sound/core/pcm.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <[email protected]>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/time.h>
  25 #include <linux/mutex.h>
  26 #include <sound/core.h>
  27 #include <sound/minors.h>
  28 #include <sound/pcm.h>
  29 #include <sound/control.h>
  30 #include <sound/info.h>
  31
  32 MODULE_AUTHOR("Jaroslav Kysela <[email protected]>, Abramo Bagnara <[email protected]>");
  33 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  34 MODULE_LICENSE("GPL");
  35
  36 static LIST_HEAD(snd_pcm_devices);
  37 static LIST_HEAD(snd_pcm_notify_list);
  38 static DEFINE_MUTEX(register_mutex);
  39
  40 static int snd_pcm_free(struct snd_pcm *pcm);
  41 static int snd_pcm_dev_free(struct snd_device *device);
  42 static int snd_pcm_dev_register(struct snd_device *device);
  43 static int snd_pcm_dev_disconnect(struct snd_device *device);
  44
  45 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  46 {
  47         struct snd_pcm *pcm;
  48
  49         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  50                 if (pcm->card == card && pcm->device == device)
  51                         return pcm;
  52         }
  53         return NULL;
  54 }
  55
  56 static int snd_pcm_next(struct snd_card *card, int device)
  57 {
  58         struct snd_pcm *pcm;
  59
  60         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  61                 if (pcm->card == card && pcm->device > device)
  62                         return pcm->device;
  63                 else if (pcm->card->number > card->number)
  64                         return -1;
  65         }
  66         return -1;
  67 }
  68
  69 static int snd_pcm_add(struct snd_pcm *newpcm)
  70 {
  71         struct snd_pcm *pcm;
  72
  73         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  74                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  75                         return -EBUSY;
  76                 if (pcm->card->number > newpcm->card->number ||
  77                                 (pcm->card == newpcm->card &&
  78                                 pcm->device > newpcm->device)) {
  79                         list_add(&newpcm->list, pcm->list.prev);
  80                         return 0;
  81                 }
  82         }
  83         list_add_tail(&newpcm->list, &snd_pcm_devices);
  84         return 0;
  85 }
  86
  87 static int snd_pcm_control_ioctl(struct snd_card *card,
  88                                  struct snd_ctl_file *control,
  89                                  unsigned int cmd, unsigned long arg)
  90 {
  91         switch (cmd) {
  92         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
  93                 {
  94                         int device;
  95
  96                         if (get_user(device, (int __user *)arg))
  97                                 return -EFAULT;
  98                         mutex_lock(&register_mutex);
  99                         device = snd_pcm_next(card, device);
 100                         mutex_unlock(&register_mutex);
 101                         if (put_user(device, (int __user *)arg))
 102                                 return -EFAULT;
 103                         return 0;
 104                 }
 105         case SNDRV_CTL_IOCTL_PCM_INFO:
 106                 {
 107                         struct snd_pcm_info __user *info;
 108                         unsigned int device, subdevice;
 109                         int stream;
 110                         struct snd_pcm *pcm;
 111                         struct snd_pcm_str *pstr;
 112                         struct snd_pcm_substream *substream;
 113                         int err;
 114
 115                         info = (struct snd_pcm_info __user *)arg;
 116                         if (get_user(device, &info->device))
 117                                 return -EFAULT;
 118                         if (get_user(stream, &info->stream))
 119                                 return -EFAULT;
 120                         if (stream < 0 || stream > 1)
 121                                 return -EINVAL;
 122                         if (get_user(subdevice, &info->subdevice))
 123                                 return -EFAULT;
 124                         mutex_lock(&register_mutex);
 125                         pcm = snd_pcm_get(card, device);
 126                         if (pcm == NULL) {
 127                                 err = -ENXIO;
 128                                 goto _error;
 129                         }
 130                         pstr = &pcm->streams[stream];
 131                         if (pstr->substream_count == 0) {
 132                                 err = -ENOENT;
 133                                 goto _error;
 134                         }
 135                         if (subdevice >= pstr->substream_count) {
 136                                 err = -ENXIO;
 137                                 goto _error;
 138                         }
 139                         for (substream = pstr->substream; substream;
 140                              substream = substream->next)
 141                                 if (substream->number == (int)subdevice)
 142                                         break;
 143                         if (substream == NULL) {
 144                                 err = -ENXIO;
 145                                 goto _error;
 146                         }
 147                         err = snd_pcm_info_user(substream, info);
 148                 _error:
 149                         mutex_unlock(&register_mutex);
 150                         return err;
 151                 }
 152         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 153                 {
 154                         int val;
 155
 156                         if (get_user(val, (int __user *)arg))
 157                                 return -EFAULT;
 158                         control->prefer_pcm_subdevice = val;
 159                         return 0;
 160                 }
