[PATCH] mark f_ops const in the inode
[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;
227         const struct file_operations *old_f_ops;
228         int err;
229
230         spin_lock(&card->files_lock);
231         if (card->shutdown) {
232                 spin_unlock(&card->files_lock);
233                 return 0;
234         }
235         card->shutdown = 1;
236         spin_unlock(&card->files_lock);
237
238         /* phase 1: disable fops (user space) operations for ALSA API */
239         write_lock(&snd_card_rwlock);
240         snd_cards[card->number] = NULL;
241         write_unlock(&snd_card_rwlock);
242         
243         /* phase 2: replace file->f_op with special dummy operations */
244         
245         spin_lock(&card->files_lock);
246         mfile = card->files;
247         while (mfile) {
248                 file = mfile->file;
249
250                 /* it's critical part, use endless loop */
251                 /* we have no room to fail */
252                 s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
253                 if (s_f_ops == NULL)
254                         panic("Atomic allocation failed for snd_shutdown_f_ops!");
255
256                 f_ops = &s_f_ops->f_ops;
257
258                 memset(f_ops, 0, sizeof(*f_ops));
259                 f_ops->owner = file->f_op->owner;
260                 f_ops->release = file->f_op->release;
261                 f_ops->llseek = snd_disconnect_llseek;
262                 f_ops->read = snd_disconnect_read;
263                 f_ops->write = snd_disconnect_write;
264                 f_ops->poll = snd_disconnect_poll;
265                 f_ops->unlocked_ioctl = snd_disconnect_ioctl;
266 #ifdef CONFIG_COMPAT
267                 f_ops->compat_ioctl = snd_disconnect_ioctl;
268 #endif
269                 f_ops->mmap = snd_disconnect_mmap;
270                 f_ops->fasync = snd_disconnect_fasync;
271
272                 s_f_ops->next = card->s_f_ops;
273                 card->s_f_ops = s_f_ops;
274                 
275                 f_ops = fops_get(f_ops);
276
277                 old_f_ops = file->f_op;
278                 file->f_op = f_ops;     /* must be atomic */
279                 fops_put(old_f_ops);
280                 
281                 mfile = mfile->next;
282         }
283         spin_unlock(&card->files_lock); 
284
285         /* phase 3: notify all connected devices about disconnection */
286         /* at this point, they cannot respond to any calls except release() */
287
288 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
289         if (snd_mixer_oss_notify_callback)
290                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
291 #endif
292
293         /* notify all devices that we are disconnected */
294         err = snd_device_disconnect_all(card);
295         if (err < 0)
296                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
297
298         return 0;       
299 }
300
301 /**
302  *  snd_card_free - frees given soundcard structure
303  *  @card: soundcard structure
304  *
305  *  This function releases the soundcard structure and the all assigned
306  *  devices automatically.  That is, you don't have to release the devices
307  *  by yourself.
308  *
309  *  Returns zero. Frees all associated devices and frees the control
310  *  interface associated to given soundcard.
311  */
312 int snd_card_free(struct snd_card *card)
313 {
314         struct snd_shutdown_f_ops *s_f_ops;
315
316         if (card == NULL)
317                 return -EINVAL;
318         write_lock(&snd_card_rwlock);
319         snd_cards[card->number] = NULL;
320         write_unlock(&snd_card_rwlock);
321
322 #ifdef CONFIG_PM
323         wake_up(&card->power_sleep);
324 #endif
325         /* wait, until all devices are ready for the free operation */
326         wait_event(card->shutdown_sleep, card->files == NULL);
327
328 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
329         if (snd_mixer_oss_notify_callback)
330                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
331 #endif
332         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
333                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
334                 /* Fatal, but this situation should never occur */
335         }
336         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
337                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
338                 /* Fatal, but this situation should never occur */
339         }
340         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
341                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
342                 /* Fatal, but this situation should never occur */
343         }
344         if (card->private_free)
345                 card->private_free(card);
346         snd_info_unregister(card->proc_id);
347         if (snd_info_card_free(card) < 0) {
348                 snd_printk(KERN_WARNING "unable to free card info\n");
349                 /* Not fatal error */
350         }
351         while (card->s_f_ops) {
352                 s_f_ops = card->s_f_ops;
353                 card->s_f_ops = s_f_ops->next;
354                 kfree(s_f_ops);
355         }
356         write_lock(&snd_card_rwlock);
357         snd_cards_lock &= ~(1 << card->number);
358         write_unlock(&snd_card_rwlock);
359         kfree(card);
360         return 0;
361 }
362
363 static void snd_card_free_thread(void * __card)
364 {
365         struct snd_card *card = __card;
366         struct module * module = card->module;
367
368         if (!try_module_get(module)) {
369                 snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
370                 module = NULL;
371         }
372
373         snd_card_free(card);
374
375         module_put(module);
376 }
377
378 /**
379  *  snd_card_free_in_thread - call snd_card_free() in thread
380  *  @card: soundcard structure
381  *
382  *  This function schedules the call of snd_card_free() function in a
383  *  work queue.  When all devices are released (non-busy), the work
384  *  is woken up and calls snd_card_free().
