SAFE public projects git trees. - safe/jmp/linux-2.6/blob - sound/core/init.c

   1 /*
   2  *  Initialization routines
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
   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 <sound/driver.h>
  23 #include <linux/init.h>
  24 #include <linux/sched.h>
  25 #include <linux/file.h>
  26 #include <linux/slab.h>
  27 #include <linux/time.h>
  28 #include <linux/ctype.h>
  29 #include <linux/pci.h>
  30 #include <linux/pm.h>
  31
  32 #include <sound/core.h>
  33 #include <sound/control.h>
  34 #include <sound/info.h>
  35
  36 struct snd_shutdown_f_ops {
  37         struct file_operations f_ops;
  38         struct snd_shutdown_f_ops *next;
  39 };
  40
  41 unsigned int snd_cards_lock = 0;        /* locked for registering/using */
  42 struct snd_card *snd_cards[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = NULL};
  43 DEFINE_RWLOCK(snd_card_rwlock);
  44
  45 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  46 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
  47 #endif
  48
  49 static void snd_card_id_read(struct snd_info_entry *entry,
  50                              struct snd_info_buffer *buffer)
  51 {
  52         snd_iprintf(buffer, "%s\n", entry->card->id);
  53 }
  54
  55 static void snd_card_free_thread(void * __card);
  56
  57 /**
  58  *  snd_card_new - create and initialize a soundcard structure
  59  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
  60  *  @xid: card identification (ASCII string)
  61  *  @module: top level module for locking
  62  *  @extra_size: allocate this extra size after the main soundcard structure
  63  *
  64  *  Creates and initializes a soundcard structure.
  65  *
  66  *  Returns kmallocated snd_card structure. Creates the ALSA control interface
  67  *  (which is blocked until snd_card_register function is called).
  68  */
  69 struct snd_card *snd_card_new(int idx, const char *xid,
  70                          struct module *module, int extra_size)
  71 {
  72         struct snd_card *card;
  73         int err;
  74
  75         if (extra_size < 0)
  76                 extra_size = 0;
  77         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
  78         if (card == NULL)
  79                 return NULL;
  80         if (xid) {
  81                 if (!snd_info_check_reserved_words(xid))
  82                         goto __error;
  83                 strlcpy(card->id, xid, sizeof(card->id));
  84         }
  85         err = 0;
  86         write_lock(&snd_card_rwlock);
  87         if (idx < 0) {
  88                 int idx2;
  89                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
  90                         if (~snd_cards_lock & idx & 1<<idx2) {
  91                                 idx = idx2;
  92                                 if (idx >= snd_ecards_limit)
  93                                         snd_ecards_limit = idx + 1;
  94                                 break;
  95                         }
  96         } else if (idx < snd_ecards_limit) {
  97                 if (snd_cards_lock & (1 << idx))
  98                         err = -ENODEV;  /* invalid */
  99         } else if (idx < SNDRV_CARDS)
 100                 snd_ecards_limit = idx + 1; /* increase the limit */
 101         else
 102                 err = -ENODEV;
 103         if (idx < 0 || err < 0) {
 104                 write_unlock(&snd_card_rwlock);
 105                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
 106                 goto __error;
 107         }
 108         snd_cards_lock |= 1 << idx;             /* lock it */
 109         write_unlock(&snd_card_rwlock);
 110         card->number = idx;
 111         card->module = module;
 112         INIT_LIST_HEAD(&card->devices);
 113         init_rwsem(&card->controls_rwsem);
 114         rwlock_init(&card->ctl_files_rwlock);
 115         INIT_LIST_HEAD(&card->controls);
 116         INIT_LIST_HEAD(&card->ctl_files);
 117         spin_lock_init(&card->files_lock);
 118         init_waitqueue_head(&card->shutdown_sleep);
 119         INIT_WORK(&card->free_workq, snd_card_free_thread, card);
 120 #ifdef CONFIG_PM
 121         init_MUTEX(&card->power_lock);
 122         init_waitqueue_head(&card->power_sleep);
 123 #endif
 124         /* the control interface cannot be accessed from the user space until */
 125         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 126         if ((err = snd_ctl_create(card)) < 0) {
 127                 snd_printd("unable to register control minors\n");
 128                 goto __error;
 129         }
 130         if ((err = snd_info_card_create(card)) < 0) {
 131                 snd_printd("unable to create card info\n");
 132                 goto __error_ctl;
 133         }
 134         if (extra_size > 0)
 135                 card->private_data = (char *)card + sizeof(struct snd_card);
 136         return card;
 137
 138       __error_ctl:
 139         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 140       __error:
 141         kfree(card);
 142         return NULL;
 143 }
 144
 145 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 146 {
 147         return POLLERR | POLLNVAL;
 148 }
 149
 150 /**
 151  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 152  *  @card: soundcard structure
 153  *
 154  *  Disconnects all APIs from the file-operations (user space).