 161         }
 162         return -ENOIOCTLCMD;
 163 }
 164
 165 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 166
 167 static char *snd_pcm_format_names[] = {
 168         FORMAT(S8),
 169         FORMAT(U8),
 170         FORMAT(S16_LE),
 171         FORMAT(S16_BE),
 172         FORMAT(U16_LE),
 173         FORMAT(U16_BE),
 174         FORMAT(S24_LE),
 175         FORMAT(S24_BE),
 176         FORMAT(U24_LE),
 177         FORMAT(U24_BE),
 178         FORMAT(S32_LE),
 179         FORMAT(S32_BE),
 180         FORMAT(U32_LE),
 181         FORMAT(U32_BE),
 182         FORMAT(FLOAT_LE),
 183         FORMAT(FLOAT_BE),
 184         FORMAT(FLOAT64_LE),
 185         FORMAT(FLOAT64_BE),
 186         FORMAT(IEC958_SUBFRAME_LE),
 187         FORMAT(IEC958_SUBFRAME_BE),
 188         FORMAT(MU_LAW),
 189         FORMAT(A_LAW),
 190         FORMAT(IMA_ADPCM),
 191         FORMAT(MPEG),
 192         FORMAT(GSM),
 193         FORMAT(SPECIAL),
 194         FORMAT(S24_3LE),
 195         FORMAT(S24_3BE),
 196         FORMAT(U24_3LE),
 197         FORMAT(U24_3BE),
 198         FORMAT(S20_3LE),
 199         FORMAT(S20_3BE),
 200         FORMAT(U20_3LE),
 201         FORMAT(U20_3BE),
 202         FORMAT(S18_3LE),
 203         FORMAT(S18_3BE),
 204         FORMAT(U18_3LE),
 205         FORMAT(U18_3BE),
 206         FORMAT(G723_24),
 207         FORMAT(G723_24_1B),
 208         FORMAT(G723_40),
 209         FORMAT(G723_40_1B),
 210 };
 211
 212 const char *snd_pcm_format_name(snd_pcm_format_t format)
 213 {
 214         if (format >= ARRAY_SIZE(snd_pcm_format_names))
 215                 return "Unknown";
 216         return snd_pcm_format_names[format];
 217 }
 218 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 219
 220 #ifdef CONFIG_SND_VERBOSE_PROCFS
 221
 222 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 223 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 224 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 225 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 226 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 227 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 228 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 229 #define START(v) [SNDRV_PCM_START_##v] = #v
 230 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 231
 232 static char *snd_pcm_stream_names[] = {
 233         STREAM(PLAYBACK),
 234         STREAM(CAPTURE),
 235 };
 236
 237 static char *snd_pcm_state_names[] = {
 238         STATE(OPEN),
 239         STATE(SETUP),
 240         STATE(PREPARED),
 241         STATE(RUNNING),
 242         STATE(XRUN),
 243         STATE(DRAINING),
 244         STATE(PAUSED),
 245         STATE(SUSPENDED),
 246 };
 247
 248 static char *snd_pcm_access_names[] = {
 249         ACCESS(MMAP_INTERLEAVED),
 250         ACCESS(MMAP_NONINTERLEAVED),
 251         ACCESS(MMAP_COMPLEX),
 252         ACCESS(RW_INTERLEAVED),
 253         ACCESS(RW_NONINTERLEAVED),
 254 };
 255
 256 static char *snd_pcm_subformat_names[] = {
 257         SUBFORMAT(STD),
 258 };
 259
 260 static char *snd_pcm_tstamp_mode_names[] = {
 261         TSTAMP(NONE),
 262         TSTAMP(ENABLE),
 263 };
 264
 265 static const char *snd_pcm_stream_name(int stream)
 266 {
 267         return snd_pcm_stream_names[stream];
 268 }
 269
 270 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 271 {
 272         return snd_pcm_access_names[access];
 273 }
 274
 275 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 276 {
 277         return snd_pcm_subformat_names[subformat];
 278 }
 279
 280 static const char *snd_pcm_tstamp_mode_name(int mode)
 281 {
 282         return snd_pcm_tstamp_mode_names[mode];
 283 }
 284
 285 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 286 {
 287         return snd_pcm_state_names[state];
 288 }
 289
 290 #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
 291 #include <linux/soundcard.h>
 292
 293 static const char *snd_pcm_oss_format_name(int format)
 294 {
 295         switch (format) {
 296         case AFMT_MU_LAW:
 297                 return "MU_LAW";
 298         case AFMT_A_LAW:
 299                 return "A_LAW";
 300         case AFMT_IMA_ADPCM:
 301                 return "IMA_ADPCM";
 302         case AFMT_U8:
 303                 return "U8";
 304         case AFMT_S16_LE:
 305                 return "S16_LE";
 306         case AFMT_S16_BE:
 307                 return "S16_BE";
 308         case AFMT_S8:
 309                 return "S8";
 310         case AFMT_U16_LE:
 311                 return "U16_LE";
 312         case AFMT_U16_BE:
 313                 return "U16_BE";
 314         case AFMT_MPEG:
 315                 return "MPEG";
 316         default:
 317                 return "unknown";
 318         }
 319 }
 320 #endif
 321
 322 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 323                                    struct snd_info_buffer *buffer)
 324 {
 325         struct snd_pcm_info *info;
 326         int err;
 327
 328         if (! substream)
 329                 return;
 330
 331         info = kmalloc(sizeof(*info), GFP_KERNEL);
 332         if (! info) {
 333                 printk(KERN_DEBUG "snd_pcm_proc_info_read: cannot malloc\n");
 334                 return;
 335         }
 336
 337         err = snd_pcm_info(substream, info);
 338         if (err < 0) {
 339                 snd_iprintf(buffer, "error %d\n", err);
 340                 kfree(info);
 341                 return;
 342         }
 343         snd_iprintf(buffer, "card: %d\n", info->card);
 344         snd_iprintf(buffer, "device: %d\n", info->device);
 345         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 346         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 347         snd_iprintf(buffer, "id: %s\n", info->id);
 348         snd_iprintf(buffer, "name: %s\n", info->name);
 349         snd_iprintf(buffer, "subname: %s\n", info->subname);
 350         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 351         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 352         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 353         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 354         kfree(info);
