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 =
 162                         kmalloc(array3_size(line6pcm->line6->iso_buffers,
 163                                             LINE6_ISO_PACKETS, pkt_size),
 164                                 GFP_KERNEL);
 165                 if (!pstr->buffer)
 166                         return -ENOMEM;
 167         }
 168         return 0;
 169 }
 170
 171 /* free a buffer if all streams are closed;
 172  * call this in line6pcm.state_mutex
 173  */
 174 static void line6_buffer_release(struct snd_line6_pcm *line6pcm,
 175                                  struct line6_pcm_stream *pstr, int type)
 176 {
 177         clear_bit(type, &pstr->opened);
 178         if (!pstr->opened) {
 179                 line6_wait_clear_audio_urbs(line6pcm, pstr);
 180                 kfree(pstr->buffer);
 181                 pstr->buffer = NULL;
 182         }
 183 }
 184
 185 /* start a PCM stream */
 186 static int line6_stream_start(struct snd_line6_pcm *line6pcm, int direction,
 187                               int type)
 188 {
 189         unsigned long flags;
 190         struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
 191         int ret = 0;
 192
 193         spin_lock_irqsave(&pstr->lock, flags);
 194         if (!test_and_set_bit(type, &pstr->running) &&
 195             !(pstr->active_urbs || pstr->unlink_urbs)) {
 196                 pstr->count = 0;
 197                 /* Submit all currently available URBs */
 198                 if (direction == SNDRV_PCM_STREAM_PLAYBACK)
 199                         ret = line6_submit_audio_out_all_urbs(line6pcm);
 200                 else
 201                         ret = line6_submit_audio_in_all_urbs(line6pcm);
 202         }
 203
 204         if (ret < 0)
 205                 clear_bit(type, &pstr->running);
 206         spin_unlock_irqrestore(&pstr->lock, flags);
 207         return ret;
 208 }
 209
 210 /* stop a PCM stream; this doesn't sync with the unlinked URBs */
 211 static void line6_stream_stop(struct snd_line6_pcm *line6pcm, int direction,
 212                           int type)
 213 {
 214         unsigned long flags;
 215         struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
 216
 217         spin_lock_irqsave(&pstr->lock, flags);
 218         clear_bit(type, &pstr->running);
 219         if (!pstr->running) {
 220                 spin_unlock_irqrestore(&pstr->lock, flags);
 221                 line6_unlink_audio_urbs(line6pcm, pstr);
 222                 spin_lock_irqsave(&pstr->lock, flags);
 223                 if (direction == SNDRV_PCM_STREAM_CAPTURE) {
 224                         line6pcm->prev_fbuf = NULL;
 225                         line6pcm->prev_fsize = 0;
 226                 }
 227         }
 228         spin_unlock_irqrestore(&pstr->lock, flags);
 229 }
 230
 231 /* common PCM trigger callback */
 232 int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
 233 {
 234         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 235         struct snd_pcm_substream *s;
 236         int err;
 237
 238         clear_bit(LINE6_FLAG_PREPARED, &line6pcm->flags);
 239
 240         snd_pcm_group_for_each_entry(s, substream) {
 241                 if (s->pcm->card != substream->pcm->card)
 242                         continue;
 243
 244                 switch (cmd) {
 245                 case SNDRV_PCM_TRIGGER_START:
 246                 case SNDRV_PCM_TRIGGER_RESUME:
 247                         if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
 248                                 (line6pcm->line6->properties->capabilities &
 249                                         LINE6_CAP_IN_NEEDS_OUT)) {
 250                                 err = line6_stream_start(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
 251                                                  LINE6_STREAM_CAPTURE_HELPER);
 252                                 if (err < 0)
 253                                         return err;
 254                         }
 255                         err = line6_stream_start(line6pcm, s->stream,
 256                                                  LINE6_STREAM_PCM);
 257                         if (err < 0)
 258                                 return err;
 259                         break;
 260
 261                 case SNDRV_PCM_TRIGGER_STOP:
 262                 case SNDRV_PCM_TRIGGER_SUSPEND:
 263                         if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
 264                                 (line6pcm->line6->properties->capabilities &
 265                                         LINE6_CAP_IN_NEEDS_OUT)) {
 266                                 line6_stream_stop(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