 155  *
 156  *  Returns zero, otherwise a negative error code.
 157  *
 158  *  Note: The current implementation replaces all active file->f_op with special
 159  *        dummy file operations (they do nothing except release).
 160  */
 161 int snd_card_disconnect(struct snd_card *card)
 162 {
 163         struct snd_monitor_file *mfile;
 164         struct file *file;
 165         struct snd_shutdown_f_ops *s_f_ops;
 166         struct file_operations *f_ops, *old_f_ops;
 167         int err;
 168
 169         spin_lock(&card->files_lock);
 170         if (card->shutdown) {
 171                 spin_unlock(&card->files_lock);
 172                 return 0;
 173         }
 174         card->shutdown = 1;
 175         spin_unlock(&card->files_lock);
 176
 177         /* phase 1: disable fops (user space) operations for ALSA API */
 178         write_lock(&snd_card_rwlock);
 179         snd_cards[card->number] = NULL;
 180         write_unlock(&snd_card_rwlock);
 181
 182         /* phase 2: replace file->f_op with special dummy operations */
 183
 184         spin_lock(&card->files_lock);
 185         mfile = card->files;
 186         while (mfile) {
 187                 file = mfile->file;
 188
 189                 /* it's critical part, use endless loop */
 190                 /* we have no room to fail */
 191                 s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
 192                 if (s_f_ops == NULL)
 193                         panic("Atomic allocation failed for snd_shutdown_f_ops!");
 194
 195                 f_ops = &s_f_ops->f_ops;
 196
 197                 memset(f_ops, 0, sizeof(*f_ops));
 198                 f_ops->owner = file->f_op->owner;
 199                 f_ops->release = file->f_op->release;
 200                 f_ops->poll = snd_disconnect_poll;
 201
 202                 s_f_ops->next = card->s_f_ops;
 203                 card->s_f_ops = s_f_ops;
 204
 205                 f_ops = fops_get(f_ops);
 206
 207                 old_f_ops = file->f_op;
 208                 file->f_op = f_ops;     /* must be atomic */
 209                 fops_put(old_f_ops);
 210
 211                 mfile = mfile->next;
 212         }
 213         spin_unlock(&card->files_lock);
 214
 215         /* phase 3: notify all connected devices about disconnection */
 216         /* at this point, they cannot respond to any calls except release() */
 217
 218 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 219         if (snd_mixer_oss_notify_callback)
 220                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 221 #endif
 222
 223         /* notify all devices that we are disconnected */
 224         err = snd_device_disconnect_all(card);
 225         if (err < 0)
 226                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 227
 228         return 0;
 229 }
 230
 231 /**
 232  *  snd_card_free - frees given soundcard structure
 233  *  @card: soundcard structure
 234  *
 235  *  This function releases the soundcard structure and the all assigned
 236  *  devices automatically.  That is, you don't have to release the devices
 237  *  by yourself.
 238  *
 239  *  Returns zero. Frees all associated devices and frees the control
 240  *  interface associated to given soundcard.
