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 <sound/core.h>
  30 #include <sound/control.h>
  31 #include <sound/info.h>
  32
  33 struct snd_shutdown_f_ops {
  34         struct file_operations f_ops;
  35         struct snd_shutdown_f_ops *next;
  36 };
  37
  38 int snd_cards_count = 0;
  39 unsigned int snd_cards_lock = 0;        /* locked for registering/using */
  40 snd_card_t *snd_cards[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = NULL};
  41 rwlock_t snd_card_rwlock = RW_LOCK_UNLOCKED;
  42
  43 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  44 int (*snd_mixer_oss_notify_callback)(snd_card_t *card, int free_flag);
  45 #endif
  46
  47 static void snd_card_id_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
  48 {
  49         snd_iprintf(buffer, "%s\n", entry->card->id);
  50 }
  51
  52 static void snd_card_free_thread(void * __card);
  53
  54 /**
  55  *  snd_card_new - create and initialize a soundcard structure
  56  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
  57  *  @xid: card identification (ASCII string)
  58  *  @module: top level module for locking
  59  *  @extra_size: allocate this extra size after the main soundcard structure
  60  *
  61  *  Creates and initializes a soundcard structure.
  62  *
  63  *  Returns kmallocated snd_card_t structure. Creates the ALSA control interface
  64  *  (which is blocked until snd_card_register function is called).
  65  */
  66 snd_card_t *snd_card_new(int idx, const char *xid,
  67                          struct module *module, int extra_size)
  68 {
  69         snd_card_t *card;
  70         int err;
  71
  72         if (extra_size < 0)
  73                 extra_size = 0;
  74         card = (snd_card_t *) snd_kcalloc(sizeof(snd_card_t) + extra_size, GFP_KERNEL);
  75         if (card == NULL)
  76                 return NULL;
  77         if (xid) {
  78                 if (!snd_info_check_reserved_words(xid))
  79                         goto __error;
  80                 strlcpy(card->id, xid, sizeof(card->id));
  81         }
  82         err = 0;
  83         write_lock(&snd_card_rwlock);
  84         if (idx < 0) {
  85                 int idx2;
  86                 for (idx2 = 0; idx2 < snd_ecards_limit; idx2++)
  87                         if (!(snd_cards_lock & (1 << idx2))) {
  88                                 idx = idx2;
  89                                 break;
  90                         }
  91                 if (idx < 0 && snd_ecards_limit < SNDRV_CARDS)
  92                         /* for dynamically additional devices like hotplug:
  93                          * increment the limit if still free slot exists.
  94                          */
  95                         idx = snd_ecards_limit++;
  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_register(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(snd_card_t);
 136         return card;
 137
 138       __error_ctl:
 139         snd_ctl_unregister(card);
 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(snd_card_t * 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         snd_ctl_disconnect(card);
 219
 220 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 221         if (snd_mixer_oss_notify_callback)
 222                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 223 #endif
 224
 225         /* notify all devices that we are disconnected */
 226         err = snd_device_disconnect_all(card);
 227         if (err < 0)
 228                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 229
 230         return 0;
 231 }
 232
 233 /**
 234  *  snd_card_free - frees given soundcard structure
 235  *  @card: soundcard structure
 236  *
 237  *  This function releases the soundcard structure and the all assigned
 238  *  devices automatically.  That is, you don't have to release the devices
 239  *  by yourself.
 240  *
 241  *  Returns zero. Frees all associated devices and frees the control
 242  *  interface associated to given soundcard.