 355 }
 356
 357 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 358                                           struct snd_info_buffer *buffer)
 359 {
 360         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 361                                buffer);
 362 }
 363
 364 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 365                                              struct snd_info_buffer *buffer)
 366 {
 367         snd_pcm_proc_info_read(entry->private_data, buffer);
 368 }
 369
 370 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 371                                                   struct snd_info_buffer *buffer)
 372 {
 373         struct snd_pcm_substream *substream = entry->private_data;
 374         struct snd_pcm_runtime *runtime;
 375
 376         mutex_lock(&substream->pcm->open_mutex);
 377         runtime = substream->runtime;
 378         if (!runtime) {
 379                 snd_iprintf(buffer, "closed\n");
 380                 goto unlock;
 381         }
 382         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 383                 snd_iprintf(buffer, "no setup\n");
 384                 goto unlock;
 385         }
 386         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 387         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 388         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 389         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 390         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 391         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 392         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 393 #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
 394         if (substream->oss.oss) {
 395                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 396                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 397                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 398                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 399                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 400                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 401         }
 402 #endif
 403  unlock:
 404         mutex_unlock(&substream->pcm->open_mutex);
 405 }
 406
 407 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 408                                                   struct snd_info_buffer *buffer)
 409 {
 410         struct snd_pcm_substream *substream = entry->private_data;
 411         struct snd_pcm_runtime *runtime;
 412
 413         mutex_lock(&substream->pcm->open_mutex);
 414         runtime = substream->runtime;
 415         if (!runtime) {
 416                 snd_iprintf(buffer, "closed\n");
 417                 goto unlock;
 418         }
 419         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 420                 snd_iprintf(buffer, "no setup\n");
 421                 goto unlock;
 422         }
 423         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 424         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 425         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 426         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 427         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 428         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 429         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 430         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 431  unlock:
 432         mutex_unlock(&substream->pcm->open_mutex);
 433 }
 434
 435 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 436                                                struct snd_info_buffer *buffer)
 437 {
 438         struct snd_pcm_substream *substream = entry->private_data;
 439         struct snd_pcm_runtime *runtime;
 440         struct snd_pcm_status status;
 441         int err;
 442
 443         mutex_lock(&substream->pcm->open_mutex);
 444         runtime = substream->runtime;
 445         if (!runtime) {
 446                 snd_iprintf(buffer, "closed\n");
 447                 goto unlock;
 448         }
 449         memset(&status, 0, sizeof(status));
 450         err = snd_pcm_status(substream, &status);
 451         if (err < 0) {
 452                 snd_iprintf(buffer, "error %d\n", err);
 453                 goto unlock;
 454         }
 455         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 456         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 457         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 458                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 459         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 460                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 461         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 462         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 463         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 464         snd_iprintf(buffer, "-----\n");
 465         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 466         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 467  unlock:
 468         mutex_unlock(&substream->pcm->open_mutex);
 469 }
 470
 471 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 472 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 473                                     struct snd_info_buffer *buffer)
 474 {
 475         struct snd_pcm_str *pstr = entry->private_data;
 476         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 477 }
 478
 479 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 480                                      struct snd_info_buffer *buffer)
 481 {
 482         struct snd_pcm_str *pstr = entry->private_data;
 483         char line[64];
 484         if (!snd_info_get_line(buffer, line, sizeof(line)))
 485                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 486 }