 241  */
 242 int snd_card_free(struct snd_card *card)
 243 {
 244         struct snd_shutdown_f_ops *s_f_ops;
 245
 246         if (card == NULL)
 247                 return -EINVAL;
 248         write_lock(&snd_card_rwlock);
 249         snd_cards[card->number] = NULL;
 250         write_unlock(&snd_card_rwlock);
 251
 252 #ifdef CONFIG_PM
 253         wake_up(&card->power_sleep);
 254 #endif
 255         /* wait, until all devices are ready for the free operation */
 256         wait_event(card->shutdown_sleep, card->files == NULL);
 257
 258 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 259         if (snd_mixer_oss_notify_callback)
 260                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 261 #endif
 262         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 263                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 264                 /* Fatal, but this situation should never occur */
 265         }
 266         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 267                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 268                 /* Fatal, but this situation should never occur */
 269         }
 270         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 271                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 272                 /* Fatal, but this situation should never occur */
 273         }
 274         if (card->private_free)
 275                 card->private_free(card);
 276         if (card->proc_id)
 277                 snd_info_unregister(card->proc_id);
 278         if (snd_info_card_free(card) < 0) {
 279                 snd_printk(KERN_WARNING "unable to free card info\n");
 280                 /* Not fatal error */
 281         }
 282         while (card->s_f_ops) {
 283                 s_f_ops = card->s_f_ops;
 284                 card->s_f_ops = s_f_ops->next;
 285                 kfree(s_f_ops);
 286         }
 287         write_lock(&snd_card_rwlock);
 288         snd_cards_lock &= ~(1 << card->number);
 289         write_unlock(&snd_card_rwlock);
 290         kfree(card);
 291         return 0;
 292 }
 293
 294 static void snd_card_free_thread(void * __card)
 295 {
 296         struct snd_card *card = __card;
 297         struct module * module = card->module;
 298
 299         if (!try_module_get(module)) {
 300                 snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
 301                 module = NULL;
 302         }
 303
 304         snd_card_free(card);
 305
 306         module_put(module);
 307 }
 308
 309 /**
 310  *  snd_card_free_in_thread - call snd_card_free() in thread
 311  *  @card: soundcard structure
 312  *
 313  *  This function schedules the call of snd_card_free() function in a
 314  *  work queue.  When all devices are released (non-busy), the work
 315  *  is woken up and calls snd_card_free().
 316  *
 317  *  When a card can be disconnected at any time by hotplug service,
 318  *  this function should be used in disconnect (or detach) callback
 319  *  instead of calling snd_card_free() directly.
 320  *
 321  *  Returns - zero otherwise a negative error code if the start of thread failed.
 322  */
 323 int snd_card_free_in_thread(struct snd_card *card)
 324 {
 325         if (card->files == NULL) {
 326                 snd_card_free(card);
 327                 return 0;
 328         }
 329
 330         if (schedule_work(&card->free_workq))
 331                 return 0;
 332
 333         snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
 334         /* try to free the structure immediately */
 335         snd_card_free(card);
 336         return -EFAULT;
 337 }
 338
 339 static void choose_default_id(struct snd_card *card)
 340 {
 341         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 342         char *id, *spos;
 343
 344         id = spos = card->shortname;
 345         while (*id != '\0') {
 346                 if (*id == ' ')
 347                         spos = id + 1;
 348                 id++;
 349         }
 350         id = card->id;
 351         while (*spos != '\0' && !isalnum(*spos))
 352                 spos++;
 353         if (isdigit(*spos))
 354                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 355         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 356                 if (isalnum(*spos))
 357                         *id++ = *spos;
 358                 spos++;
 359         }
 360         *id = '\0';
 361
 362         id = card->id;
 363
 364         if (*id == '\0')
 365                 strcpy(id, "default");
 366
 367         while (1) {
 368                 if (loops-- == 0) {
 369                         snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
 370                         strcpy(card->id, card->proc_root->name);
 371                         return;
 372                 }
 373                 if (!snd_info_check_reserved_words(id))
 374                         goto __change;
 375                 for (i = 0; i < snd_ecards_limit; i++) {
 376                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 377                                 goto __change;
 378                 }
 379                 break;
 380
 381               __change:
 382                 len = strlen(id);
 383                 if (idx_flag) {
 384                         if (id[len-1] != '9')
 385                                 id[len-1]++;
 386                         else
 387                                 id[len-1] = 'A';
 388                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 389                         strcat(id, "_1");
 390                         idx_flag++;
 391                 } else {
 392                         spos = id + len - 2;
 393                         if ((size_t)len <= sizeof(card->id) - 2)
 394                                 spos++;
 395                         *spos++ = '_';
 396                         *spos++ = '1';
 397                         *spos++ = '\0';
 398                         idx_flag++;
 399                 }
 400         }
 401 }
 402
 403 /**
 404  *  snd_card_register - register the soundcard
 405  *  @card: soundcard structure
 406  *
 407  *  This function registers all the devices assigned to the soundcard.
 408  *  Until calling this, the ALSA control interface is blocked from the
 409  *  external accesses.  Thus, you should call this function at the end
 410  *  of the initialization of the card.
 411  *
 412  *  Returns zero otherwise a negative error code if the registrain failed.
