sound/usb/line6/pcm.c

   1 /*
   2  * Line 6 Linux USB driver
   3  *
   4  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/export.h>
  14 #include <sound/core.h>
  15 #include <sound/control.h>
  16 #include <sound/pcm.h>
  17 #include <sound/pcm_params.h>
  18
  19 #include "capture.h"
  20 #include "driver.h"
  21 #include "playback.h"
  22
  23 /* impulse response volume controls */
  24 static int snd_line6_impulse_volume_info(struct snd_kcontrol *kcontrol,
  25                                          struct snd_ctl_elem_info *uinfo)
  26 {
  27         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
  28         uinfo->count = 1;
  29         uinfo->value.integer.min = 0;
  30         uinfo->value.integer.max = 255;
  31         return 0;
  32 }
  33
  34 static int snd_line6_impulse_volume_get(struct snd_kcontrol *kcontrol,
  35                                         struct snd_ctl_elem_value *ucontrol)
  36 {
  37         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  38
  39         ucontrol->value.integer.value[0] = line6pcm->impulse_volume;
  40         return 0;
  41 }
  42
  43 static int snd_line6_impulse_volume_put(struct snd_kcontrol *kcontrol,
  44                                         struct snd_ctl_elem_value *ucontrol)
  45 {
  46         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  47         int value = ucontrol->value.integer.value[0];
  48         int err;
  49
  50         if (line6pcm->impulse_volume == value)
  51                 return 0;
  52
  53         line6pcm->impulse_volume = value;
  54         if (value > 0) {
  55                 err = line6_pcm_acquire(line6pcm, LINE6_STREAM_IMPULSE, true);
  56                 if (err < 0) {
  57                         line6pcm->impulse_volume = 0;
  58                         return err;
  59                 }
  60         } else {
  61                 line6_pcm_release(line6pcm, LINE6_STREAM_IMPULSE);
  62         }
  63         return 1;
  64 }
  65
  66 /* impulse response period controls */
  67 static int snd_line6_impulse_period_info(struct snd_kcontrol *kcontrol,
  68                                          struct snd_ctl_elem_info *uinfo)
  69 {
  70         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
  71         uinfo->count = 1;
  72         uinfo->value.integer.min = 0;
  73         uinfo->value.integer.max = 2000;
  74         return 0;
  75 }
  76
  77 static int snd_line6_impulse_period_get(struct snd_kcontrol *kcontrol,
  78                                         struct snd_ctl_elem_value *ucontrol)
  79 {
  80         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  81
  82         ucontrol->value.integer.value[0] = line6pcm->impulse_period;
  83         return 0;
  84 }
  85
  86 static int snd_line6_impulse_period_put(struct snd_kcontrol *kcontrol,
  87                                         struct snd_ctl_elem_value *ucontrol)
  88 {
  89         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  90         int value = ucontrol->value.integer.value[0];
  91
  92         if (line6pcm->impulse_period == value)
  93                 return 0;
  94
  95         line6pcm->impulse_period = value;
  96         return 1;
  97 }
  98
  99 /*
 100         Unlink all currently active URBs.
 101 */
 102 static void line6_unlink_audio_urbs(struct snd_line6_pcm *line6pcm,
 103                                     struct line6_pcm_stream *pcms)
 104 {
 105         int i;
 106
 107         for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
 108                 if (test_bit(i, &pcms->active_urbs)) {
 109                         if (!test_and_set_bit(i, &pcms->unlink_urbs))
 110                                 usb_unlink_urb(pcms->urbs[i]);