 487 #endif
 488
 489 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 490 {
 491         struct snd_pcm *pcm = pstr->pcm;
 492         struct snd_info_entry *entry;
 493         char name[16];
 494
 495         sprintf(name, "pcm%i%c", pcm->device,
 496                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 497         if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
 498                 return -ENOMEM;
 499         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 500         if (snd_info_register(entry) < 0) {
 501                 snd_info_free_entry(entry);
 502                 return -ENOMEM;
 503         }
 504         pstr->proc_root = entry;
 505
 506         if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
 507                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 508                 if (snd_info_register(entry) < 0) {
 509                         snd_info_free_entry(entry);
 510                         entry = NULL;
 511                 }
 512         }
 513         pstr->proc_info_entry = entry;
 514
 515 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 516         if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 517                                                 pstr->proc_root)) != NULL) {
 518                 entry->c.text.read = snd_pcm_xrun_debug_read;
 519                 entry->c.text.write = snd_pcm_xrun_debug_write;
 520                 entry->mode |= S_IWUSR;
 521                 entry->private_data = pstr;
 522                 if (snd_info_register(entry) < 0) {
 523                         snd_info_free_entry(entry);
 524                         entry = NULL;
 525                 }
 526         }
 527         pstr->proc_xrun_debug_entry = entry;
 528 #endif
 529         return 0;
 530 }
 531
 532 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 533 {
 534 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 535         snd_info_free_entry(pstr->proc_xrun_debug_entry);
 536         pstr->proc_xrun_debug_entry = NULL;
 537 #endif
 538         snd_info_free_entry(pstr->proc_info_entry);
 539         pstr->proc_info_entry = NULL;
 540         snd_info_free_entry(pstr->proc_root);
 541         pstr->proc_root = NULL;
 542         return 0;
 543 }
 544
 545 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 546 {
 547         struct snd_info_entry *entry;
 548         struct snd_card *card;
 549         char name[16];
 550
 551         card = substream->pcm->card;
 552
 553         sprintf(name, "sub%i", substream->number);
 554         if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
 555                 return -ENOMEM;
 556         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 557         if (snd_info_register(entry) < 0) {
 558                 snd_info_free_entry(entry);
 559                 return -ENOMEM;
 560         }
 561         substream->proc_root = entry;
 562
 563         if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
 564                 snd_info_set_text_ops(entry, substream,
 565                                       snd_pcm_substream_proc_info_read);
 566                 if (snd_info_register(entry) < 0) {
 567                         snd_info_free_entry(entry);
 568                         entry = NULL;
 569                 }
 570         }
 571         substream->proc_info_entry = entry;
 572
 573         if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
 574                 snd_info_set_text_ops(entry, substream,
 575                                       snd_pcm_substream_proc_hw_params_read);
 576                 if (snd_info_register(entry) < 0) {
 577                         snd_info_free_entry(entry);
 578                         entry = NULL;
 579                 }
 580         }
 581         substream->proc_hw_params_entry = entry;
 582
 583         if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
 584                 snd_info_set_text_ops(entry, substream,
 585                                       snd_pcm_substream_proc_sw_params_read);
 586                 if (snd_info_register(entry) < 0) {
 587                         snd_info_free_entry(entry);
 588                         entry = NULL;
 589                 }
 590         }
 591         substream->proc_sw_params_entry = entry;
 592
 593         if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
 594                 snd_info_set_text_ops(entry, substream,
 595                                       snd_pcm_substream_proc_status_read);
 596                 if (snd_info_register(entry) < 0) {
 597                         snd_info_free_entry(entry);
 598                         entry = NULL;
 599                 }
 600         }
 601         substream->proc_status_entry = entry;
 602
 603         return 0;
 604 }
 605
 606 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
 607 {
 608         snd_info_free_entry(substream->proc_info_entry);
 609         substream->proc_info_entry = NULL;
 610         snd_info_free_entry(substream->proc_hw_params_entry);
 611         substream->proc_hw_params_entry = NULL;
 612         snd_info_free_entry(substream->proc_sw_params_entry);
 613         substream->proc_sw_params_entry = NULL;
 614         snd_info_free_entry(substream->proc_status_entry);
 615         substream->proc_status_entry = NULL;
 616         snd_info_free_entry(substream->proc_root);
 617         substream->proc_root = NULL;
 618         return 0;
 619 }
 620 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 621 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 622 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 623 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 624 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 625 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 626
 627 /**
 628  * snd_pcm_new_stream - create a new PCM stream
 629  * @pcm: the pcm instance
 630  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 631  * @substream_count: the number of substreams
 632  *
 633  * Creates a new stream for the pcm.
