sound/usb/line6/pcm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Line 6 Linux USB driver
   4  *
   5  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   6  */
   7
   8 #include <linux/slab.h>
   9 #include <linux/export.h>
  10 #include <sound/core.h>
  11 #include <sound/control.h>
  12 #include <sound/pcm.h>
  13 #include <sound/pcm_params.h>
  14
  15 #include "capture.h"
  16 #include "driver.h"
  17 #include "playback.h"
  18
  19 /* impulse response volume controls */
  20 static int snd_line6_impulse_volume_info(struct snd_kcontrol *kcontrol,
  21                                          struct snd_ctl_elem_info *uinfo)
  22 {
  23         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
  24         uinfo->count = 1;
  25         uinfo->value.integer.min = 0;
  26         uinfo->value.integer.max = 255;
  27         return 0;
  28 }
  29
  30 static int snd_line6_impulse_volume_get(struct snd_kcontrol *kcontrol,
  31                                         struct snd_ctl_elem_value *ucontrol)
  32 {
  33         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  34
  35         ucontrol->value.integer.value[0] = line6pcm->impulse_volume;
  36         return 0;
  37 }
  38
  39 static int snd_line6_impulse_volume_put(struct snd_kcontrol *kcontrol,
  40                                         struct snd_ctl_elem_value *ucontrol)
  41 {
  42         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  43         int value = ucontrol->value.integer.value[0];
  44         int err;
  45
  46         if (line6pcm->impulse_volume == value)
  47                 return 0;
  48
  49         line6pcm->impulse_volume = value;
  50         if (value > 0) {
  51                 err = line6_pcm_acquire(line6pcm, LINE6_STREAM_IMPULSE, true);
  52                 if (err < 0) {
  53                         line6pcm->impulse_volume = 0;
  54                         return err;
  55                 }
  56         } else {
  57                 line6_pcm_release(line6pcm, LINE6_STREAM_IMPULSE);
  58         }
  59         return 1;
  60 }
  61
  62 /* impulse response period controls */
  63 static int snd_line6_impulse_period_info(struct snd_kcontrol *kcontrol,
  64                                          struct snd_ctl_elem_info *uinfo)
  65 {
  66         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
  67         uinfo->count = 1;
  68         uinfo->value.integer.min = 0;
  69         uinfo->value.integer.max = 2000;
  70         return 0;
  71 }
  72
  73 static int snd_line6_impulse_period_get(struct snd_kcontrol *kcontrol,
  74                                         struct snd_ctl_elem_value *ucontrol)
  75 {
  76         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  77
  78         ucontrol->value.integer.value[0] = line6pcm->impulse_period;
  79         return 0;
  80 }
  81
  82 static int snd_line6_impulse_period_put(struct snd_kcontrol *kcontrol,
  83                                         struct snd_ctl_elem_value *ucontrol)
  84 {
  85         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
  86         int value = ucontrol->value.integer.value[0];
  87
  88         if (line6pcm->impulse_period == value)
  89                 return 0;
  90
  91         line6pcm->impulse_period = value;
  92         return 1;
  93 }
  94
  95 /*
  96         Unlink all currently active URBs.
  97 */
  98 static void line6_unlink_audio_urbs(struct snd_line6_pcm *line6pcm,
  99                                     struct line6_pcm_stream *pcms)
 100 {
 101         int i;
 102
 103         for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
 104                 if (test_bit(i, &pcms->active_urbs)) {
 105                         if (!test_and_set_bit(i, &pcms->unlink_urbs))
 106                                 usb_unlink_urb(pcms->urbs[i]);