 111                 }
 112         }
 113 }
 114
 115 /*
 116         Wait until unlinking of all currently active URBs has been finished.
 117 */
 118 static void line6_wait_clear_audio_urbs(struct snd_line6_pcm *line6pcm,
 119                                         struct line6_pcm_stream *pcms)
 120 {
 121         int timeout = HZ;
 122         int i;
 123         int alive;
 124
 125         do {
 126                 alive = 0;
 127                 for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
 128                         if (test_bit(i, &pcms->active_urbs))
 129                                 alive++;
 130                 }
 131                 if (!alive)
 132                         break;
 133                 set_current_state(TASK_UNINTERRUPTIBLE);
 134                 schedule_timeout(1);
 135         } while (--timeout > 0);
 136         if (alive)
 137                 dev_err(line6pcm->line6->ifcdev,
 138                         "timeout: still %d active urbs..\n", alive);
 139 }
 140
 141 static inline struct line6_pcm_stream *
 142 get_stream(struct snd_line6_pcm *line6pcm, int direction)
 143 {
 144         return (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
 145                 &line6pcm->out : &line6pcm->in;
 146 }
 147
 148 /* allocate a buffer if not opened yet;
 149  * call this in line6pcm.state_mutex
 150  */
 151 static int line6_buffer_acquire(struct snd_line6_pcm *line6pcm,
 152                                 struct line6_pcm_stream *pstr, int direction, int type)
 153 {
 154         const int pkt_size =
 155                 (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
 156                         line6pcm->max_packet_size_out :
 157                         line6pcm->max_packet_size_in;
 158
 159         /* Invoked multiple times in a row so allocate once only */
 160         if (!test_and_set_bit(type, &pstr->opened) && !pstr->buffer) {
 161                 pstr->buffer = kmalloc(line6pcm->line6->iso_buffers *
 162                                        LINE6_ISO_PACKETS * pkt_size, GFP_KERNEL);
 163                 if (!pstr->buffer)
 164                         return -ENOMEM;
 165         }
 166         return 0;
 167 }
 168
 169 /* free a buffer if all streams are closed;
 170  * call this in line6pcm.state_mutex
 171  */
 172 static void line6_buffer_release(struct snd_line6_pcm *line6pcm,
 173                                  struct line6_pcm_stream *pstr, int type)
 174 {
 175         clear_bit(type, &pstr->opened);
 176         if (!pstr->opened) {
 177                 line6_wait_clear_audio_urbs(line6pcm, pstr);
 178                 kfree(pstr->buffer);
 179                 pstr->buffer = NULL;
 180         }
 181 }
 182
 183 /* start a PCM stream */
 184 static int line6_stream_start(struct snd_line6_pcm *line6pcm, int direction,
 185                               int type)
 186 {
 187         unsigned long flags;
 188         struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
 189         int ret = 0;
 190
 191         spin_lock_irqsave(&pstr->lock, flags);
 192         if (!test_and_set_bit(type, &pstr->running) &&
 193             !(pstr->active_urbs || pstr->unlink_urbs)) {
 194                 pstr->count = 0;
 195                 /* Submit all currently available URBs */
 196                 if (direction == SNDRV_PCM_STREAM_PLAYBACK)
 197                         ret = line6_submit_audio_out_all_urbs(line6pcm);
 198                 else
 199                         ret = line6_submit_audio_in_all_urbs(line6pcm);
 200         }
 201
 202         if (ret < 0)
 203                 clear_bit(type, &pstr->running);
 204         spin_unlock_irqrestore(&pstr->lock, flags);
 205         return ret;
 206 }
 207
 208 /* stop a PCM stream; this doesn't sync with the unlinked URBs */
 209 static void line6_stream_stop(struct snd_line6_pcm *line6pcm, int direction,
 210                           int type)
 211 {
 212         unsigned long flags;
 213         struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
 214
 215         spin_lock_irqsave(&pstr->lock, flags);
 216         clear_bit(type, &pstr->running);
 217         if (!pstr->running) {
 218                 spin_unlock_irqrestore(&pstr->lock, flags);
 219                 line6_unlink_audio_urbs(line6pcm, pstr);
 220                 spin_lock_irqsave(&pstr->lock, flags);
 221                 if (direction == SNDRV_PCM_STREAM_CAPTURE) {
 222                         line6pcm->prev_fbuf = NULL;
 223                         line6pcm->prev_fsize = 0;
 224                 }
 225         }
 226         spin_unlock_irqrestore(&pstr->lock, flags);
 227 }
 228
 229 /* common PCM trigger callback */
 230 int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
 231 {
 232         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 233         struct snd_pcm_substream *s;
 234         int err;
 235
 236         clear_bit(LINE6_FLAG_PREPARED, &line6pcm->flags);
 237
 238         snd_pcm_group_for_each_entry(s, substream) {
 239                 if (s->pcm->card != substream->pcm->card)
 240                         continue;
 241
 242                 switch (cmd) {
 243                 case SNDRV_PCM_TRIGGER_START:
 244                 case SNDRV_PCM_TRIGGER_RESUME:
 245                         if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