 634  * The corresponding stream on the pcm must have been empty before
 635  * calling this, i.e. zero must be given to the argument of
 636  * snd_pcm_new().
 637  *
 638  * Returns zero if successful, or a negative error code on failure.
 639  */
 640 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 641 {
 642         int idx, err;
 643         struct snd_pcm_str *pstr = &pcm->streams[stream];
 644         struct snd_pcm_substream *substream, *prev;
 645
 646 #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
 647         mutex_init(&pstr->oss.setup_mutex);
 648 #endif
 649         pstr->stream = stream;
 650         pstr->pcm = pcm;
 651         pstr->substream_count = substream_count;
 652         if (substream_count > 0) {
 653                 err = snd_pcm_stream_proc_init(pstr);
 654                 if (err < 0) {
 655                         snd_printk(KERN_ERR "Error in snd_pcm_stream_proc_init\n");
 656                         return err;
 657                 }
 658         }
 659         prev = NULL;
 660         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 661                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 662                 if (substream == NULL) {
 663                         snd_printk(KERN_ERR "Cannot allocate PCM substream\n");
 664                         return -ENOMEM;
 665                 }
 666                 substream->pcm = pcm;
 667                 substream->pstr = pstr;
 668                 substream->number = idx;
 669                 substream->stream = stream;
 670                 sprintf(substream->name, "subdevice #%i", idx);
 671                 substream->buffer_bytes_max = UINT_MAX;
 672                 if (prev == NULL)
 673                         pstr->substream = substream;
 674                 else
 675                         prev->next = substream;
 676                 err = snd_pcm_substream_proc_init(substream);
 677                 if (err < 0) {
 678                         snd_printk(KERN_ERR "Error in snd_pcm_stream_proc_init\n");
 679                         if (prev == NULL)
 680                                 pstr->substream = NULL;
 681                         else
 682                                 prev->next = NULL;
 683                         kfree(substream);
 684                         return err;
 685                 }
 686                 substream->group = &substream->self_group;
 687                 spin_lock_init(&substream->self_group.lock);
 688                 INIT_LIST_HEAD(&substream->self_group.substreams);
 689                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 690                 atomic_set(&substream->mmap_count, 0);
 691                 prev = substream;
 692         }
 693         return 0;
 694 }
 695
 696 EXPORT_SYMBOL(snd_pcm_new_stream);
 697
 698 /**
 699  * snd_pcm_new - create a new PCM instance
 700  * @card: the card instance
 701  * @id: the id string
 702  * @device: the device index (zero based)
 703  * @playback_count: the number of substreams for playback
 704  * @capture_count: the number of substreams for capture
 705  * @rpcm: the pointer to store the new pcm instance
 706  *
 707  * Creates a new PCM instance.
 708  *
 709  * The pcm operators have to be set afterwards to the new instance
 710  * via snd_pcm_set_ops().
 711  *
 712  * Returns zero if successful, or a negative error code on failure.
