ad68761abba1a86eb9dd9fa16d0c495ecb428d84
[linux-2.6.git] / 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 #ifdef CONFIG_PROC_FS
50 static void snd_card_id_read(struct snd_info_entry *entry,
51                              struct snd_info_buffer *buffer)
52 {
53         snd_iprintf(buffer, "%s\n", entry->card->id);
54 }
55
56 static inline int init_info_for_card(struct snd_card *card)
57 {
58         int err;
59         struct snd_info_entry *entry;
60
61         if ((err = snd_info_card_register(card)) < 0) {
62                 snd_printd("unable to create card info\n");
63                 return err;
64         }
65         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
66                 snd_printd("unable to create card entry\n");
67                 return err;
68         }
69         entry->c.text.read_size = PAGE_SIZE;
70         entry->c.text.read = snd_card_id_read;
71         if (snd_info_register(entry) < 0) {
72                 snd_info_free_entry(entry);
73                 entry = NULL;
74         }
75         card->proc_id = entry;
76         return 0;
77 }
78 #else /* !CONFIG_PROC_FS */
79 #define init_info_for_card(card)
80 #endif
81
82 static void snd_card_free_thread(void * __card);
83
84 /**
85  *  snd_card_new - create and initialize a soundcard structure
86  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
87  *  @xid: card identification (ASCII string)
88  *  @module: top level module for locking
89  *  @extra_size: allocate this extra size after the main soundcard structure
90  *
91  *  Creates and initializes a soundcard structure.
92  *
93  *  Returns kmallocated snd_card structure. Creates the ALSA control interface
94  *  (which is blocked until snd_card_register function is called).
95  */
96 struct snd_card *snd_card_new(int idx, const char *xid,
97                          struct module *module, int extra_size)
98 {
99         struct snd_card *card;
100         int err;
101
102         if (extra_size < 0)
103                 extra_size = 0;
104         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
105         if (card == NULL)
106                 return NULL;
107         if (xid) {
108                 if (!snd_info_check_reserved_words(xid))
109                         goto __error;
110                 strlcpy(card->id, xid, sizeof(card->id));
111         }
112         err = 0;
113         write_lock(&snd_card_rwlock);
114         if (idx < 0) {
115                 int idx2;
116                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
117                         if (~snd_cards_lock & idx & 1<<idx2) {
118                                 idx = idx2;
119                                 if (idx >= snd_ecards_limit)
120                                         snd_ecards_limit = idx + 1;
121                                 break;
122                         }
123         } else if (idx < snd_ecards_limit) {
124                 if (snd_cards_lock & (1 << idx))
125                         err = -ENODEV;  /* invalid */
126         } else if (idx < SNDRV_CARDS)
127                 snd_ecards_limit = idx + 1; /* increase the limit */
128         else
129                 err = -ENODEV;
130         if (idx < 0 || err < 0) {
131                 write_unlock(&snd_card_rwlock);
132                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
133                 goto __error;
134         }
135         snd_cards_lock |= 1 << idx;             /* lock it */
136         write_unlock(&snd_card_rwlock);
137         card->number = idx;
138         card->module = module;
139         INIT_LIST_HEAD(&card->devices);
140         init_rwsem(&card->controls_rwsem);
141         rwlock_init(&card->ctl_files_rwlock);
142         INIT_LIST_HEAD(&card->controls);
143         INIT_LIST_HEAD(&card->ctl_files);
144         spin_lock_init(&card->files_lock);
145         init_waitqueue_head(&card->shutdown_sleep);
146         INIT_WORK(&card->free_workq, snd_card_free_thread, card);
147 #ifdef CONFIG_PM
148         mutex_init(&card->power_lock);
149         init_waitqueue_head(&card->power_sleep);
150 #endif
151         /* the control interface cannot be accessed from the user space until */
152         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
153         if ((err = snd_ctl_create(card)) < 0) {
154                 snd_printd("unable to register control minors\n");
155                 goto __error;
156         }
157         if ((err = snd_info_card_create(card)) < 0) {
158                 snd_printd("unable to create card info\n");
159                 goto __error_ctl;
160         }
161         if (extra_size > 0)
162                 card->private_data = (char *)card + sizeof(struct snd_card);
163         return card;
164
165       __error_ctl:
166         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
167       __error:
168         kfree(card);
169         return NULL;
170 }
171
172 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
173 {
174         return -ENODEV;
175 }
176
177 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
178                                    size_t count, loff_t *offset)
179 {
180         return -ENODEV;
181 }
182
183 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
184                                     size_t count, loff_t *offset)
185 {
186         return -ENODEV;
187 }
188
189 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
190 {
191         return POLLERR | POLLNVAL;
192 }
193
194 static long snd_disconnect_ioctl(struct file *file,
195                                  unsigned int cmd, unsigned long arg)
196 {
197         return -ENODEV;
198 }
199
200 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
201 {
202         return -ENODEV;
203 }
204
205 static int snd_disconnect_fasync(int fd, struct file *file, int on)
206 {
207         return -ENODEV;
208 }
209
210 /**
211  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
212  *  @card: soundcard structure
213  *
214  *  Disconnects all APIs from the file-operations (user space).