 267                                           LINE6_STREAM_CAPTURE_HELPER);
 268                         }
 269                         line6_stream_stop(line6pcm, s->stream,
 270                                           LINE6_STREAM_PCM);
 271                         break;
 272
 273                 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 274                         if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
 275                                 return -EINVAL;
 276                         set_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
 277                         break;
 278
 279                 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 280                         if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
 281                                 return -EINVAL;
 282                         clear_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
 283                         break;
 284
 285                 default:
 286                         return -EINVAL;
 287                 }
 288         }
 289
 290         return 0;
 291 }
 292
 293 /* common PCM pointer callback */
 294 snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream)
 295 {
 296         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 297         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 298
 299         return pstr->pos_done;
 300 }
 301
 302 /* Acquire and optionally start duplex streams:
 303  * type is either LINE6_STREAM_IMPULSE or LINE6_STREAM_MONITOR
 304  */
 305 int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type, bool start)
 306 {
 307         struct line6_pcm_stream *pstr;
 308         int ret = 0, dir;
 309
 310         /* TODO: We should assert SNDRV_PCM_STREAM_PLAYBACK/CAPTURE == 0/1 */
 311         mutex_lock(&line6pcm->state_mutex);
 312         for (dir = 0; dir < 2; dir++) {
 313                 pstr = get_stream(line6pcm, dir);
 314                 ret = line6_buffer_acquire(line6pcm, pstr, dir, type);
 315                 if (ret < 0)
 316                         goto error;
 317                 if (!pstr->running)
 318                         line6_wait_clear_audio_urbs(line6pcm, pstr);
 319         }
 320         if (start) {
 321                 for (dir = 0; dir < 2; dir++) {
 322                         ret = line6_stream_start(line6pcm, dir, type);
 323                         if (ret < 0)
 324                                 goto error;
 325                 }
 326         }
 327  error:
 328         mutex_unlock(&line6pcm->state_mutex);
 329         if (ret < 0)
 330                 line6_pcm_release(line6pcm, type);
 331         return ret;
 332 }
 333 EXPORT_SYMBOL_GPL(line6_pcm_acquire);
 334
 335 /* Stop and release duplex streams */
 336 void line6_pcm_release(struct snd_line6_pcm *line6pcm, int type)
 337 {
 338         struct line6_pcm_stream *pstr;
 339         int dir;
 340
 341         mutex_lock(&line6pcm->state_mutex);
 342         for (dir = 0; dir < 2; dir++)
 343                 line6_stream_stop(line6pcm, dir, type);
 344         for (dir = 0; dir < 2; dir++) {
 345                 pstr = get_stream(line6pcm, dir);
 346                 line6_buffer_release(line6pcm, pstr, type);
 347         }
 348         mutex_unlock(&line6pcm->state_mutex);
 349 }
 350 EXPORT_SYMBOL_GPL(line6_pcm_release);
 351
 352 /* common PCM hw_params callback */
 353 int snd_line6_hw_params(struct snd_pcm_substream *substream,
 354                         struct snd_pcm_hw_params *hw_params)
 355 {
 356         int ret;
 357         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 358         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 359
 360         mutex_lock(&line6pcm->state_mutex);
 361         ret = line6_buffer_acquire(line6pcm, pstr, substream->stream,
 362                                    LINE6_STREAM_PCM);
 363         if (ret < 0)
 364                 goto error;
 365
 366         ret = snd_pcm_lib_malloc_pages(substream,
 367                                        params_buffer_bytes(hw_params));
 368         if (ret < 0) {
 369                 line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
 370                 goto error;
 371         }
 372
 373         pstr->period = params_period_bytes(hw_params);
 374  error:
 375         mutex_unlock(&line6pcm->state_mutex);
 376         return ret;
 377 }
 378
 379 /* common PCM hw_free callback */
 380 int snd_line6_hw_free(struct snd_pcm_substream *substream)
 381 {
 382         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 383         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 384
 385         mutex_lock(&line6pcm->state_mutex);
 386         line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
 387         mutex_unlock(&line6pcm->state_mutex);