 107                 }
 108         }
 109 }
 110
 111 /*
 112         Wait until unlinking of all currently active URBs has been finished.
 113 */
 114 static void line6_wait_clear_audio_urbs(struct snd_line6_pcm *line6pcm,
 115                                         struct line6_pcm_stream *pcms)
 116 {
 117         int timeout = HZ;
 118         int i;
 119         int alive;
 120
 121         do {
 122                 alive = 0;
 123                 for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
 124                         if (test_bit(i, &pcms->active_urbs))
 125                                 alive++;
 126                 }
 127                 if (!alive)
 128                         break;
 129                 set_current_state(TASK_UNINTERRUPTIBLE);
 130                 schedule_timeout(1);
 131         } while (--timeout > 0);
 132         if (alive)
 133                 dev_err(line6pcm->line6->ifcdev,
 134                         "timeout: still %d active urbs..\n", alive);
 135 }
 136
 137 static inline struct line6_pcm_stream *
 138 get_stream(struct snd_line6_pcm *line6pcm, int direction)
 139 {
 140         return (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
 141                 &line6pcm->out : &line6pcm->in;
 142 }
 143
 144 /* allocate a buffer if not opened yet;
 145  * call this in line6pcm.state_mutex
 146  */
 147 static int line6_buffer_acquire(struct snd_line6_pcm *line6pcm,
 148                                 struct line6_pcm_stream *pstr, int direction, int type)
 149 {
 150         const int pkt_size =
 151                 (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
 152                         line6pcm->max_packet_size_out :
 153                         line6pcm->max_packet_size_in;
 154
 155         /* Invoked multiple times in a row so allocate once only */
 156         if (!test_and_set_bit(type, &pstr->opened) && !pstr->buffer) {
 157                 pstr->buffer =
 158                         kmalloc(array3_size(line6pcm->line6->iso_buffers,
 159                                             LINE6_ISO_PACKETS, pkt_size),
 160                                 GFP_KERNEL);
 161                 if (!pstr->buffer)
 162                         return -ENOMEM;
 163         }
 164         return 0;
 165 }
 166
 167 /* free a buffer if all streams are closed;
 168  * call this in line6pcm.state_mutex
 169  */
 170 static void line6_buffer_release(struct snd_line6_pcm *line6pcm,
 171                                  struct line6_pcm_stream *pstr, int type)
 172 {
 173         clear_bit(type, &pstr->opened);
 174         if (!pstr->opened) {
 175                 line6_wait_clear_audio_urbs(line6pcm, pstr);
 176                 kfree(pstr->buffer);
 177                 pstr->buffer = NULL;
 178         }
 179 }
 180
 181 /* start a PCM stream */
 182 static int line6_stream_start(struct snd_line6_pcm *line6pcm, int direction,
 183                               int type)
 184 {
 185         unsigned long flags;
 186         struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
 187         int ret = 0;
 188
 189         spin_lock_irqsave(&pstr->lock, flags);
 190         if (!test_and_set_bit(type, &pstr->running) &&
 191             !(pstr->active_urbs || pstr->unlink_urbs)) {
 192                 pstr->count = 0;
 193                 /* Submit all currently available URBs */
 194                 if (direction == SNDRV_PCM_STREAM_PLAYBACK)
 195                         ret = line6_submit_audio_out_all_urbs(line6pcm);
 196                 else
 197                         ret = line6_submit_audio_in_all_urbs(line6pcm);
 198         }
 199
 200         if (ret < 0)
 201                 clear_bit(type, &pstr->running);
 202         spin_unlock_irqrestore(&pstr->lock, flags);
 203         return ret;
 204 }
 205
 206 /* stop a PCM stream; this doesn't sync with the unlinked URBs */
 207 static void line6_stream_stop(struct snd_line6_pcm *line6pcm, int direction,
 208                           int type)
 209 {
 210         unsigned long flags;
 211         struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
 212
 213         spin_lock_irqsave(&pstr->lock, flags);
 214         clear_bit(type, &pstr->running);
 215         if (!pstr->running) {
 216                 spin_unlock_irqrestore(&pstr->lock, flags);
 217                 line6_unlink_audio_urbs(line6pcm, pstr);
 218                 spin_lock_irqsave(&pstr->lock, flags);
 219                 if (direction == SNDRV_PCM_STREAM_CAPTURE) {
 220                         line6pcm->prev_fbuf = NULL;
 221                         line6pcm->prev_fsize = 0;
 222                 }
 223         }
 224         spin_unlock_irqrestore(&pstr->lock, flags);
 225 }
 226
 227 /* common PCM trigger callback */
 228 int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
 229 {
 230         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 231         struct snd_pcm_substream *s;
 232         int err;
 233
 234         clear_bit(LINE6_FLAG_PREPARED, &line6pcm->flags);
 235
 236         snd_pcm_group_for_each_entry(s, substream) {
 237                 if (s->pcm->card != substream->pcm->card)
 238                         continue;
 239
 240                 switch (cmd) {
 241                 case SNDRV_PCM_TRIGGER_START:
 242                 case SNDRV_PCM_TRIGGER_RESUME:
 243                         if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