 413  */
 414 int snd_card_register(struct snd_card *card)
 415 {
 416         int err;
 417         struct snd_info_entry *entry;
 418
 419         snd_assert(card != NULL, return -EINVAL);
 420         if ((err = snd_device_register_all(card)) < 0)
 421                 return err;
 422         write_lock(&snd_card_rwlock);
 423         if (snd_cards[card->number]) {
 424                 /* already registered */
 425                 write_unlock(&snd_card_rwlock);
 426                 return 0;
 427         }
 428         if (card->id[0] == '\0')
 429                 choose_default_id(card);
 430         snd_cards[card->number] = card;
 431         write_unlock(&snd_card_rwlock);
 432         if ((err = snd_info_card_register(card)) < 0) {
 433                 snd_printd("unable to create card info\n");
 434                 goto __skip_info;
 435         }
 436         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 437                 snd_printd("unable to create card entry\n");
 438                 goto __skip_info;
 439         }
 440         entry->c.text.read_size = PAGE_SIZE;
 441         entry->c.text.read = snd_card_id_read;
 442         if (snd_info_register(entry) < 0) {
 443                 snd_info_free_entry(entry);
 444                 entry = NULL;
 445         }
 446         card->proc_id = entry;
 447       __skip_info:
 448 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 449         if (snd_mixer_oss_notify_callback)
 450                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 451 #endif
 452         return 0;
 453 }
 454
 455 static struct snd_info_entry *snd_card_info_entry = NULL;
 456
 457 static void snd_card_info_read(struct snd_info_entry *entry,
 458                                struct snd_info_buffer *buffer)
 459 {
 460         int idx, count;
 461         struct snd_card *card;
 462
 463         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 464                 read_lock(&snd_card_rwlock);
 465                 if ((card = snd_cards[idx]) != NULL) {
 466                         count++;
 467                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 468                                         idx,
 469                                         card->id,
 470                                         card->driver,
 471                                         card->shortname);
 472                         snd_iprintf(buffer, "                      %s\n",
 473                                         card->longname);
 474                 }
 475                 read_unlock(&snd_card_rwlock);
 476         }
 477         if (!count)
 478                 snd_iprintf(buffer, "--- no soundcards ---\n");
 479 }
 480
 481 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
 482
 483 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 484 {
 485         int idx, count;
 486         struct snd_card *card;
 487
 488         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 489                 read_lock(&snd_card_rwlock);
 490                 if ((card = snd_cards[idx]) != NULL) {
 491                         count++;
 492                         snd_iprintf(buffer, "%s\n", card->longname);
 493                 }
 494                 read_unlock(&snd_card_rwlock);
 495         }
 496         if (!count) {
 497                 snd_iprintf(buffer, "--- no soundcards ---\n");
 498         }
 499 }
 500
 501 #endif
 502
 503 #ifdef MODULE
 504 static struct snd_info_entry *snd_card_module_info_entry;
 505 static void snd_card_module_info_read(struct snd_info_entry *entry,
 506                                       struct snd_info_buffer *buffer)
 507 {
 508         int idx;
 509         struct snd_card *card;
 510
 511         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 512                 read_lock(&snd_card_rwlock);
 513                 if ((card = snd_cards[idx]) != NULL)
 514                         snd_iprintf(buffer, "%2i %s\n",
 515                                     idx, card->module->name);
 516                 read_unlock(&snd_card_rwlock);
 517         }
 518 }
 519 #endif
 520
 521 int __init snd_card_info_init(void)
 522 {
 523         struct snd_info_entry *entry;
 524
 525         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 526         if (! entry)
 527                 return -ENOMEM;
 528         entry->c.text.read_size = PAGE_SIZE;
 529         entry->c.text.read = snd_card_info_read;
 530         if (snd_info_register(entry) < 0) {
 531                 snd_info_free_entry(entry);
 532                 return -ENOMEM;
 533         }
 534         snd_card_info_entry = entry;
 535
 536 #ifdef MODULE
 537         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 538         if (entry) {
 539                 entry->c.text.read_size = PAGE_SIZE;
 540                 entry->c.text.read = snd_card_module_info_read;
 541                 if (snd_info_register(entry) < 0)
 542                         snd_info_free_entry(entry);
 543                 else
 544                         snd_card_module_info_entry = entry;
 545         }
 546 #endif
 547
 548         return 0;
 549 }
 550
 551 int __exit snd_card_info_done(void)
 552 {
 553         if (snd_card_info_entry)
 554                 snd_info_unregister(snd_card_info_entry);
 555 #ifdef MODULE
 556         if (snd_card_module_info_entry)
 557                 snd_info_unregister(snd_card_module_info_entry);
 558 #endif
 559         return 0;
 560 }
 561
 562 /**
 563  *  snd_component_add - add a component string
 564  *  @card: soundcard structure
 565  *  @component: the component id string
 566  *
 567  *  This function adds the component id string to the supported list.
 568  *  The component can be referred from the alsa-lib.