 713  */
 714 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 715                 int playback_count, int capture_count,
 716                 struct snd_pcm ** rpcm)
 717 {
 718         struct snd_pcm *pcm;
 719         int err;
 720         static struct snd_device_ops ops = {
 721                 .dev_free = snd_pcm_dev_free,
 722                 .dev_register = snd_pcm_dev_register,
 723                 .dev_disconnect = snd_pcm_dev_disconnect,
 724         };
 725
 726         if (snd_BUG_ON(!card))
 727                 return -ENXIO;
 728         if (rpcm)
 729                 *rpcm = NULL;
 730         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 731         if (pcm == NULL) {
 732                 snd_printk(KERN_ERR "Cannot allocate PCM\n");
 733                 return -ENOMEM;
 734         }
 735         pcm->card = card;
 736         pcm->device = device;
 737         if (id)
 738                 strlcpy(pcm->id, id, sizeof(pcm->id));
 739         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
 740                 snd_pcm_free(pcm);
 741                 return err;
 742         }
 743         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
 744                 snd_pcm_free(pcm);
 745                 return err;
 746         }
 747         mutex_init(&pcm->open_mutex);
 748         init_waitqueue_head(&pcm->open_wait);
 749         if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
 750                 snd_pcm_free(pcm);
 751                 return err;
 752         }
 753         if (rpcm)
 754                 *rpcm = pcm;
 755         return 0;
 756 }
 757
 758 EXPORT_SYMBOL(snd_pcm_new);
 759
 760 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 761 {
 762         struct snd_pcm_substream *substream, *substream_next;
 763 #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
 764         struct snd_pcm_oss_setup *setup, *setupn;
 765 #endif
 766         substream = pstr->substream;
 767         while (substream) {
 768                 substream_next = substream->next;
 769                 snd_pcm_timer_done(substream);
 770                 snd_pcm_substream_proc_done(substream);
 771                 kfree(substream);
 772                 substream = substream_next;
 773         }
 774         snd_pcm_stream_proc_done(pstr);
 775 #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
 776         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 777                 setupn = setup->next;
 778                 kfree(setup->task_name);
 779                 kfree(setup);
 780         }
 781 #endif
 782 }
 783
 784 static int snd_pcm_free(struct snd_pcm *pcm)
 785 {
 786         struct snd_pcm_notify *notify;
 787
 788         if (!pcm)
 789                 return 0;
 790         list_for_each_entry(notify, &snd_pcm_notify_list, list) {
 791                 notify->n_unregister(pcm);
 792         }
 793         if (pcm->private_free)
 794                 pcm->private_free(pcm);
 795         snd_pcm_lib_preallocate_free_for_all(pcm);
 796         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 797         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 798         kfree(pcm);
 799         return 0;
 800 }
 801
 802 static int snd_pcm_dev_free(struct snd_device *device)
 803 {
 804         struct snd_pcm *pcm = device->device_data;
 805         return snd_pcm_free(pcm);
 806 }
 807
 808 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 809                              struct file *file,
 810                              struct snd_pcm_substream **rsubstream)
 811 {
 812         struct snd_pcm_str * pstr;
 813         struct snd_pcm_substream *substream;
 814         struct snd_pcm_runtime *runtime;
 815         struct snd_ctl_file *kctl;
 816         struct snd_card *card;
 817         int prefer_subdevice = -1;
 818         size_t size;
 819
 820         if (snd_BUG_ON(!pcm || !rsubstream))
 821                 return -ENXIO;
 822         *rsubstream = NULL;
 823         pstr = &pcm->streams[stream];
 824         if (pstr->substream == NULL || pstr->substream_count == 0)
 825                 return -ENODEV;
 826
 827         card = pcm->card;
 828         read_lock(&card->ctl_files_rwlock);
 829         list_for_each_entry(kctl, &card->ctl_files, list) {
 830                 if (kctl->pid == task_pid(current)) {
 831                         prefer_subdevice = kctl->prefer_pcm_subdevice;
 832                         if (prefer_subdevice != -1)
 833                                 break;
 834                 }
 835         }
 836         read_unlock(&card->ctl_files_rwlock);
 837
 838         switch (stream) {
 839         case SNDRV_PCM_STREAM_PLAYBACK:
 840                 if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 841                         for (substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; substream; substream = substream->next) {
 842                                 if (SUBSTREAM_BUSY(substream))
 843                                         return -EAGAIN;
 844                         }
 845                 }
 846                 break;
 847         case SNDRV_PCM_STREAM_CAPTURE:
 848                 if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 849                         for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next) {
 850                                 if (SUBSTREAM_BUSY(substream))
 851                                         return -EAGAIN;
 852                         }
 853                 }
 854                 break;
 855         default:
 856                 return -EINVAL;
 857         }
 858
 859         if (file->f_flags & O_APPEND) {
 860                 if (prefer_subdevice < 0) {
 861                         if (pstr->substream_count > 1)
 862                                 return -EINVAL; /* must be unique */
 863                         substream = pstr->substream;
 864                 } else {
 865                         for (substream = pstr->substream; substream;