 244                                 (line6pcm->line6->properties->capabilities &
 245                                         LINE6_CAP_IN_NEEDS_OUT)) {
 246                                 err = line6_stream_start(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
 247                                                  LINE6_STREAM_CAPTURE_HELPER);
 248                                 if (err < 0)
 249                                         return err;
 250                         }
 251                         err = line6_stream_start(line6pcm, s->stream,
 252                                                  LINE6_STREAM_PCM);
 253                         if (err < 0)
 254                                 return err;
 255                         break;
 256
 257                 case SNDRV_PCM_TRIGGER_STOP:
 258                 case SNDRV_PCM_TRIGGER_SUSPEND:
 259                         if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
 260                                 (line6pcm->line6->properties->capabilities &
 261                                         LINE6_CAP_IN_NEEDS_OUT)) {
 262                                 line6_stream_stop(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
 263                                           LINE6_STREAM_CAPTURE_HELPER);
 264                         }
 265                         line6_stream_stop(line6pcm, s->stream,
 266                                           LINE6_STREAM_PCM);
 267                         break;
 268
 269                 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 270                         if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
 271                                 return -EINVAL;
 272                         set_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
 273                         break;
 274
 275                 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 276                         if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
 277                                 return -EINVAL;
 278                         clear_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
 279                         break;
 280
 281                 default:
 282                         return -EINVAL;
 283                 }
 284         }
 285
 286         return 0;
 287 }
 288
 289 /* common PCM pointer callback */
 290 snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream)
 291 {
 292         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 293         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 294
 295         return pstr->pos_done;
 296 }
 297
 298 /* Acquire and optionally start duplex streams:
 299  * type is either LINE6_STREAM_IMPULSE or LINE6_STREAM_MONITOR
 300  */
 301 int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type, bool start)
 302 {
 303         struct line6_pcm_stream *pstr;
 304         int ret = 0, dir;
 305
 306         /* TODO: We should assert SNDRV_PCM_STREAM_PLAYBACK/CAPTURE == 0/1 */
 307         mutex_lock(&line6pcm->state_mutex);
 308         for (dir = 0; dir < 2; dir++) {
 309                 pstr = get_stream(line6pcm, dir);
 310                 ret = line6_buffer_acquire(line6pcm, pstr, dir, type);
 311                 if (ret < 0)
 312                         goto error;
 313                 if (!pstr->running)
 314                         line6_wait_clear_audio_urbs(line6pcm, pstr);
 315         }
 316         if (start) {
 317                 for (dir = 0; dir < 2; dir++) {
 318                         ret = line6_stream_start(line6pcm, dir, type);
 319                         if (ret < 0)
 320                                 goto error;
 321                 }
 322         }
 323  error:
 324         mutex_unlock(&line6pcm->state_mutex);
 325         if (ret < 0)
 326                 line6_pcm_release(line6pcm, type);
 327         return ret;
 328 }
 329 EXPORT_SYMBOL_GPL(line6_pcm_acquire);
 330
 331 /* Stop and release duplex streams */
 332 void line6_pcm_release(struct snd_line6_pcm *line6pcm, int type)
 333 {
 334         struct line6_pcm_stream *pstr;
 335         int dir;
 336
 337         mutex_lock(&line6pcm->state_mutex);
 338         for (dir = 0; dir < 2; dir++)
 339                 line6_stream_stop(line6pcm, dir, type);
 340         for (dir = 0; dir < 2; dir++) {
 341                 pstr = get_stream(line6pcm, dir);
 342                 line6_buffer_release(line6pcm, pstr, type);
 343         }
 344         mutex_unlock(&line6pcm->state_mutex);
 345 }
 346 EXPORT_SYMBOL_GPL(line6_pcm_release);
 347
 348 /* common PCM hw_params callback */
 349 int snd_line6_hw_params(struct snd_pcm_substream *substream,
 350                         struct snd_pcm_hw_params *hw_params)
 351 {
 352         int ret;
 353         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 354         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 355
 356         mutex_lock(&line6pcm->state_mutex);
 357         ret = line6_buffer_acquire(line6pcm, pstr, substream->stream,
 358                                    LINE6_STREAM_PCM);
 359         if (ret < 0)
 360                 goto error;
 361
 362         ret = snd_pcm_lib_malloc_pages(substream,
 363                                        params_buffer_bytes(hw_params));
 364         if (ret < 0) {
 365                 line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
