         read_size += packets * USB_STREAM_URBDEPTH *
 188                 (max_packsize + sizeof(struct usb_stream_packet));
 189
 190         max_packsize = usb_maxpacket(dev, out_pipe);
 191         write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
 192
 193         if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
 194                 snd_printk(KERN_WARNING "a size exceeds 128*PAGE_SIZE\n");
 195                 goto out;
 196         }
 197
 198         sk->s = alloc_pages_exact(read_size,
 199                                   GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
 200         if (!sk->s) {
 201                 pr_warn("us122l: couldn't allocate read buffer\n");
 202                 goto out;
 203         }
 204         sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
 205
 206         sk->s->read_size = read_size;
 207
 208         sk->s->cfg.sample_rate = sample_rate;
 209         sk->s->cfg.frame_size = frame_size;
 210         sk->n_o_ps = packets;
 211         sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
 212         sk->s->cfg.period_frames = period_frames;
 213         sk->s->period_size = frame_size * period_frames;
 214
 215         sk->s->write_size = write_size;
 216
 217         sk->write_page = alloc_pages_exact(write_size,
 218                                            GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
 219         if (!sk->write_page) {
 220                 pr_warn("us122l: couldn't allocate write buffer\n");
 221                 usb_stream_free(sk);
 222                 return NULL;
 223         }
 224
 225         /* calculate the frequency in 16.16 format */
 226         if (dev->speed == USB_SPEED_FULL)
 227                 sk->freqn = get_usb_full_speed_rate(sample_rate);
 228         else
 229                 sk->freqn = get_usb_high_speed_rate(sample_rate);
 230
 231         if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
 232                 usb_stream_free(sk);
 233                 return NULL;
 234         }
 235
 236         sk->s->state = usb_stream_stopped;
 237 out:
 238         return sk->s;
 239 }
 240
 241 /*                             start                                  */
 242
 243 static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
 244 {
 245         bool r;
 246
 247         if (unlikely(urb->status)) {
 248                 if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
 249                         snd_printk(KERN_WARNING "status=%i\n", urb->status);
 250                 sk->iso_frame_balance = 0x7FFFFFFF;
 251                 return false;
 252         }
 253         r = sk->iso_frame_balance == 0;
 254         if (!r)
 255                 sk->i_urb = urb;
 256         return r;
 257 }
 258
 259 static bool balance_playback(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 bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
 266 {
 267         sk->iso_frame_balance -= urb->number_of_packets;
 268         return balance_check(sk, urb);
 269 }
 270
 271 static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
 272 {
 273         int u;
 274
 275         for (u = 0; u < USB_STREAM_NURBS; u++) {
 276                 struct urb *urb = urbs[u];
 277
 278                 urb->complete = complete;
 279         }
 280 }
 281
 282 static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
 283                 struct urb *inurb)
 284 {
 285         struct usb_stream *s = sk->s;
 286         struct urb *io;
 287         struct usb_iso_packet_descriptor *id, *od;
 288         int p = 0, lb = 0, l = 0;
 289
 290         io = sk->idle_outurb;
 291         od = io->iso_frame_desc;
 292
 293         for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
 294                 struct urb *ii = sk->completed_inurb;
 295
 296                 id = ii->iso_frame_desc +
 297                         ii->number_of_packets + s->sync_packet;
 298                 l = id->actual_length;
 299
 300                 od[p].length = l;
 301                 od[p].offset = lb;
 302                 lb += l;
 303         }
 304
 305         for (;
 306              s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
 307              ++p, ++s->sync_packet) {
 308                 l = inurb->iso_frame_desc[s->sync_packet].actual_length;
 309
 310                 if (s->idle_outsize + lb + l > s->period_size)
 311                         goto check_ok;
 312
 313                 od[p].length = l;
 314                 od[p].offset = lb;
 315                 lb += l;
 316         }
 317
 318 check_ok:
 319         s->sync_packet -= inurb->number_of_packets;
 320         if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
 321                 snd_printk(KERN_WARNING "invalid sync_packet = %i;"
 322                            " p=%i nop=%i %i %x %x %x > %x\n",
 323                            s->sync_packet, p, inurb->number_of_packets,
 324                            s->idle_outsize + lb + l,
 325                            s->idle_outsize, lb,  l,
 326                            s->period_size);
 327                 return -1;
 328         }
 329         if (unlikely(lb % s->cfg.frame_size)) {
 330                 snd_printk(KERN_WARNING"invalid outsize = %i\n",