215  *
216  *  Returns zero, otherwise a negative error code.
217  *
218  *  Note: The current implementation replaces all active file->f_op with special
219  *        dummy file operations (they do nothing except release).
220  */
221 int snd_card_disconnect(struct snd_card *card)
222 {
223         struct snd_monitor_file *mfile;
224         struct file *file;
225         struct snd_shutdown_f_ops *s_f_ops;
226         struct file_operations *f_ops, *old_f_ops;
227         int err;
228
229         spin_lock(&card->files_lock);
230         if (card->shutdown) {
231                 spin_unlock(&card->files_lock);
232                 return 0;
233         }
234         card->shutdown = 1;
235         spin_unlock(&card->files_lock);
236
237         /* phase 1: disable fops (user space) operations for ALSA API */
238         write_lock(&snd_card_rwlock);
239         snd_cards[card->number] = NULL;
240         write_unlock(&snd_card_rwlock);
241         
242         /* phase 2: replace file->f_op with special dummy operations */
243         
244         spin_lock(&card->files_lock);
245         mfile = card->files;
246         while (mfile) {
247                 file = mfile->file;
248
249                 /* it's critical part, use endless loop */
250                 /* we have no room to fail */
251                 s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
252                 if (s_f_ops == NULL)
253                         panic("Atomic allocation failed for snd_shutdown_f_ops!");
254
255                 f_ops = &s_f_ops->f_ops;
256
257                 memset(f_ops, 0, sizeof(*f_ops));
258                 f_ops->owner = file->f_op->owner;
259                 f_ops->release = file->f_op->release;
260                 f_ops->llseek = snd_disconnect_llseek;
261                 f_ops->read = snd_disconnect_read;
262                 f_ops->write = snd_disconnect_write;
263                 f_ops->poll = snd_disconnect_poll;
264                 f_ops->unlocked_ioctl = snd_disconnect_ioctl;
265 #ifdef CONFIG_COMPAT
266                 f_ops->compat_ioctl = snd_disconnect_ioctl;
267 #endif
268                 f_ops->mmap = snd_disconnect_mmap;
269                 f_ops->fasync = snd_disconnect_fasync;
270
271                 s_f_ops->next = card->s_f_ops;
272                 card->s_f_ops = s_f_ops;
273                 
274                 f_ops = fops_get(f_ops);
275
276                 old_f_ops = file->f_op;
277                 file->f_op = f_ops;     /* must be atomic */
278                 fops_put(old_f_ops);
279                 
280                 mfile = mfile->next;
281         }
282         spin_unlock(&card->files_lock); 
283
284         /* phase 3: notify all connected devices about disconnection */
285         /* at this point, they cannot respond to any calls except release() */
286
287 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
288         if (snd_mixer_oss_notify_callback)
289                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
290 #endif
291
292         /* notify all devices that we are disconnected */
293         err = snd_device_disconnect_all(card);
294         if (err < 0)
295                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
296
297         return 0;       
298 }
299
300 /**
301  *  snd_card_free - frees given soundcard structure
302  *  @card: soundcard structure
303  *
304  *  This function releases the soundcard structure and the all assigned
305  *  devices automatically.  That is, you don't have to release the devices
306  *  by yourself.
307  *
308  *  Returns zero. Frees all associated devices and frees the control
309  *  interface associated to given soundcard.