 569  *
 570  *  Returns zero otherwise a negative error code.
 571  */
 572
 573 int snd_component_add(struct snd_card *card, const char *component)
 574 {
 575         char *ptr;
 576         int len = strlen(component);
 577
 578         ptr = strstr(card->components, component);
 579         if (ptr != NULL) {
 580                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 581                         return 1;
 582         }
 583         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 584                 snd_BUG();
 585                 return -ENOMEM;
 586         }
 587         if (card->components[0] != '\0')
 588                 strcat(card->components, " ");
 589         strcat(card->components, component);
 590         return 0;
 591 }
 592
 593 /**
 594  *  snd_card_file_add - add the file to the file list of the card
 595  *  @card: soundcard structure
 596  *  @file: file pointer
 597  *
 598  *  This function adds the file to the file linked-list of the card.
 599  *  This linked-list is used to keep tracking the connection state,
 600  *  and to avoid the release of busy resources by hotplug.
 601  *
 602  *  Returns zero or a negative error code.
 603  */
 604 int snd_card_file_add(struct snd_card *card, struct file *file)
 605 {
 606         struct snd_monitor_file *mfile;
 607
 608         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 609         if (mfile == NULL)
 610                 return -ENOMEM;
 611         mfile->file = file;
 612         mfile->next = NULL;
 613         spin_lock(&card->files_lock);
 614         if (card->shutdown) {
 615                 spin_unlock(&card->files_lock);
 616                 kfree(mfile);
 617                 return -ENODEV;
 618         }
 619         mfile->next = card->files;
 620         card->files = mfile;
 621         spin_unlock(&card->files_lock);
 622         return 0;
 623 }
 624
 625 /**
 626  *  snd_card_file_remove - remove the file from the file list
 627  *  @card: soundcard structure
 628  *  @file: file pointer
 629  *
 630  *  This function removes the file formerly added to the card via
 631  *  snd_card_file_add() function.
 632  *  If all files are removed and the release of the card is
 633  *  scheduled, it will wake up the the thread to call snd_card_free()
 634  *  (see snd_card_free_in_thread() function).
 635  *
 636  *  Returns zero or a negative error code.
 637  */
 638 int snd_card_file_remove(struct snd_card *card, struct file *file)
 639 {
 640         struct snd_monitor_file *mfile, *pfile = NULL;
 641
 642         spin_lock(&card->files_lock);
 643         mfile = card->files;
 644         while (mfile) {
 645                 if (mfile->file == file) {
 646                         if (pfile)
 647                                 pfile->next = mfile->next;
 648                         else
 649                                 card->files = mfile->next;
 650                         break;
 651                 }
 652                 pfile = mfile;
 653                 mfile = mfile->next;
 654         }
 655         spin_unlock(&card->files_lock);
 656         if (card->files == NULL)
 657                 wake_up(&card->shutdown_sleep);
 658         if (!mfile) {
 659                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 660                 return -ENOENT;
 661         }
 662         kfree(mfile);
 663         return 0;
 664 }
 665
 666 #ifdef CONFIG_PM
 667 /**
 668  *  snd_power_wait - wait until the power-state is changed.
 669  *  @card: soundcard structure
 670  *  @power_state: expected power state
 671  *  @file: file structure for the O_NONBLOCK check (optional)
 672  *
 673  *  Waits until the power-state is changed.
 674  *
 675  *  Note: the power lock must be active before call.
 676  */
 677 int snd_power_wait(struct snd_card *card, unsigned int power_state, struct file *file)
 678 {
 679         wait_queue_t wait;
 680         int result = 0;
 681
 682         /* fastpath */
 683         if (snd_power_get_state(card) == power_state)
 684                 return 0;
 685         init_waitqueue_entry(&wait, current);
 686         add_wait_queue(&card->power_sleep, &wait);
 687         while (1) {
 688                 if (card->shutdown) {
 689                         result = -ENODEV;
 690                         break;
 691                 }
 692                 if (snd_power_get_state(card) == power_state)
 693                         break;
 694 #if 0 /* block all devices */
 695                 if (file && (file->f_flags & O_NONBLOCK)) {
 696                         result = -EAGAIN;
 697                         break;
 698                 }
 699 #endif
 700                 set_current_state(TASK_UNINTERRUPTIBLE);
 701                 snd_power_unlock(card);
 702                 schedule_timeout(30 * HZ);
 703                 snd_power_lock(card);
 704         }
 705         remove_wait_queue(&card->power_sleep, &wait);
 706         return result;
 707 }
 708
 709 #endif /* CONFIG_PM */