 331                            lb);
 332                 return -1;
 333         }
 334         s->idle_outsize += lb - s->period_size;
 335         io->number_of_packets = p;
 336         io->transfer_buffer_length = lb;
 337         if (s->idle_outsize <= 0)
 338                 return 0;
 339
 340         snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
 341         return -1;
 342 }
 343
 344 static void prepare_inurb(int number_of_packets, struct urb *iu)
 345 {
 346         struct usb_iso_packet_descriptor *id;
 347         int p;
 348
 349         iu->number_of_packets = number_of_packets;
 350         id = iu->iso_frame_desc;
 351         id->offset = 0;
 352         for (p = 0; p < iu->number_of_packets - 1; ++p)
 353                 id[p + 1].offset = id[p].offset + id[p].length;
 354
 355         iu->transfer_buffer_length =
 356                 id[0].length * iu->number_of_packets;
 357 }
 358
 359 static int submit_urbs(struct usb_stream_kernel *sk,
 360                        struct urb *inurb, struct urb *outurb)
 361 {
 362         int err;
 363
 364         prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
 365         err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
 366         if (err < 0)
 367                 goto report_failure;
 368
 369         sk->idle_inurb = sk->completed_inurb;
 370         sk->completed_inurb = inurb;
 371         err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
 372         if (err < 0)
 373                 goto report_failure;
 374
 375         sk->idle_outurb = sk->completed_outurb;
 376         sk->completed_outurb = outurb;
 377         return 0;
 378
 379 report_failure:
 380         snd_printk(KERN_ERR "%i\n", err);
 381         return err;
 382 }
 383
 384 #ifdef DEBUG_LOOP_BACK
 385 /*
 386   This loop_back() shows how to read/write the period data.
 387  */
 388 static void loop_back(struct usb_stream *s)
 389 {
 390         char *i, *o;
 391         int il, ol, l, p;
 392         struct urb *iu;
 393         struct usb_iso_packet_descriptor *id;
 394
 395         o = s->playback1st_to;
 396         ol = s->playback1st_size;
 397         l = 0;
 398
 399         if (s->insplit_pack >= 0) {
 400                 iu = sk->idle_inurb;
 401                 id = iu->iso_frame_desc;
 402                 p = s->insplit_pack;
 403         } else
 404                 goto second;
 405 loop:
 406         for (; p < iu->number_of_packets && l < s->period_size; ++p) {
 407                 i = iu->transfer_buffer + id[p].offset;
 408                 il = id[p].actual_length;
 409                 if (l + il > s->period_size)
 410                         il = s->period_size - l;
 411                 if (il <= ol) {
 412                         memcpy(o, i, il);
 413                         o += il;
 414                         ol -= il;
 415                 } else {
 416                         memcpy(o, i, ol);
 417                         singen_6pack(o, ol);
 418                         o = s->playback_to;
 419                         memcpy(o, i + ol, il - ol);
 420                         o += il - ol;
 421                         ol = s->period_size - s->playback1st_size;
 422                 }
 423                 l += il;
 424         }
 425         if (iu == sk->completed_inurb) {
 426                 if (l != s->period_size)
 427                         printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
 428                                l/(int)s->cfg.frame_size);
 429
 430                 return;
 431         }
 432 second:
 433         iu = sk->completed_inurb;
 434         id = iu->iso_frame_desc;
 435         p = 0;
 436         goto loop;
 437
 438 }
 439 #else
 440 static void loop_back(struct usb_stream *s)
 441 {
 442 }
 443 #endif
 444
 445 static void stream_idle(struct usb_stream_kernel *sk,
 446                         struct urb *inurb, struct urb *outurb)
 447 {
 448         struct usb_stream *s = sk->s;
 449         int l, p;
 450         int insize = s->idle_insize;
 451         int urb_size = 0;
 452
 453         s->inpacket_split = s->next_inpacket_split;
 454         s->inpacket_split_at = s->next_inpacket_split_at;
 455         s->next_inpacket_split = -1;
 456         s->next_inpacket_split_at = 0;
 457
 458         for (p = 0; p < inurb->number_of_packets; ++p) {
 459                 struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
 460
 461                 l = id[p].actual_length;
 462                 if (unlikely(l == 0 || id[p].status)) {
 463                         snd_printk(KERN_WARNING "underrun, status=%u\n",
 464                                    id[p].status);
 465                         goto err_out;
 466                 }
 467                 s->inpacket_head++;
 468                 s->inpacket_head %= s->inpackets;
 469                 if (s->inpacket_split == -1)
 470                         s->inpacket_split = s->inpacket_head;
 471
 472                 s->inpacket[s->inpacket_head].offset =
 473                         id[p].offset + (inurb->transfer_buffer - (void *)s);
 474                 s->inpacket[s->inpacket_head].length = l;
 475                 if (insize + l > s->period_size &&
 476                     s->next_inpacket_split == -1) {