 243  */
 244 int snd_card_free(snd_card_t * card)
 245 {
 246         struct snd_shutdown_f_ops *s_f_ops;
 247
 248         if (card == NULL)
 249                 return -EINVAL;
 250         write_lock(&snd_card_rwlock);
 251         snd_cards[card->number] = NULL;
 252         snd_cards_count--;
 253         write_unlock(&snd_card_rwlock);
 254
 255 #ifdef CONFIG_PM
 256         wake_up(&card->power_sleep);
 257 #endif
 258
 259         /* wait, until all devices are ready for the free operation */
 260         wait_event(card->shutdown_sleep, card->files == NULL);
 261
 262 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 263         if (snd_mixer_oss_notify_callback)
 264                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 265 #endif
 266         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 267                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 268                 /* Fatal, but this situation should never occur */
 269         }
 270         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 271                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 272                 /* Fatal, but this situation should never occur */
 273         }
 274         if (snd_ctl_unregister(card) < 0) {
 275                 snd_printk(KERN_ERR "unable to unregister control minors\n");
 276                 /* Not fatal error */
 277         }
 278         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 279                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 280                 /* Fatal, but this situation should never occur */
 281         }
 282         if (card->private_free)
 283                 card->private_free(card);
 284         if (card->proc_id)
 285                 snd_info_unregister(card->proc_id);
 286         if (snd_info_card_free(card) < 0) {
 287                 snd_printk(KERN_WARNING "unable to free card info\n");
 288                 /* Not fatal error */
 289         }
 290         while (card->s_f_ops) {
 291                 s_f_ops = card->s_f_ops;
 292                 card->s_f_ops = s_f_ops->next;
 293                 kfree(s_f_ops);
 294         }
 295         write_lock(&snd_card_rwlock);
 296         snd_cards_lock &= ~(1 << card->number);
 297         write_unlock(&snd_card_rwlock);
 298         kfree(card);
 299         return 0;
 300 }
 301
 302 static void snd_card_free_thread(void * __card)
 303 {
 304         snd_card_t *card = __card;
 305         struct module * module = card->module;
 306
 307         if (!try_module_get(module)) {
 308                 snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
 309                 module = NULL;
 310         }
 311
 312         snd_card_free(card);
 313
 314         module_put(module);
 315 }
 316
 317 /**
 318  *  snd_card_free_in_thread - call snd_card_free() in thread
 319  *  @card: soundcard structure
 320  *
 321  *  This function schedules the call of snd_card_free() function in a
 322  *  work queue.  When all devices are released (non-busy), the work
 323  *  is woken up and calls snd_card_free().
 324  *
 325  *  When a card can be disconnected at any time by hotplug service,
 326  *  this function should be used in disconnect (or detach) callback
 327  *  instead of calling snd_card_free() directly.
 328  *
 329  *  Returns - zero otherwise a negative error code if the start of thread failed.
 330  */
 331 int snd_card_free_in_thread(snd_card_t * card)
 332 {
 333         if (card->files == NULL) {
 334                 snd_card_free(card);
 335                 return 0;
 336         }
 337
 338         if (schedule_work(&card->free_workq))
 339                 return 0;
 340
 341         snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
 342         /* try to free the structure immediately */
 343         snd_card_free(card);
 344         return -EFAULT;
 345 }
 346
 347 static void choose_default_id(snd_card_t * card)
 348 {
 349         int i, len, idx_flag = 0, loops = 8;
 350         char *id, *spos;
 351
 352         id = spos = card->shortname;
 353         while (*id != '\0') {
 354                 if (*id == ' ')
 355                         spos = id + 1;
 356                 id++;
 357         }
 358         id = card->id;
 359         while (*spos != '\0' && !isalnum(*spos))
 360                 spos++;
 361         if (isdigit(*spos))
 362                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 363         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 364                 if (isalnum(*spos))
 365                         *id++ = *spos;
 366                 spos++;
 367         }
 368         *id = '\0';
 369
 370         id = card->id;
 371
 372         if (*id == '\0')
 373                 strcpy(id, "default");
 374
 375         while (1) {
 376                 if (loops-- == 0) {
 377                         snd_printk(KERN_ERR "unable to choose default card id (%s)", id);
 378                         strcpy(card->id, card->proc_root->name);
 379                         return;
 380                 }
 381                 if (!snd_info_check_reserved_words(id))
 382                         goto __change;
 383                 for (i = 0; i < snd_ecards_limit; i++) {
 384                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 385                                 goto __change;
 386                 }
 387                 break;
 388
 389               __change:
 390                 len = strlen(id);
 391                 if (idx_flag)
 392                         id[len-1]++;
 393                 else if ((size_t)len <= sizeof(card->id) - 3) {
 394                         strcat(id, "_1");
 395                         idx_flag++;
 396                 } else {
 397                         spos = id + len - 2;
 398                         if ((size_t)len <= sizeof(card->id) - 2)
 399                                 spos++;
 400                         *spos++ = '_';
 401                         *spos++ = '1';
 402                         *spos++ = '\0';
 403                         idx_flag++;
 404                 }
 405         }
 406 }
 407
 408 /**
 409  *  snd_card_register - register the soundcard
 410  *  @card: soundcard structure
 411  *
 412  *  This function registers all the devices assigned to the soundcard.
 413  *  Until calling this, the ALSA control interface is blocked from the
 414  *  external accesses.  Thus, you should call this function at the end
 415  *  of the initialization of the card.
 416  *
 417  *  Returns zero otherwise a negative error code if the registrain failed.