310  */
311 int snd_card_free(struct snd_card *card)
312 {
313         struct snd_shutdown_f_ops *s_f_ops;
314
315         if (card == NULL)
316                 return -EINVAL;
317         write_lock(&snd_card_rwlock);
318         snd_cards[card->number] = NULL;
319         write_unlock(&snd_card_rwlock);
320
321 #ifdef CONFIG_PM
322         wake_up(&card->power_sleep);
323 #endif
324         /* wait, until all devices are ready for the free operation */
325         wait_event(card->shutdown_sleep, card->files == NULL);
326
327 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
328         if (snd_mixer_oss_notify_callback)
329                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
330 #endif
331         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
332                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
333                 /* Fatal, but this situation should never occur */
334         }
335         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
336                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
337                 /* Fatal, but this situation should never occur */
338         }
339         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
340                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
341                 /* Fatal, but this situation should never occur */
342         }
343         if (card->private_free)
344                 card->private_free(card);
345         snd_info_unregister(card->proc_id);
346         if (snd_info_card_free(card) < 0) {
347                 snd_printk(KERN_WARNING "unable to free card info\n");
348                 /* Not fatal error */
349         }
350         while (card->s_f_ops) {
351                 s_f_ops = card->s_f_ops;
352                 card->s_f_ops = s_f_ops->next;
353                 kfree(s_f_ops);
354         }
355         write_lock(&snd_card_rwlock);
356         snd_cards_lock &= ~(1 << card->number);
357         write_unlock(&snd_card_rwlock);
358         kfree(card);
359         return 0;
360 }
361
362 static void snd_card_free_thread(void * __card)
363 {
364         struct snd_card *card = __card;
365         struct module * module = card->module;
366
367         if (!try_module_get(module)) {
368                 snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
369                 module = NULL;
370         }
371
372         snd_card_free(card);
373
374         module_put(module);
375 }
376
377 /**
378  *  snd_card_free_in_thread - call snd_card_free() in thread
379  *  @card: soundcard structure
380  *
381  *  This function schedules the call of snd_card_free() function in a
382  *  work queue.  When all devices are released (non-busy), the work
383  *  is woken up and calls snd_card_free().
384  *
385  *  When a card can be disconnected at any time by hotplug service,
386  *  this function should be used in disconnect (or detach) callback
387  *  instead of calling snd_card_free() directly.
388  *  
389  *  Returns - zero otherwise a negative error code if the start of thread failed.
390  */
391 int snd_card_free_in_thread(struct snd_card *card)
392 {
393         if (card->files == NULL) {
394                 snd_card_free(card);
395                 return 0;
396         }
397
398         if (schedule_work(&card->free_workq))
399                 return 0;
400
401         snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
402         /* try to free the structure immediately */
403         snd_card_free(card);
404         return -EFAULT;
405 }
406
407 static void choose_default_id(struct snd_card *card)
408 {
409         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
410         char *id, *spos;
411         
412         id = spos = card->shortname;    
413         while (*id != '\0') {
414                 if (*id == ' ')
415                         spos = id + 1;
416                 id++;
417         }
418         id = card->id;
419         while (*spos != '\0' && !isalnum(*spos))
420                 spos++;
421         if (isdigit(*spos))
422                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
423         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
424                 if (isalnum(*spos))
425                         *id++ = *spos;
426                 spos++;
427         }
428         *id = '\0';
429
430         id = card->id;
431         
432         if (*id == '\0')
433                 strcpy(id, "default");
434
435         while (1) {
436                 if (loops-- == 0) {
437                         snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
438                         strcpy(card->id, card->proc_root->name);
439                         return;
440                 }
441                 if (!snd_info_check_reserved_words(id))
442                         goto __change;
443                 for (i = 0; i < snd_ecards_limit; i++) {
444                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
445                                 goto __change;
446                 }
447                 break;
448
449               __change:
450                 len = strlen(id);
451                 if (idx_flag) {
452                         if (id[len-1] != '9')
453                                 id[len-1]++;
454                         else
455                                 id[len-1] = 'A';
456                 } else if ((size_t)len <= sizeof(card->id) - 3) {
457                         strcat(id, "_1");
458                         idx_flag++;
459                 } else {
460                         spos = id + len - 2;
461                         if ((size_t)len <= sizeof(card->id) - 2)
462                                 spos++;
463                         *spos++ = '_';
464                         *spos++ = '1';
465                         *spos++ = '\0';
466                         idx_flag++;
467                 }
468         }
469 }
470
471 /**
472  *  snd_card_register - register the soundcard
473  *  @card: soundcard structure
474  *
475  *  This function registers all the devices assigned to the soundcard.