 477                         s->next_inpacket_split = s->inpacket_head;
 478                         s->next_inpacket_split_at = s->period_size - insize;
 479                 }
 480                 insize += l;
 481                 urb_size += l;
 482         }
 483         s->idle_insize += urb_size - s->period_size;
 484         if (s->idle_insize < 0) {
 485                 snd_printk(KERN_WARNING "%i\n",
 486                            (s->idle_insize)/(int)s->cfg.frame_size);
 487                 goto err_out;
 488         }
 489         s->insize_done += urb_size;
 490
 491         l = s->idle_outsize;
 492         s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
 493                                   sk->write_page) - l;
 494
 495         if (usb_stream_prepare_playback(sk, inurb) < 0)
 496                 goto err_out;
 497
 498         s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
 499         s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
 500                 sk->write_page;
 501
 502         if (submit_urbs(sk, inurb, outurb) < 0)
 503                 goto err_out;
 504
 505         loop_back(s);
 506         s->periods_done++;
 507         wake_up_all(&sk->sleep);
 508         return;
 509 err_out:
 510         s->state = usb_stream_xrun;
 511         wake_up_all(&sk->sleep);
 512 }
 513
 514 static void i_capture_idle(struct urb *urb)
 515 {
 516         struct usb_stream_kernel *sk = urb->context;
 517
 518         if (balance_capture(sk, urb))
 519                 stream_idle(sk, urb, sk->i_urb);
 520 }
 521
 522 static void i_playback_idle(struct urb *urb)
 523 {
 524         struct usb_stream_kernel *sk = urb->context;
 525
 526         if (balance_playback(sk, urb))
 527                 stream_idle(sk, sk->i_urb, urb);
 528 }
 529
 530 static void stream_start(struct usb_stream_kernel *sk,
 531                          struct urb *inurb, struct urb *outurb)
 532 {
 533         struct usb_stream *s = sk->s;
 534
 535         if (s->state >= usb_stream_sync1) {
 536                 int l, p, max_diff, max_diff_0;
 537                 int urb_size = 0;
 538                 unsigned int frames_per_packet, min_frames = 0;
 539
 540                 frames_per_packet = (s->period_size - s->idle_insize);
 541                 frames_per_packet <<= 8;
 542                 frames_per_packet /=
 543                         s->cfg.frame_size * inurb->number_of_packets;
 544                 frames_per_packet++;
 545
 546                 max_diff_0 = s->cfg.frame_size;
 547                 if (s->cfg.period_frames >= 256)
 548                         max_diff_0 <<= 1;
 549                 if (s->cfg.period_frames >= 1024)
 550                         max_diff_0 <<= 1;
 551                 max_diff = max_diff_0;
 552                 for (p = 0; p < inurb->number_of_packets; ++p) {
 553                         int diff;
 554
 555                         l = inurb->iso_frame_desc[p].actual_length;
 556                         urb_size += l;
 557
 558                         min_frames += frames_per_packet;
 559                         diff = urb_size -
 560                                 (min_frames >> 8) * s->cfg.frame_size;
 561                         if (diff < max_diff) {
 562                                 snd_printdd(KERN_DEBUG "%i %i %i %i\n",
 563                                             s->insize_done,
 564                                             urb_size / (int)s->cfg.frame_size,
 565                                             inurb->number_of_packets, diff);
 566                                 max_diff = diff;
 567                         }
 568                 }
 569                 s->idle_insize -= max_diff - max_diff_0;
 570                 s->idle_insize += urb_size - s->period_size;
 571                 if (s->idle_insize < 0) {
 572                         snd_printk(KERN_WARNING "%i %i %i\n",
 573                                    s->idle_insize, urb_size, s->period_size);
 574                         return;
 575                 } else if (s->idle_insize == 0) {
 576                         s->next_inpacket_split =
 577                                 (s->inpacket_head + 1) % s->inpackets;
 578                         s->next_inpacket_split_at = 0;
 579                 } else {
 580                         unsigned int split = s->inpacket_head;
 581
 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
 630                 if (l < s->cfg.frame_size) {
 631                         ++empty;
 632                         if (s->state >= usb_stream_sync0) {
 633                                 snd_printk(KERN_WARNING "%i\n", l);
 634                                 return;
 635                         }
 636                 }
 637                 s->inpacket_head++;
 638                 s->inpacket_head %= s->inpackets;
 639                 s->inpacket[s->inpacket_head].offset =
 640                         id[p].offset + (urb->transfer_buffer - (void *)s);
 641                 s->inpacket[s->inpacket_head].length = l;
 642         }
 643 #ifdef SHOW_EMPTY
 644         if (empty) {
 645                 printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