385  *
386  *  When a card can be disconnected at any time by hotplug service,
387  *  this function should be used in disconnect (or detach) callback
388  *  instead of calling snd_card_free() directly.
389  *  
390  *  Returns - zero otherwise a negative error code if the start of thread failed.
391  */
392 int snd_card_free_in_thread(struct snd_card *card)
393 {
394         if (card->files == NULL) {
395                 snd_card_free(card);
396                 return 0;
397         }
398
399         if (schedule_work(&card->free_workq))
400                 return 0;
401
402         snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
403         /* try to free the structure immediately */
404         snd_card_free(card);
405         return -EFAULT;
406 }
407
408 static void choose_default_id(struct snd_card *card)
409 {
410         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
411         char *id, *spos;
412         
413         id = spos = card->shortname;    
414         while (*id != '\0') {
415                 if (*id == ' ')
416                         spos = id + 1;
417                 id++;
418         }
419         id = card->id;
420         while (*spos != '\0' && !isalnum(*spos))
421                 spos++;
422         if (isdigit(*spos))
423                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
424         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
425                 if (isalnum(*spos))
426                         *id++ = *spos;
427                 spos++;
428         }
429         *id = '\0';
430
431         id = card->id;
432         
433         if (*id == '\0')
434                 strcpy(id, "default");
435
436         while (1) {
437                 if (loops-- == 0) {
438                         snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
439                         strcpy(card->id, card->proc_root->name);
440                         return;
441                 }
442                 if (!snd_info_check_reserved_words(id))
443                         goto __change;
444                 for (i = 0; i < snd_ecards_limit; i++) {
445                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
446                                 goto __change;
447                 }
448                 break;
449
450               __change:
451                 len = strlen(id);
452                 if (idx_flag) {
453                         if (id[len-1] != '9')
454                                 id[len-1]++;
455                         else
456                                 id[len-1] = 'A';
457                 } else if ((size_t)len <= sizeof(card->id) - 3) {
458                         strcat(id, "_1");
459                         idx_flag++;
460                 } else {
461                         spos = id + len - 2;
462                         if ((size_t)len <= sizeof(card->id) - 2)
463                                 spos++;
464                         *spos++ = '_';
465                         *spos++ = '1';
466                         *spos++ = '\0';
467                         idx_flag++;
468                 }
469         }
470 }
471
472 /**
473  *  snd_card_register - register the soundcard
474  *  @card: soundcard structure
475  *
476  *  This function registers all the devices assigned to the soundcard.
477  *  Until calling this, the ALSA control interface is blocked from the
478  *  external accesses.  Thus, you should call this function at the end
479  *  of the initialization of the card.
480  *
481  *  Returns zero otherwise a negative error code if the registrain failed.
482  */
483 int snd_card_register(struct snd_card *card)
484 {
485         int err;
486
487         snd_assert(card != NULL, return -EINVAL);
488         if ((err = snd_device_register_all(card)) < 0)
489                 return err;
490         write_lock(&snd_card_rwlock);
491         if (snd_cards[card->number]) {
492                 /* already registered */
493                 write_unlock(&snd_card_rwlock);
494                 return 0;
495         }
496         if (card->id[0] == '\0')
497                 choose_default_id(card);
498         snd_cards[card->number] = card;
499         write_unlock(&snd_card_rwlock);
500         init_info_for_card(card);
501 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
502         if (snd_mixer_oss_notify_callback)
503                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
504 #endif
505         return 0;
506 }
507
508 #ifdef CONFIG_PROC_FS
509 static struct snd_info_entry *snd_card_info_entry = NULL;
510
511 static void snd_card_info_read(struct snd_info_entry *entry,
512                                struct snd_info_buffer *buffer)
513 {
514         int idx, count;
515         struct snd_card *card;
516
517         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
518                 read_lock(&snd_card_rwlock);
519                 if ((card = snd_cards[idx]) != NULL) {
520                         count++;
521                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
522                                         idx,
523                                         card->id,
524                                         card->driver,
525                                         card->shortname);
526                         snd_iprintf(buffer, "                      %s\n",
527                                         card->longname);