 366                 goto error;
 367         }
 368
 369         pstr->period = params_period_bytes(hw_params);
 370  error:
 371         mutex_unlock(&line6pcm->state_mutex);
 372         return ret;
 373 }
 374
 375 /* common PCM hw_free callback */
 376 int snd_line6_hw_free(struct snd_pcm_substream *substream)
 377 {
 378         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 379         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 380
 381         mutex_lock(&line6pcm->state_mutex);
 382         line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
 383         mutex_unlock(&line6pcm->state_mutex);
 384         return snd_pcm_lib_free_pages(substream);
 385 }
 386
 387
 388 /* control info callback */
 389 static int snd_line6_control_playback_info(struct snd_kcontrol *kcontrol,
 390                                            struct snd_ctl_elem_info *uinfo)
 391 {
 392         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 393         uinfo->count = 2;
 394         uinfo->value.integer.min = 0;
 395         uinfo->value.integer.max = 256;
 396         return 0;
 397 }
 398
 399 /* control get callback */
 400 static int snd_line6_control_playback_get(struct snd_kcontrol *kcontrol,
 401                                           struct snd_ctl_elem_value *ucontrol)
 402 {
 403         int i;
 404         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 405
 406         for (i = 0; i < 2; i++)
 407                 ucontrol->value.integer.value[i] = line6pcm->volume_playback[i];
 408
 409         return 0;
 410 }
 411
 412 /* control put callback */
 413 static int snd_line6_control_playback_put(struct snd_kcontrol *kcontrol,
 414                                           struct snd_ctl_elem_value *ucontrol)
 415 {
 416         int i, changed = 0;
 417         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 418
 419         for (i = 0; i < 2; i++)
 420                 if (line6pcm->volume_playback[i] !=
 421                     ucontrol->value.integer.value[i]) {
 422                         line6pcm->volume_playback[i] =
 423                             ucontrol->value.integer.value[i];
 424                         changed = 1;
 425                 }
 426
 427         return changed;
 428 }
 429
 430 /* control definition */
 431 static const struct snd_kcontrol_new line6_controls[] = {
 432         {
 433                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 434                 .name = "PCM Playback Volume",
 435                 .info = snd_line6_control_playback_info,
 436                 .get = snd_line6_control_playback_get,
 437                 .put = snd_line6_control_playback_put
 438         },
 439         {
 440                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 441                 .name = "Impulse Response Volume",
 442                 .info = snd_line6_impulse_volume_info,
 443                 .get = snd_line6_impulse_volume_get,
 444                 .put = snd_line6_impulse_volume_put
 445         },
 446         {
 447                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 448                 .name = "Impulse Response Period",
 449                 .info = snd_line6_impulse_period_info,
 450                 .get = snd_line6_impulse_period_get,
 451                 .put = snd_line6_impulse_period_put
 452         },
 453 };
 454
 455 /*
 456         Cleanup the PCM device.
 457 */
 458 static void cleanup_urbs(struct line6_pcm_stream *pcms, int iso_buffers)
 459 {
 460         int i;
 461
 462         /* Most likely impossible in current code... */
 463         if (pcms->urbs == NULL)
 464                 return;
 465
 466         for (i = 0; i < iso_buffers; i++) {
 467                 if (pcms->urbs[i]) {
 468                         usb_kill_urb(pcms->urbs[i]);
 469                         usb_free_urb(pcms->urbs[i]);
 470                 }
 471         }
 472         kfree(pcms->urbs);
 473         pcms->urbs = NULL;
 474 }
 475
 476 static void line6_cleanup_pcm(struct snd_pcm *pcm)
 477 {
 478         struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);
 479
 480         cleanup_urbs(&line6pcm->out, line6pcm->line6->iso_buffers);
 481         cleanup_urbs(&line6pcm->in, line6pcm->line6->iso_buffers);
 482         kfree(line6pcm);
 483 }
 484
 485 /* create a PCM device */
 486 static int snd_line6_new_pcm(struct usb_line6 *line6, struct snd_pcm **pcm_ret)
 487 {
 488         struct snd_pcm *pcm;
 489         int err;
 490
 491         err = snd_pcm_new(line6->card, (char *)line6->properties->name,
 492                           0, 1, 1, pcm_ret);
 493         if (err < 0)
 494                 return err;
 495         pcm = *pcm_ret;
 496         strcpy(pcm->name, line6->properties->name);
 497
 498         /* set operators */
 499         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 500                         &snd_line6_playback_ops);
 501         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_line6_capture_ops);
 502
 503         /* pre-allocation of buffers */
 504         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 505                                               snd_dma_continuous_data
 506                                               (GFP_KERNEL), 64 * 1024,
 507                                               128 * 1024);
 508         return 0;