 646                        urb->iso_frame_desc[0].actual_length);
 647                 for (pack = 1; pack < urb->number_of_packets; ++pack) {
 648                         int l = urb->iso_frame_desc[pack].actual_length;
 649
 650                         printk(KERN_CONT " %i", l);
 651                 }
 652                 printk(KERN_CONT "\n");
 653         }
 654 #endif
 655         if (!empty && s->state < usb_stream_sync1)
 656                 ++s->state;
 657
 658         if (balance_capture(sk, urb))
 659                 stream_start(sk, urb, sk->i_urb);
 660 }
 661
 662 static void i_playback_start(struct urb *urb)
 663 {
 664         struct usb_stream_kernel *sk = urb->context;
 665
 666         if (balance_playback(sk, urb))
 667                 stream_start(sk, sk->i_urb, urb);
 668 }
 669
 670 int usb_stream_start(struct usb_stream_kernel *sk)
 671 {
 672         struct usb_stream *s = sk->s;
 673         int frame = 0, iters = 0;
 674         int u, err;
 675         int try = 0;
 676
 677         if (s->state != usb_stream_stopped)
 678                 return -EAGAIN;
 679
 680         subs_set_complete(sk->inurb, i_capture_start);
 681         subs_set_complete(sk->outurb, i_playback_start);
 682         memset(sk->write_page, 0, s->write_size);
 683 dotry:
 684         s->insize_done = 0;
 685         s->idle_insize = 0;
 686         s->idle_outsize = 0;
 687         s->sync_packet = -1;
 688         s->inpacket_head = -1;
 689         sk->iso_frame_balance = 0;
 690         ++try;
 691         for (u = 0; u < 2; u++) {
 692                 struct urb *inurb = sk->inurb[u];
 693                 struct urb *outurb = sk->outurb[u];
 694
 695                 playback_prep_freqn(sk, outurb);
 696                 inurb->number_of_packets = outurb->number_of_packets;
 697                 inurb->transfer_buffer_length =
 698                         inurb->number_of_packets *
 699                         inurb->iso_frame_desc[0].length;
 700
 701                 if (u == 0) {
 702                         int now;
 703                         struct usb_device *dev = inurb->dev;
 704
 705                         frame = usb_get_current_frame_number(dev);
 706                         do {
 707                                 now = usb_get_current_frame_number(dev);
 708                                 ++iters;
 709                         } while (now > -1 && now == frame);
 710                 }
 711                 err = usb_submit_urb(inurb, GFP_ATOMIC);
 712                 if (err < 0) {
 713                         snd_printk(KERN_ERR
 714                                    "usb_submit_urb(sk->inurb[%i]) returned %i\n",
 715                                    u, err);
 716                         return err;
 717                 }
 718                 err = usb_submit_urb(outurb, GFP_ATOMIC);
 719                 if (err < 0) {
 720                         snd_printk(KERN_ERR
 721                                    "usb_submit_urb(sk->outurb[%i]) returned %i\n",
 722                                    u, err);
 723                         return err;
 724                 }
 725
 726                 if (inurb->start_frame != outurb->start_frame) {
 727                         snd_printd(KERN_DEBUG
 728                                    "u[%i] start_frames differ in:%u out:%u\n",
 729                                    u, inurb->start_frame, outurb->start_frame);
 730                         goto check_retry;
 731                 }
 732         }
 733         snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
 734         try = 0;
 735 check_retry:
 736         if (try) {
 737                 usb_stream_stop(sk);
 738                 if (try < 5) {
 739                         msleep(1500);
 740                         snd_printd(KERN_DEBUG "goto dotry;\n");
 741                         goto dotry;
 742                 }
 743                 snd_printk(KERN_WARNING
 744                            "couldn't start all urbs on the same start_frame.\n");
 745                 return -EFAULT;
 746         }
 747
 748         sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
 749         sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
 750         sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
 751         sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
 752
 753 /* wait, check */
 754         {
 755                 int wait_ms = 3000;
 756
 757                 while (s->state != usb_stream_ready && wait_ms > 0) {
 758                         snd_printdd(KERN_DEBUG "%i\n", s->state);
 759                         msleep(200);
 760                         wait_ms -= 200;
 761                 }
 762         }
 763
 764         return s->state == usb_stream_ready ? 0 : -EFAULT;
 765 }
 766
 767
 768 /*                             stop                                   */
 769
 770 void usb_stream_stop(struct usb_stream_kernel *sk)
 771 {
 772         int u;
 773
 774         if (!sk->s)
 775                 return;
 776         for (u = 0; u < USB_STREAM_NURBS; ++u) {
 777                 usb_kill_urb(sk->inurb[u]);
 778                 usb_kill_urb(sk->outurb[u]);
 779         }
 780         sk->s->state = usb_stream_stopped;
 781         msleep(400);
 782 }