 418  */
 419 int snd_card_register(snd_card_t * card)
 420 {
 421         int err;
 422         snd_info_entry_t *entry;
 423
 424         snd_runtime_check(card != NULL, return -EINVAL);
 425         if ((err = snd_device_register_all(card)) < 0)
 426                 return err;
 427         write_lock(&snd_card_rwlock);
 428         if (snd_cards[card->number]) {
 429                 /* already registered */
 430                 write_unlock(&snd_card_rwlock);
 431                 return 0;
 432         }
 433         if (card->id[0] == '\0')
 434                 choose_default_id(card);
 435         snd_cards[card->number] = card;
 436         snd_cards_count++;
 437         write_unlock(&snd_card_rwlock);
 438         if ((err = snd_info_card_register(card)) < 0) {
 439                 snd_printd("unable to create card info\n");
 440                 goto __skip_info;
 441         }
 442         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 443                 snd_printd("unable to create card entry\n");
 444                 goto __skip_info;
 445         }
 446         entry->c.text.read_size = PAGE_SIZE;
 447         entry->c.text.read = snd_card_id_read;
 448         if (snd_info_register(entry) < 0) {
 449                 snd_info_free_entry(entry);
 450                 entry = NULL;
 451         }
 452         card->proc_id = entry;
 453       __skip_info:
 454 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 455         if (snd_mixer_oss_notify_callback)
 456                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 457 #endif
 458         return 0;
 459 }
 460
 461 static snd_info_entry_t *snd_card_info_entry = NULL;
 462
 463 static void snd_card_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 464 {
 465         int idx, count;
 466         snd_card_t *card;
 467
 468         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 469                 read_lock(&snd_card_rwlock);
 470                 if ((card = snd_cards[idx]) != NULL) {
 471                         count++;
 472                         snd_iprintf(buffer, "%i [%-15s]: %s - %s\n",
 473                                         idx,
 474                                         card->id,
 475                                         card->driver,
 476                                         card->shortname);
 477                         snd_iprintf(buffer, "                     %s\n",
 478                                         card->longname);
 479                 }
 480                 read_unlock(&snd_card_rwlock);
 481         }
 482         if (!count)
 483                 snd_iprintf(buffer, "--- no soundcards ---\n");
 484 }
 485
 486 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
 487
 488 void snd_card_info_read_oss(snd_info_buffer_t * buffer)
 489 {
 490         int idx, count;
 491         snd_card_t *card;
 492
 493         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 494                 read_lock(&snd_card_rwlock);
 495                 if ((card = snd_cards[idx]) != NULL) {
 496                         count++;
 497                         snd_iprintf(buffer, "%s\n", card->longname);
 498                 }
 499                 read_unlock(&snd_card_rwlock);
 500         }
 501         if (!count) {
 502                 snd_iprintf(buffer, "--- no soundcards ---\n");
 503         }
 504 }
 505
 506 #endif
 507
 508 #ifdef MODULE
 509 static snd_info_entry_t *snd_card_module_info_entry;
 510 static void snd_card_module_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 511 {
 512         int idx;
 513         snd_card_t *card;
 514
 515         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 516                 read_lock(&snd_card_rwlock);
 517                 if ((card = snd_cards[idx]) != NULL)
 518                         snd_iprintf(buffer, "%i %s\n", idx, card->module->name);
 519                 read_unlock(&snd_card_rwlock);
 520         }
 521 }
 522 #endif
 523
 524 int __init snd_card_info_init(void)
 525 {
 526         snd_info_entry_t *entry;
 527
 528         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 529         snd_runtime_check(entry != NULL, return -ENOMEM);
 530         entry->c.text.read_size = PAGE_SIZE;
 531         entry->c.text.read = snd_card_info_read;
 532         if (snd_info_register(entry) < 0) {
 533                 snd_info_free_entry(entry);
 534                 return -ENOMEM;
 535         }
 536         snd_card_info_entry = entry;
 537
 538 #ifdef MODULE
 539         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 540         if (entry) {
 541                 entry->c.text.read_size = PAGE_SIZE;
 542                 entry->c.text.read = snd_card_module_info_read;
 543                 if (snd_info_register(entry) < 0)
 544                         snd_info_free_entry(entry);
 545                 else
 546                         snd_card_module_info_entry = entry;
 547         }
 548 #endif
 549
 550         return 0;
 551 }
 552
 553 int __exit snd_card_info_done(void)
 554 {
 555         if (snd_card_info_entry)
 556                 snd_info_unregister(snd_card_info_entry);
 557 #ifdef MODULE
 558         if (snd_card_module_info_entry)
 559                 snd_info_unregister(snd_card_module_info_entry);
 560 #endif
 561         return 0;
 562 }
 563
 564 /**
 565  *  snd_component_add - add a component string
 566  *  @card: soundcard structure
 567  *  @component: the component id string
 568  *
 569  *  This function adds the component id string to the supported list.