476  *  Until calling this, the ALSA control interface is blocked from the
477  *  external accesses.  Thus, you should call this function at the end
478  *  of the initialization of the card.
479  *
480  *  Returns zero otherwise a negative error code if the registrain failed.
481  */
482 int snd_card_register(struct snd_card *card)
483 {
484         int err;
485
486         snd_assert(card != NULL, return -EINVAL);
487         if ((err = snd_device_register_all(card)) < 0)
488                 return err;
489         write_lock(&snd_card_rwlock);
490         if (snd_cards[card->number]) {
491                 /* already registered */
492                 write_unlock(&snd_card_rwlock);
493                 return 0;
494         }
495         if (card->id[0] == '\0')
496                 choose_default_id(card);
497         snd_cards[card->number] = card;
498         write_unlock(&snd_card_rwlock);
499         init_info_for_card(card);
500 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
501         if (snd_mixer_oss_notify_callback)
502                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
503 #endif
504         return 0;
505 }
506
507 #ifdef CONFIG_PROC_FS
508 static struct snd_info_entry *snd_card_info_entry = NULL;
509
510 static void snd_card_info_read(struct snd_info_entry *entry,
511                                struct snd_info_buffer *buffer)
512 {
513         int idx, count;
514         struct snd_card *card;
515
516         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
517                 read_lock(&snd_card_rwlock);
518                 if ((card = snd_cards[idx]) != NULL) {
519                         count++;
520                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
521                                         idx,
522                                         card->id,
523                                         card->driver,
524                                         card->shortname);
525                         snd_iprintf(buffer, "                      %s\n",
526                                         card->longname);
527                 }
528                 read_unlock(&snd_card_rwlock);
529         }
530         if (!count)
531                 snd_iprintf(buffer, "--- no soundcards ---\n");
532 }
533
534 #ifdef CONFIG_SND_OSSEMUL
535
536 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
537 {
538         int idx, count;
539         struct snd_card *card;
540
541         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
542                 read_lock(&snd_card_rwlock);
543                 if ((card = snd_cards[idx]) != NULL) {
544                         count++;
545                         snd_iprintf(buffer, "%s\n", card->longname);
546                 }
547                 read_unlock(&snd_card_rwlock);
548         }
549         if (!count) {
550                 snd_iprintf(buffer, "--- no soundcards ---\n");
551         }
552 }
553
554 #endif
555
556 #ifdef MODULE
557 static struct snd_info_entry *snd_card_module_info_entry;
558 static void snd_card_module_info_read(struct snd_info_entry *entry,
559                                       struct snd_info_buffer *buffer)
560 {
561         int idx;
562         struct snd_card *card;
563
564         for (idx = 0; idx < SNDRV_CARDS; idx++) {
565                 read_lock(&snd_card_rwlock);
566                 if ((card = snd_cards[idx]) != NULL)
567                         snd_iprintf(buffer, "%2i %s\n",
568                                     idx, card->module->name);
569                 read_unlock(&snd_card_rwlock);
570         }
571 }
572 #endif
573
574 int __init snd_card_info_init(void)
575 {
576         struct snd_info_entry *entry;
577
578         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
579         if (! entry)
580                 return -ENOMEM;
581         entry->c.text.read_size = PAGE_SIZE;
582         entry->c.text.read = snd_card_info_read;
583         if (snd_info_register(entry) < 0) {
584                 snd_info_free_entry(entry);
585                 return -ENOMEM;
586         }
587         snd_card_info_entry = entry;
588
589 #ifdef MODULE
590         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
591         if (entry) {
592                 entry->c.text.read_size = PAGE_SIZE;
593                 entry->c.text.read = snd_card_module_info_read;
594                 if (snd_info_register(entry) < 0)
595                         snd_info_free_entry(entry);
596                 else
597                         snd_card_module_info_entry = entry;
598         }
599 #endif
600
601         return 0;
602 }
603
604 int __exit snd_card_info_done(void)
605 {
606         snd_info_unregister(snd_card_info_entry);
607 #ifdef MODULE
608         snd_info_unregister(snd_card_module_info_entry);
609 #endif
610         return 0;
611 }
612
613 #endif /* CONFIG_PROC_FS */
614
615 /**
616  *  snd_component_add - add a component string
617  *  @card: soundcard structure
618  *  @component: the component id string
619  *
620  *  This function adds the component id string to the supported list.