 866                              substream = substream->next)
 867                                 if (substream->number == prefer_subdevice)
 868                                         break;
 869                 }
 870                 if (! substream)
 871                         return -ENODEV;
 872                 if (! SUBSTREAM_BUSY(substream))
 873                         return -EBADFD;
 874                 substream->ref_count++;
 875                 *rsubstream = substream;
 876                 return 0;
 877         }
 878
 879         if (prefer_subdevice >= 0) {
 880                 for (substream = pstr->substream; substream; substream = substream->next)
 881                         if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
 882                                 goto __ok;
 883         }
 884         for (substream = pstr->substream; substream; substream = substream->next)
 885                 if (!SUBSTREAM_BUSY(substream))
 886                         break;
 887       __ok:
 888         if (substream == NULL)
 889                 return -EAGAIN;
 890
 891         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 892         if (runtime == NULL)
 893                 return -ENOMEM;
 894
 895         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 896         runtime->status = snd_malloc_pages(size, GFP_KERNEL);
 897         if (runtime->status == NULL) {
 898                 kfree(runtime);
 899                 return -ENOMEM;
 900         }
 901         memset((void*)runtime->status, 0, size);
 902
 903         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 904         runtime->control = snd_malloc_pages(size, GFP_KERNEL);
 905         if (runtime->control == NULL) {
 906                 snd_free_pages((void*)runtime->status,
 907                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 908                 kfree(runtime);
 909                 return -ENOMEM;
 910         }
 911         memset((void*)runtime->control, 0, size);
 912
 913         init_waitqueue_head(&runtime->sleep);
 914         init_waitqueue_head(&runtime->tsleep);
 915
 916         runtime->status->state = SNDRV_PCM_STATE_OPEN;
 917
 918         substream->runtime = runtime;
 919         substream->private_data = pcm->private_data;
 920         substream->ref_count = 1;
 921         substream->f_flags = file->f_flags;
 922         substream->pid = get_pid(task_pid(current));
 923         pstr->substream_opened++;
 924         *rsubstream = substream;
 925         return 0;
 926 }
 927
 928 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 929 {
 930         struct snd_pcm_runtime *runtime;
 931
 932         if (PCM_RUNTIME_CHECK(substream))
 933                 return;
 934         runtime = substream->runtime;
 935         if (runtime->private_free != NULL)
 936                 runtime->private_free(runtime);
 937         snd_free_pages((void*)runtime->status,
 938                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 939         snd_free_pages((void*)runtime->control,
 940                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
 941         kfree(runtime->hw_constraints.rules);
 942 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 943         if (runtime->hwptr_log)
 944                 kfree(runtime->hwptr_log);
 945 #endif
 946         kfree(runtime);
 947         substream->runtime = NULL;
 948         put_pid(substream->pid);
 949         substream->pid = NULL;
 950         substream->pstr->substream_opened--;
 951 }
 952
 953 static ssize_t show_pcm_class(struct device *dev,
 954                               struct device_attribute *attr, char *buf)
 955 {
 956         struct snd_pcm *pcm;
 957         const char *str;
 958         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
 959                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
 960                 [SNDRV_PCM_CLASS_MULTI] = "multi",
 961                 [SNDRV_PCM_CLASS_MODEM] = "modem",
 962                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
 963         };
 964
 965         if (! (pcm = dev_get_drvdata(dev)) ||
 966             pcm->dev_class > SNDRV_PCM_CLASS_LAST)
 967                 str = "none";
 968         else
 969                 str = strs[pcm->dev_class];
 970         return snprintf(buf, PAGE_SIZE, "%s\n", str);
 971 }
 972
 973 static struct device_attribute pcm_attrs =
 974         __ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
 975
 976 static int snd_pcm_dev_register(struct snd_device *device)
 977 {
 978         int cidx, err;
 979         struct snd_pcm_substream *substream;
 980         struct snd_pcm_notify *notify;
 981         char str[16];
 982         struct snd_pcm *pcm;
 983         struct device *dev;
 984
 985         if (snd_BUG_ON(!device || !device->device_data))
 986                 return -ENXIO;
 987         pcm = device->device_data;
 988         mutex_lock(&register_mutex);
 989         err = snd_pcm_add(pcm);
 990         if (err) {
 991                 mutex_unlock(&register_mutex);
 992                 return err;
 993         }
 994         for (cidx = 0; cidx < 2; cidx++) {
 995                 int devtype = -1;
 996                 if (pcm->streams[cidx].substream == NULL)
 997                         continue;
 998                 switch (cidx) {
 999                 case SNDRV_PCM_STREAM_PLAYBACK:
1000                         sprintf(str, "pcmC%iD%ip", pcm->card->number, pcm->device);
1001                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1002                         break;
1003                 case SNDRV_PCM_STREAM_CAPTURE:
1004                         sprintf(str, "pcmC%iD%ic", pcm->card->number, pcm->device);
1005                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1006                         break;
1007                 }
1008                 /* device pointer to use, pcm->dev takes precedence if
1009                  * it is assigned, otherwise fall back to card's device