 570  *  The component can be referred from the alsa-lib.
 571  *
 572  *  Returns zero otherwise a negative error code.
 573  */
 574
 575 int snd_component_add(snd_card_t *card, const char *component)
 576 {
 577         char *ptr;
 578         int len = strlen(component);
 579
 580         ptr = strstr(card->components, component);
 581         if (ptr != NULL) {
 582                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 583                         return 1;
 584         }
 585         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 586                 snd_BUG();
 587                 return -ENOMEM;
 588         }
 589         if (card->components[0] != '\0')
 590                 strcat(card->components, " ");
 591         strcat(card->components, component);
 592         return 0;
 593 }
 594
 595 /**
 596  *  snd_card_file_add - add the file to the file list of the card
 597  *  @card: soundcard structure
 598  *  @file: file pointer
 599  *
 600  *  This function adds the file to the file linked-list of the card.
 601  *  This linked-list is used to keep tracking the connection state,
 602  *  and to avoid the release of busy resources by hotplug.
 603  *
 604  *  Returns zero or a negative error code.
 605  */
 606 int snd_card_file_add(snd_card_t *card, struct file *file)
 607 {
 608         struct snd_monitor_file *mfile;
 609
 610         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 611         if (mfile == NULL)
 612                 return -ENOMEM;
 613         mfile->file = file;
 614         mfile->next = NULL;
 615         spin_lock(&card->files_lock);
 616         if (card->shutdown) {
 617                 spin_unlock(&card->files_lock);
 618                 kfree(mfile);
 619                 return -ENODEV;
 620         }
 621         mfile->next = card->files;
 622         card->files = mfile;
 623         spin_unlock(&card->files_lock);
 624         return 0;
 625 }
 626
 627 /**
 628  *  snd_card_file_remove - remove the file from the file list
 629  *  @card: soundcard structure
 630  *  @file: file pointer
 631  *
 632  *  This function removes the file formerly added to the card via
 633  *  snd_card_file_add() function.
 634  *  If all files are removed and the release of the card is
 635  *  scheduled, it will wake up the the thread to call snd_card_free()
 636  *  (see snd_card_free_in_thread() function).
 637  *
 638  *  Returns zero or a negative error code.
 639  */
 640 int snd_card_file_remove(snd_card_t *card, struct file *file)
 641 {
 642         struct snd_monitor_file *mfile, *pfile = NULL;
 643
 644         spin_lock(&card->files_lock);
 645         mfile = card->files;
 646         while (mfile) {
 647                 if (mfile->file == file) {
 648                         if (pfile)
 649                                 pfile->next = mfile->next;
 650                         else
 651                                 card->files = mfile->next;
 652                         break;
 653                 }
 654                 pfile = mfile;
 655                 mfile = mfile->next;
 656         }
 657         spin_unlock(&card->files_lock);
 658         if (card->files == NULL)
 659                 wake_up(&card->shutdown_sleep);
 660         if (mfile) {
 661                 kfree(mfile);
 662         } else {
 663                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 664                 return -ENOENT;
 665         }
 666         return 0;
 667 }
 668
 669 #ifdef CONFIG_PM
 670 /**
 671  *  snd_power_wait - wait until the power-state is changed.
 672  *  @card: soundcard structure
 673  *  @power_state: expected power state
 674  *  @file: file structure for the O_NONBLOCK check (optional)
 675  *
 676  *  Waits until the power-state is changed.
 677  *
 678  *  Note: the power lock must be active before call.
 679  */
 680 int snd_power_wait(snd_card_t *card, unsigned int power_state, struct file *file)
 681 {
 682         wait_queue_t wait;
 683         int result = 0;
 684
 685         /* fastpath */
 686         if (snd_power_get_state(card) == power_state)
 687                 return 0;
 688         init_waitqueue_entry(&wait, current);
 689         add_wait_queue(&card->power_sleep, &wait);
 690         while (1) {
 691                 if (card->shutdown) {
 692                         result = -ENODEV;
 693                         break;
 694                 }
 695                 if (snd_power_get_state(card) == power_state)
 696                         break;
 697 #if 0 /* block all devices */
 698                 if (file && (file->f_flags & O_NONBLOCK)) {
 699                         result = -EAGAIN;
 700                         break;
 701                 }
 702 #endif
 703                 set_current_state(TASK_UNINTERRUPTIBLE);
 704                 snd_power_unlock(card);
 705                 schedule_timeout(30 * HZ);
 706                 snd_power_lock(card);
 707         }
 708         remove_wait_queue(&card->power_sleep, &wait);
 709         return result;
 710 }
 711 #endif /* CONFIG_PM */