 388         return snd_pcm_lib_free_pages(substream);
 389 }
 390
 391
 392 /* control info callback */
 393 static int snd_line6_control_playback_info(struct snd_kcontrol *kcontrol,
 394                                            struct snd_ctl_elem_info *uinfo)
 395 {
 396         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 397         uinfo->count = 2;
 398         uinfo->value.integer.min = 0;
 399         uinfo->value.integer.max = 256;
 400         return 0;
 401 }
 402
 403 /* control get callback */
 404 static int snd_line6_control_playback_get(struct snd_kcontrol *kcontrol,
 405                                           struct snd_ctl_elem_value *ucontrol)
 406 {
 407         int i;
 408         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 409
 410         for (i = 0; i < 2; i++)
 411                 ucontrol->value.integer.value[i] = line6pcm->volume_playback[i];
 412
 413         return 0;
 414 }
 415
 416 /* control put callback */
 417 static int snd_line6_control_playback_put(struct snd_kcontrol *kcontrol,
 418                                           struct snd_ctl_elem_value *ucontrol)
 419 {
 420         int i, changed = 0;
 421         struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
 422
 423         for (i = 0; i < 2; i++)
 424                 if (line6pcm->volume_playback[i] !=
 425                     ucontrol->value.integer.value[i]) {
 426                         line6pcm->volume_playback[i] =
 427                             ucontrol->value.integer.value[i];
 428                         changed = 1;
 429                 }
 430
 431         return changed;
 432 }
 433
 434 /* control definition */
 435 static const struct snd_kcontrol_new line6_controls[] = {
 436         {
 437                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 438                 .name = "PCM Playback Volume",
 439                 .info = snd_line6_control_playback_info,
 440                 .get = snd_line6_control_playback_get,
 441                 .put = snd_line6_control_playback_put
 442         },
 443         {
 444                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 445                 .name = "Impulse Response Volume",
 446                 .info = snd_line6_impulse_volume_info,
 447                 .get = snd_line6_impulse_volume_get,
 448                 .put = snd_line6_impulse_volume_put
 449         },
 450         {
 451                 .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 452                 .name = "Impulse Response Period",
 453                 .info = snd_line6_impulse_period_info,
 454                 .get = snd_line6_impulse_period_get,
 455                 .put = snd_line6_impulse_period_put
 456         },
 457 };
 458
 459 /*
 460         Cleanup the PCM device.
 461 */
 462 static void cleanup_urbs(struct line6_pcm_stream *pcms, int iso_buffers)
 463 {
 464         int i;
 465
 466         /* Most likely impossible in current code... */
 467         if (pcms->urbs == NULL)
 468                 return;
 469
 470         for (i = 0; i < iso_buffers; i++) {
 471                 if (pcms->urbs[i]) {
 472                         usb_kill_urb(pcms->urbs[i]);
 473                         usb_free_urb(pcms->urbs[i]);
 474                 }
 475         }
 476         kfree(pcms->urbs);
 477         pcms->urbs = NULL;
 478 }
 479
 480 static void line6_cleanup_pcm(struct snd_pcm *pcm)
 481 {
 482         struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);
 483
 484         cleanup_urbs(&line6pcm->out, line6pcm->line6->iso_buffers);
 485         cleanup_urbs(&line6pcm->in, line6pcm->line6->iso_buffers);
 486         kfree(line6pcm);
 487 }
 488
 489 /* create a PCM device */
 490 static int snd_line6_new_pcm(struct usb_line6 *line6, struct snd_pcm **pcm_ret)
 491 {
 492         struct snd_pcm *pcm;
 493         int err;
 494
 495         err = snd_pcm_new(line6->card, (char *)line6->properties->name,
 496                           0, 1, 1, pcm_ret);
 497         if (err < 0)
 498                 return err;
 499         pcm = *pcm_ret;
 500         strcpy(pcm->name, line6->properties->name);
 501
 502         /* set operators */
 503         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 504                         &snd_line6_playback_ops);
 505         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_line6_capture_ops);
 506
 507         /* pre-allocation of buffers */
 508         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 509                                               snd_dma_continuous_data
 510                                               (GFP_KERNEL), 64 * 1024,
 511                                               128 * 1024);
 512         return 0;