 509 }
 510
 511 /*
 512         Sync with PCM stream stops.
 513 */
 514 void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm)
 515 {
 516         line6_unlink_audio_urbs(line6pcm, &line6pcm->out);
 517         line6_unlink_audio_urbs(line6pcm, &line6pcm->in);
 518         line6_wait_clear_audio_urbs(line6pcm, &line6pcm->out);
 519         line6_wait_clear_audio_urbs(line6pcm, &line6pcm->in);
 520 }
 521
 522 /*
 523         Create and register the PCM device and mixer entries.
 524         Create URBs for playback and capture.
 525 */
 526 int line6_init_pcm(struct usb_line6 *line6,
 527                    struct line6_pcm_properties *properties)
 528 {
 529         int i, err;
 530         unsigned ep_read = line6->properties->ep_audio_r;
 531         unsigned ep_write = line6->properties->ep_audio_w;
 532         struct snd_pcm *pcm;
 533         struct snd_line6_pcm *line6pcm;
 534
 535         if (!(line6->properties->capabilities & LINE6_CAP_PCM))
 536                 return 0;       /* skip PCM initialization and report success */
 537
 538         err = snd_line6_new_pcm(line6, &pcm);
 539         if (err < 0)
 540                 return err;
 541
 542         line6pcm = kzalloc(sizeof(*line6pcm), GFP_KERNEL);
 543         if (!line6pcm)
 544                 return -ENOMEM;
 545
 546         mutex_init(&line6pcm->state_mutex);
 547         line6pcm->pcm = pcm;
 548         line6pcm->properties = properties;
 549         line6pcm->volume_playback[0] = line6pcm->volume_playback[1] = 255;
 550         line6pcm->volume_monitor = 255;
 551         line6pcm->line6 = line6;
 552
 553         spin_lock_init(&line6pcm->out.lock);
 554         spin_lock_init(&line6pcm->in.lock);
 555         line6pcm->impulse_period = LINE6_IMPULSE_DEFAULT_PERIOD;
 556
 557         line6->line6pcm = line6pcm;
 558
 559         pcm->private_data = line6pcm;
 560         pcm->private_free = line6_cleanup_pcm;
 561
 562         line6pcm->max_packet_size_in =
 563                 usb_maxpacket(line6->usbdev,
 564                         usb_rcvisocpipe(line6->usbdev, ep_read), 0);
 565         line6pcm->max_packet_size_out =
 566                 usb_maxpacket(line6->usbdev,
 567                         usb_sndisocpipe(line6->usbdev, ep_write), 1);
 568         if (!line6pcm->max_packet_size_in || !line6pcm->max_packet_size_out) {
 569                 dev_err(line6pcm->line6->ifcdev,
 570                         "cannot get proper max packet size\n");
 571                 return -EINVAL;
 572         }
 573
 574         err = line6_create_audio_out_urbs(line6pcm);
 575         if (err < 0)
 576                 return err;
 577
 578         err = line6_create_audio_in_urbs(line6pcm);
 579         if (err < 0)
 580                 return err;
 581
 582         /* mixer: */
 583         for (i = 0; i < ARRAY_SIZE(line6_controls); i++) {
 584                 err = snd_ctl_add(line6->card,
 585                                   snd_ctl_new1(&line6_controls[i], line6pcm));
 586                 if (err < 0)
 587                         return err;
 588         }
 589
 590         return 0;
 591 }
 592 EXPORT_SYMBOL_GPL(line6_init_pcm);
 593
 594 /* prepare pcm callback */
 595 int snd_line6_prepare(struct snd_pcm_substream *substream)
 596 {
 597         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 598         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 599
 600         mutex_lock(&line6pcm->state_mutex);
 601         if (!pstr->running)
 602                 line6_wait_clear_audio_urbs(line6pcm, pstr);
 603
 604         if (!test_and_set_bit(LINE6_FLAG_PREPARED, &line6pcm->flags)) {
 605                 line6pcm->out.count = 0;
 606                 line6pcm->out.pos = 0;
 607                 line6pcm->out.pos_done = 0;
 608                 line6pcm->out.bytes = 0;
 609                 line6pcm->in.count = 0;
 610                 line6pcm->in.pos_done = 0;
 611                 line6pcm->in.bytes = 0;
 612         }
 613
 614         mutex_unlock(&line6pcm->state_mutex);
 615         return 0;
 616 }