 246                                 (line6pcm->line6->properties->capabilities &
 247                                         LINE6_CAP_IN_NEEDS_OUT)) {
 248                                 err = line6_stream_start(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
 249                                                  LINE6_STREAM_CAPTURE_HELPER);
 250                                 if (err < 0)
 251                                         return err;
 252                         }
 253                         err = line6_stream_start(line6pcm, s->stream,
 254                                                  LINE6_STREAM_PCM);
 255                         if (err < 0)
 256                                 return err;
 257                         break;
 258
 259                 case SNDRV_PCM_TRIGGER_STOP:
 260                 case SNDRV_PCM_TRIGGER_SUSPEND:
 261                         if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
 262                                 (line6pcm->line6->properties->capabilities &
 263                                         LINE6_CAP_IN_NEEDS_OUT)) {
 264                                 line6_stream_stop(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
 265                                           LINE6_STREAM_CAPTURE_HELPER);
 266                         }
 267                         line6_stream_stop(line6pcm, s->stream,
 268                                           LINE6_STREAM_PCM);
 269                         break;
 270
 271                 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 272                         if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
 273                                 return -EINVAL;
 274                         set_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
 275                         break;
 276
 277                 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 278                         if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
 279                                 return -EINVAL;
 280                         clear_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
 281                         break;
 282
 283                 default:
 284                         return -EINVAL;
 285                 }
 286         }
 287
 288         return 0;
 289 }
 290
 291 /* common PCM pointer callback */
 292 snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream)
 293 {
 294         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 295         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 296
 297         return pstr->pos_done;
 298 }
 299
 300 /* Acquire and optionally start duplex streams:
 301  * type is either LINE6_STREAM_IMPULSE or LINE6_STREAM_MONITOR
 302  */
 303 int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type, bool start)
 304 {
 305         struct line6_pcm_stream *pstr;
 306         int ret = 0, dir;
 307
 308         /* TODO: We should assert SNDRV_PCM_STREAM_PLAYBACK/CAPTURE == 0/1 */
 309         mutex_lock(&line6pcm->state_mutex);
 310         for (dir = 0; dir < 2; dir++) {
 311                 pstr = get_stream(line6pcm, dir);
 312                 ret = line6_buffer_acquire(line6pcm, pstr, dir, type);
 313                 if (ret < 0)
 314                         goto error;
 315                 if (!pstr->running)
 316                         line6_wait_clear_audio_urbs(line6pcm, pstr);
 317         }
 318         if (start) {
 319                 for (dir = 0; dir < 2; dir++) {
 320                         ret = line6_stream_start(line6pcm, dir, type);
 321                         if (ret < 0)
 322                                 goto error;
 323                 }
 324         }
 325  error:
 326         mutex_unlock(&line6pcm->state_mutex);
 327         if (ret < 0)
 328                 line6_pcm_release(line6pcm, type);
 329         return ret;
 330 }
 331 EXPORT_SYMBOL_GPL(line6_pcm_acquire);
 332
 333 /* Stop and release duplex streams */
 334 void line6_pcm_release(struct snd_line6_pcm *line6pcm, int type)
 335 {
 336         struct line6_pcm_stream *pstr;
 337         int dir;
 338
 339         mutex_lock(&line6pcm->state_mutex);
 340         for (dir = 0; dir < 2; dir++)
 341                 line6_stream_stop(line6pcm, dir, type);
 342         for (dir = 0; dir < 2; dir++) {
 343                 pstr = get_stream(line6pcm, dir);
 344                 line6_buffer_release(line6pcm, pstr, type);
 345         }
 346         mutex_unlock(&line6pcm->state_mutex);
 347 }
 348 EXPORT_SYMBOL_GPL(line6_pcm_release);
 349
 350 /* common PCM hw_params callback */
 351 int snd_line6_hw_params(struct snd_pcm_substream *substream,
 352                         struct snd_pcm_hw_params *hw_params)
 353 {
 354         int ret;
 355         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 356         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 357
 358         mutex_lock(&line6pcm->state_mutex);
 359         ret = line6_buffer_acquire(line6pcm, pstr, substream->stream,
 360                                    LINE6_STREAM_PCM);
 361         if (ret < 0)
 362                 goto error;
 363
 364         ret = snd_pcm_lib_malloc_pages(substream,
 365                                        params_buffer_bytes(hw_params));
 366         if (ret < 0) {
 367                 line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