 513 }
 514
 515 /*
 516         Sync with PCM stream stops.
 517 */
 518 void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm)
 519 {
 520         line6_unlink_audio_urbs(line6pcm, &line6pcm->out);
 521         line6_unlink_audio_urbs(line6pcm, &line6pcm->in);
 522         line6_wait_clear_audio_urbs(line6pcm, &line6pcm->out);
 523         line6_wait_clear_audio_urbs(line6pcm, &line6pcm->in);
 524 }
 525
 526 /*
 527         Create and register the PCM device and mixer entries.
 528         Create URBs for playback and capture.
 529 */
 530 int line6_init_pcm(struct usb_line6 *line6,
 531                    struct line6_pcm_properties *properties)
 532 {
 533         int i, err;
 534         unsigned ep_read = line6->properties->ep_audio_r;
 535         unsigned ep_write = line6->properties->ep_audio_w;
 536         struct snd_pcm *pcm;
 537         struct snd_line6_pcm *line6pcm;
 538
 539         if (!(line6->properties->capabilities & LINE6_CAP_PCM))
 540                 return 0;       /* skip PCM initialization and report success */
 541
 542         err = snd_line6_new_pcm(line6, &pcm);
 543         if (err < 0)
 544                 return err;
 545
 546         line6pcm = kzalloc(sizeof(*line6pcm), GFP_KERNEL);
 547         if (!line6pcm)
 548                 return -ENOMEM;
 549
 550         mutex_init(&line6pcm->state_mutex);
 551         line6pcm->pcm = pcm;
 552         line6pcm->properties = properties;
 553         line6pcm->volume_playback[0] = line6pcm->volume_playback[1] = 255;
 554         line6pcm->volume_monitor = 255;
 555         line6pcm->line6 = line6;
 556
 557         spin_lock_init(&line6pcm->out.lock);
 558         spin_lock_init(&line6pcm->in.lock);
 559         line6pcm->impulse_period = LINE6_IMPULSE_DEFAULT_PERIOD;
 560
 561         line6->line6pcm = line6pcm;
 562
 563         pcm->private_data = line6pcm;
 564         pcm->private_free = line6_cleanup_pcm;
 565
 566         line6pcm->max_packet_size_in =
 567                 usb_maxpacket(line6->usbdev,
 568                         usb_rcvisocpipe(line6->usbdev, ep_read), 0);
 569         line6pcm->max_packet_size_out =
 570                 usb_maxpacket(line6->usbdev,
 571                         usb_sndisocpipe(line6->usbdev, ep_write), 1);
 572         if (!line6pcm->max_packet_size_in || !line6pcm->max_packet_size_out) {
 573                 dev_err(line6pcm->line6->ifcdev,
 574                         "cannot get proper max packet size\n");
 575                 return -EINVAL;
 576         }
 577
 578         err = line6_create_audio_out_urbs(line6pcm);
 579         if (err < 0)
 580                 return err;
 581
 582         err = line6_create_audio_in_urbs(line6pcm);
 583         if (err < 0)
 584                 return err;
 585
 586         /* mixer: */
 587         for (i = 0; i < ARRAY_SIZE(line6_controls); i++) {
 588                 err = snd_ctl_add(line6->card,
 589                                   snd_ctl_new1(&line6_controls[i], line6pcm));
 590                 if (err < 0)
 591                         return err;
 592         }
 593
 594         return 0;
 595 }
 596 EXPORT_SYMBOL_GPL(line6_init_pcm);
 597
 598 /* prepare pcm callback */
 599 int snd_line6_prepare(struct snd_pcm_substream *substream)
 600 {
 601         struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
 602         struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
 603
 604         mutex_lock(&line6pcm->state_mutex);
 605         if (!pstr->running)
 606                 line6_wait_clear_audio_urbs(line6pcm, pstr);
 607
 608         if (!test_and_set_bit(LINE6_FLAG_PREPARED, &line6pcm->flags)) {
 609                 line6pcm->out.count = 0;
 610                 line6pcm->out.pos = 0;
 611                 line6pcm->out.pos_done = 0;
 612                 line6pcm->out.bytes = 0;
 613                 line6pcm->in.count = 0;
 614                 line6pcm->in.pos_done = 0;
 615                 line6pcm->in.bytes = 0;
 616         }
 617
 618         mutex_unlock(&line6pcm->state_mutex);
 619         return 0;
 620 }