621  *  The component can be referred from the alsa-lib.
622  *
623  *  Returns zero otherwise a negative error code.
624  */
625   
626 int snd_component_add(struct snd_card *card, const char *component)
627 {
628         char *ptr;
629         int len = strlen(component);
630
631         ptr = strstr(card->components, component);
632         if (ptr != NULL) {
633                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
634                         return 1;
635         }
636         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
637                 snd_BUG();
638                 return -ENOMEM;
639         }
640         if (card->components[0] != '\0')
641                 strcat(card->components, " ");
642         strcat(card->components, component);
643         return 0;
644 }
645
646 /**
647  *  snd_card_file_add - add the file to the file list of the card
648  *  @card: soundcard structure
649  *  @file: file pointer
650  *
651  *  This function adds the file to the file linked-list of the card.
652  *  This linked-list is used to keep tracking the connection state,
653  *  and to avoid the release of busy resources by hotplug.
654  *
655  *  Returns zero or a negative error code.
656  */
657 int snd_card_file_add(struct snd_card *card, struct file *file)
658 {
659         struct snd_monitor_file *mfile;
660
661         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
662         if (mfile == NULL)
663                 return -ENOMEM;
664         mfile->file = file;
665         mfile->next = NULL;
666         spin_lock(&card->files_lock);
667         if (card->shutdown) {
668                 spin_unlock(&card->files_lock);
669                 kfree(mfile);
670                 return -ENODEV;
671         }
672         mfile->next = card->files;
673         card->files = mfile;
674         spin_unlock(&card->files_lock);
675         return 0;
676 }
677
678 /**
679  *  snd_card_file_remove - remove the file from the file list
680  *  @card: soundcard structure
681  *  @file: file pointer
682  *
683  *  This function removes the file formerly added to the card via
684  *  snd_card_file_add() function.
685  *  If all files are removed and the release of the card is
686  *  scheduled, it will wake up the the thread to call snd_card_free()
687  *  (see snd_card_free_in_thread() function).
688  *
689  *  Returns zero or a negative error code.
690  */
691 int snd_card_file_remove(struct snd_card *card, struct file *file)
692 {
693         struct snd_monitor_file *mfile, *pfile = NULL;
694
695         spin_lock(&card->files_lock);
696         mfile = card->files;
697         while (mfile) {
698                 if (mfile->file == file) {
699                         if (pfile)
700                                 pfile->next = mfile->next;
701                         else
702                                 card->files = mfile->next;
703                         break;
704                 }
705                 pfile = mfile;
706                 mfile = mfile->next;
707         }
708         spin_unlock(&card->files_lock);
709         if (card->files == NULL)
710                 wake_up(&card->shutdown_sleep);
711         if (!mfile) {
712                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
713                 return -ENOENT;
714         }
715         kfree(mfile);
716         return 0;
717 }
718
719 #ifdef CONFIG_PM
720 /**
721  *  snd_power_wait - wait until the power-state is changed.
722  *  @card: soundcard structure
723  *  @power_state: expected power state
724  *  @file: file structure for the O_NONBLOCK check (optional)
725  *
726  *  Waits until the power-state is changed.
727  *
728  *  Note: the power lock must be active before call.
729  */
730 int snd_power_wait(struct snd_card *card, unsigned int power_state, struct file *file)
731 {
732         wait_queue_t wait;
733         int result = 0;
734
735         /* fastpath */
736         if (snd_power_get_state(card) == power_state)
737                 return 0;
738         init_waitqueue_entry(&wait, current);
739         add_wait_queue(&card->power_sleep, &wait);
740         while (1) {
741                 if (card->shutdown) {
742                         result = -ENODEV;
743                         break;
744                 }
745                 if (snd_power_get_state(card) == power_state)
746                         break;
747 #if 0 /* block all devices */
748                 if (file && (file->f_flags & O_NONBLOCK)) {
749                         result = -EAGAIN;
750                         break;
751                 }
752 #endif
753                 set_current_state(TASK_UNINTERRUPTIBLE);
754                 snd_power_unlock(card);
755                 schedule_timeout(30 * HZ);
756                 snd_power_lock(card);
757         }
758         remove_wait_queue(&card->power_sleep, &wait);
759         return result;
760 }
761
762 #endif /* CONFIG_PM */