 368                 goto error;
 369         }
 370
 371         pstr->period = params_period_bytes(hw_params);
 372  error:
 373         mutex_unlock(&line6pcm->state_mutex);
 374         return ret;
 375 }
 376
 377 /* common PCM hw_free callback */
 378 int snd_line6_hw_free(struct snd_pcm_substream *substream)
 379 {
 380         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 381         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 382
 383         mutex_lock(&line6pcm->state_mutex);
 384         line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
 385         mutex_unlock(&line6pcm->state_mutex);
 386         return snd_pcm_lib_free_pages(substream);
 387 }
 388
 389
 390 /* control info callback */
 391 static int snd_line6_control_playback_info(struct snd_kcontrol *kcontrol,
 392                                            struct snd_ctl_elem_info *uinfo)
 393 {
 394         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 395         uinfo->count = 2;
 396         uinfo->value.integer.min = 0;
 397         uinfo->value.integer.max = 256;
 398         return 0;
 399 }
 400
 401 /* control get callback */
 402 static int snd_line6_control_playback_get(struct snd_kcontrol *kcontrol,
 403                                           struct snd_ctl_elem_value *ucontrol)
 404 {
 405         int i;
 406         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 407
 408         for (i = 0; i < 2; i++)
 409                 ucontrol->value.integer.value[i] = line6pcm->volume_playback[i];
 410
 411         return 0;
 412 }
 413
 414 /* control put callback */
 415 static int snd_line6_control_playback_put(struct snd_kcontrol *kcontrol,
 416                                           struct snd_ctl_elem_value *ucontrol)
 417 {
 418         int i, changed = 0;
 419         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 420
 421         for (i = 0; i < 2; i++)
 422                 if (line6pcm->volume_playback[i] !=
 423                     ucontrol->value.integer.value[i]) {
 424                         line6pcm->volume_playback[i] =
 425                             ucontrol->value.integer.value[i];
 426                         changed = 1;
 427                 }
 428
 429         return changed;
 430 }
 431
 432 /* control definition */
 433 static struct snd_kcontrol_new line6_controls[] = {
 434         {
 435                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 436                 .name = "PCM Playback Volume",
 437                 .info = snd_line6_control_playback_info,
 438                 .get = snd_line6_control_playback_get,
 439                 .put = snd_line6_control_playback_put
 440         },
 441         {
 442                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 443                 .name = "Impulse Response Volume",
 444                 .info = snd_line6_impulse_volume_info,
 445                 .get = snd_line6_impulse_volume_get,
 446                 .put = snd_line6_impulse_volume_put
 447         },
 448         {
 449                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 450                 .name = "Impulse Response Period",
 451                 .info = snd_line6_impulse_period_info,
 452                 .get = snd_line6_impulse_period_get,
 453                 .put = snd_line6_impulse_period_put
 454         },
 455 };
 456
 457 /*
 458         Cleanup the PCM device.
 459 */
 460 static void cleanup_urbs(struct line6_pcm_stream *pcms, int iso_buffers)
 461 {
 462         int i;
 463
 464         /* Most likely impossible in current code... */
 465         if (pcms->urbs == NULL)
 466                 return;
 467
 468         for (i = 0; i < iso_buffers; i++) {
 469                 if (pcms->urbs[i]) {
 470                         usb_kill_urb(pcms->urbs[i]);
 471                         usb_free_urb(pcms->urbs[i]);
 472                 }
 473         }
 474         kfree(pcms->urbs);
 475         pcms->urbs = NULL;
 476 }
 477
 478 static void line6_cleanup_pcm(struct snd_pcm *pcm)
 479 {
 480         struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);
 481
 482         cleanup_urbs(&line6pcm->out, line6pcm->line6->iso_buffers);
 483         cleanup_urbs(&line6pcm->in, line6pcm->line6->iso_buffers);
 484         kfree(line6pcm);
 485 }
 486
 487 /* create a PCM device */
 488 static int snd_line6_new_pcm(struct usb_line6 *line6, struct snd_pcm **pcm_ret)
 489 {
 490         struct snd_pcm *pcm;
 491         int err;
 492
 493         err = snd_pcm_new(line6->card, (char *)line6->properties->name,
 494                           0, 1, 1, pcm_ret);
 495         if (err < 0)
 496                 return err;
 497         pcm = *pcm_ret;
 498         strcpy(pcm->name, line6->properties->name);
 499
 500         /* set operators */
 501         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 502                         &snd_line6_playback_ops);
 503         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_line6_capture_ops);
 504
 505         /* pre-allocation of buffers */
 506         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 507                                               snd_dma_continuous_data
 508                                               (GFP_KERNEL), 64 * 1024,
 509                                               128 * 1024);
 510         return 0;