1010                  * if possible */
1011                 dev = pcm->dev;
1012                 if (!dev)
1013                         dev = snd_card_get_device_link(pcm->card);
1014                 /* register pcm */
1015                 err = snd_register_device_for_dev(devtype, pcm->card,
1016                                                   pcm->device,
1017                                                   &snd_pcm_f_ops[cidx],
1018                                                   pcm, str, dev);
1019                 if (err < 0) {
1020                         list_del(&pcm->list);
1021                         mutex_unlock(&register_mutex);
1022                         return err;
1023                 }
1024                 snd_add_device_sysfs_file(devtype, pcm->card, pcm->device,
1025                                           &pcm_attrs);
1026                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1027                         snd_pcm_timer_init(substream);
1028         }
1029
1030         list_for_each_entry(notify, &snd_pcm_notify_list, list)
1031                 notify->n_register(pcm);
1032
1033         mutex_unlock(&register_mutex);
1034         return 0;
1035 }
1036
1037 static int snd_pcm_dev_disconnect(struct snd_device *device)
1038 {
1039         struct snd_pcm *pcm = device->device_data;
1040         struct snd_pcm_notify *notify;
1041         struct snd_pcm_substream *substream;
1042         int cidx, devtype;
1043
1044         mutex_lock(&register_mutex);
1045         if (list_empty(&pcm->list))
1046                 goto unlock;
1047
1048         list_del_init(&pcm->list);
1049         for (cidx = 0; cidx < 2; cidx++)
1050                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1051                         if (substream->runtime)
1052                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1053         list_for_each_entry(notify, &snd_pcm_notify_list, list) {
1054                 notify->n_disconnect(pcm);
1055         }
1056         for (cidx = 0; cidx < 2; cidx++) {
1057                 devtype = -1;
1058                 switch (cidx) {
1059                 case SNDRV_PCM_STREAM_PLAYBACK:
1060                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1061                         break;
1062                 case SNDRV_PCM_STREAM_CAPTURE:
1063                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1064                         break;
1065                 }
1066                 snd_unregister_device(devtype, pcm->card, pcm->device);
1067         }
1068  unlock:
1069         mutex_unlock(&register_mutex);
1070         return 0;
1071 }
1072
1073 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1074 {
1075         struct snd_pcm *pcm;
1076
1077         if (snd_BUG_ON(!notify ||
1078                        !notify->n_register ||
1079                        !notify->n_unregister ||
1080                        !notify->n_disconnect))
1081                 return -EINVAL;
1082         mutex_lock(&register_mutex);
1083         if (nfree) {
1084                 list_del(&notify->list);
1085                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1086                         notify->n_unregister(pcm);
1087         } else {
1088                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1089                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1090                         notify->n_register(pcm);
1091         }
1092         mutex_unlock(&register_mutex);
1093         return 0;
1094 }
1095
1096 EXPORT_SYMBOL(snd_pcm_notify);
1097
1098 #ifdef CONFIG_PROC_FS
1099 /*
1100  *  Info interface
1101  */
1102
1103 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1104                               struct snd_info_buffer *buffer)
1105 {
1106         struct snd_pcm *pcm;
1107
1108         mutex_lock(&register_mutex);
1109         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1110                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1111                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1112                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1113                         snd_iprintf(buffer, " : playback %i",
1114                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1115                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1116                         snd_iprintf(buffer, " : capture %i",
1117                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1118                 snd_iprintf(buffer, "\n");
1119         }
1120         mutex_unlock(&register_mutex);
1121 }
1122
1123 static struct snd_info_entry *snd_pcm_proc_entry;
1124
1125 static void snd_pcm_proc_init(void)
1126 {
1127         struct snd_info_entry *entry;
1128
1129         if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
1130                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1131                 if (snd_info_register(entry) < 0) {
1132                         snd_info_free_entry(entry);
1133                         entry = NULL;
1134                 }
1135         }
1136         snd_pcm_proc_entry = entry;
1137 }
1138
1139 static void snd_pcm_proc_done(void)
1140 {
1141         snd_info_free_entry(snd_pcm_proc_entry);
1142 }
1143
1144 #else /* !CONFIG_PROC_FS */
1145 #define snd_pcm_proc_init()
1146 #define snd_pcm_proc_done()
1147 #endif /* CONFIG_PROC_FS */
1148
1149
1150 /*
1151  *  ENTRY functions
1152  */
1153
1154 static int __init alsa_pcm_init(void)
1155 {
1156         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1157         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1158         snd_pcm_proc_init();
1159         return 0;
1160 }
1161
1162 static void __exit alsa_pcm_exit(void)
1163 {
1164         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1165         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1166         snd_pcm_proc_done();
1167 }
1168
1169 module_init(alsa_pcm_init)
1170 module_exit(alsa_pcm_exit)