 511 }
 512
 513 /*
 514         Sync with PCM stream stops.
 515 */
 516 void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm)
 517 {
 518         line6_unlink_audio_urbs(line6pcm, &line6pcm->out);
 519         line6_unlink_audio_urbs(line6pcm, &line6pcm->in);
 520         line6_wait_clear_audio_urbs(line6pcm, &line6pcm->out);
 521         line6_wait_clear_audio_urbs(line6pcm, &line6pcm->in);
 522 }
 523
 524 /*
 525         Create and register the PCM device and mixer entries.
 526         Create URBs for playback and capture.
 527 */
 528 int line6_init_pcm(struct usb_line6 *line6,
 529                    struct line6_pcm_properties *properties)
 530 {
 531         int i, err;
 532         unsigned ep_read = line6->properties->ep_audio_r;
 533         unsigned ep_write = line6->properties->ep_audio_w;
 534         struct snd_pcm *pcm;
 535         struct snd_line6_pcm *line6pcm;
 536
 537         if (!(line6->properties->capabilities & LINE6_CAP_PCM))
 538                 return 0;       /* skip PCM initialization and report success */
 539
 540         err = snd_line6_new_pcm(line6, &pcm);
 541         if (err < 0)
 542                 return err;
 543
 544         line6pcm = kzalloc(sizeof(*line6pcm), GFP_KERNEL);
 545         if (!line6pcm)
 546                 return -ENOMEM;
 547
 548         mutex_init(&line6pcm->state_mutex);
 549         line6pcm->pcm = pcm;
 550         line6pcm->properties = properties;
 551         line6pcm->volume_playback[0] = line6pcm->volume_playback[1] = 255;
 552         line6pcm->volume_monitor = 255;
 553         line6pcm->line6 = line6;
 554
 555         line6pcm->max_packet_size_in =
 556                 usb_maxpacket(line6->usbdev,
 557                         usb_rcvisocpipe(line6->usbdev, ep_read), 0);
 558         line6pcm->max_packet_size_out =
 559                 usb_maxpacket(line6->usbdev,
 560                         usb_sndisocpipe(line6->usbdev, ep_write), 1);
 561
 562         spin_lock_init(&line6pcm->out.lock);
 563         spin_lock_init(&line6pcm->in.lock);
 564         line6pcm->impulse_period = LINE6_IMPULSE_DEFAULT_PERIOD;
 565
 566         line6->line6pcm = line6pcm;
 567
 568         pcm->private_data = line6pcm;
 569         pcm->private_free = line6_cleanup_pcm;
 570
 571         err = line6_create_audio_out_urbs(line6pcm);
 572         if (err < 0)
 573                 return err;
 574
 575         err = line6_create_audio_in_urbs(line6pcm);
 576         if (err < 0)
 577                 return err;
 578
 579         /* mixer: */
 580         for (i = 0; i < ARRAY_SIZE(line6_controls); i++) {
 581                 err = snd_ctl_add(line6->card,
 582                                   snd_ctl_new1(&line6_controls[i], line6pcm));
 583                 if (err < 0)
 584                         return err;
 585         }
 586
 587         return 0;
 588 }
 589 EXPORT_SYMBOL_GPL(line6_init_pcm);
 590
 591 /* prepare pcm callback */
 592 int snd_line6_prepare(struct snd_pcm_substream *substream)
 593 {
 594         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 595         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 596
 597         mutex_lock(&line6pcm->state_mutex);
 598         if (!pstr->running)
 599                 line6_wait_clear_audio_urbs(line6pcm, pstr);
 600
 601         if (!test_and_set_bit(LINE6_FLAG_PREPARED, &line6pcm->flags)) {
 602                 line6pcm->out.count = 0;
 603                 line6pcm->out.pos = 0;
 604                 line6pcm->out.pos_done = 0;
 605                 line6pcm->out.bytes = 0;
 606                 line6pcm->in.count = 0;
 607                 line6pcm->in.pos_done = 0;
 608                 line6pcm->in.bytes = 0;
 609         }
 610
 611         mutex_unlock(&line6pcm->state_mutex);
 612         return 0;
 613 }