528                 }
529                 read_unlock(&snd_card_rwlock);
530         }
531         if (!count)
532                 snd_iprintf(buffer, "--- no soundcards ---\n");
533 }
534
535 #ifdef CONFIG_SND_OSSEMUL
536
537 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
538 {
539         int idx, count;
540         struct snd_card *card;
541
542         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
543                 read_lock(&snd_card_rwlock);
544                 if ((card = snd_cards[idx]) != NULL) {
545                         count++;
546                         snd_iprintf(buffer, "%s\n", card->longname);
547                 }
548                 read_unlock(&snd_card_rwlock);
549         }
550         if (!count) {
551                 snd_iprintf(buffer, "--- no soundcards ---\n");
552         }
553 }
554
555 #endif
556
557 #ifdef MODULE
558 static struct snd_info_entry *snd_card_module_info_entry;
559 static void snd_card_module_info_read(struct snd_info_entry *entry,
560                                       struct snd_info_buffer *buffer)
561 {
562         int idx;
563         struct snd_card *card;
564
565         for (idx = 0; idx < SNDRV_CARDS; idx++) {
566                 read_lock(&snd_card_rwlock);
567                 if ((card = snd_cards[idx]) != NULL)
568                         snd_iprintf(buffer, "%2i %s\n",
569                                     idx, card->module->name);
570                 read_unlock(&snd_card_rwlock);
571         }
572 }
573 #endif
574
575 int __init snd_card_info_init(void)
576 {
577         struct snd_info_entry *entry;
578
579         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
580         if (! entry)
581                 return -ENOMEM;
582         entry->c.text.read_size = PAGE_SIZE;
583         entry->c.text.read = snd_card_info_read;
584         if (snd_info_register(entry) < 0) {
585                 snd_info_free_entry(entry);
586                 return -ENOMEM;
587         }
588         snd_card_info_entry = entry;
589
590 #ifdef MODULE
591         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
592         if (entry) {
593                 entry->c.text.read_size = PAGE_SIZE;
594                 entry->c.text.read = snd_card_module_info_read;
595                 if (snd_info_register(entry) < 0)
596                         snd_info_free_entry(entry);
597                 else
598                         snd_card_module_info_entry = entry;
599         }
600 #endif
601
602         return 0;
603 }
604
605 int __exit snd_card_info_done(void)
606 {
607         snd_info_unregister(snd_card_info_entry);
608 #ifdef MODULE
609         snd_info_unregister(snd_card_module_info_entry);
610 #endif
611         return 0;
612 }
613
614 #endif /* CONFIG_PROC_FS */
615
616 /**
617  *  snd_component_add - add a component string
618  *  @card: soundcard structure
619  *  @component: the component id string
620  *
621  *  This function adds the component id string to the supported list.
622  *  The component can be referred from the alsa-lib.
623  *
624  *  Returns zero otherwise a negative error code.
625  */
626   
627 int snd_component_add(struct snd_card *card, const char *component)
628 {
629         char *ptr;
630         int len = strlen(component);
631
632         ptr = strstr(card->components, component);
633         if (ptr != NULL) {
634                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
635                         return 1;
636         }
637         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
638                 snd_BUG();
639                 return -ENOMEM;
640         }
641         if (card->components[0] != '\0')
642                 strcat(card->components, " ");
643         strcat(card->components, component);
644         return 0;
645 }
646
647 /**
648  *  snd_card_file_add - add the file to the file list of the card
649  *  @card: soundcard structure
650  *  @file: file pointer
651  *
652  *  This function adds the file to the file linked-list of the card.
653  *  This linked-list is used to keep tracking the connection state,
654  *  and to avoid the release of busy resources by hotplug.
655  *
656  *  Returns zero or a negative error code.
657  */
658 int snd_card_file_add(struct snd_card *card, struct file *file)
659 {
660         struct snd_monitor_file *mfile;
661
662         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
663         if (mfile == NULL)
664                 return -ENOMEM;
665         mfile->file = file;
666         mfile->next = NULL;
667         spin_lock(&card->files_lock);
668         if (card->shutdown) {
669                 spin_unlock(&card->files_lock);
670                 kfree(mfile);
671                 return -ENODEV;
672         }
673         mfile->next = card->files;
674         card->files = mfile;
675         spin_unlock(&card->files_lock);
676         return 0;
677 }
678
679 /**
680  *  snd_card_file_remove - remove the file from the file list
681  *  @card: soundcard structure
682  *  @file: file pointer
683  *
684  *  This function removes the file formerly added to the card via
685  *  snd_card_file_add() function.
686  *  If all files are removed and the release of the card is
687  *  scheduled, it will wake up the the thread to call snd_card_free()
688  *  (see snd_card_free_in_thread() function).
689  *
690  *  Returns zero or a negative error code.
691  */
692 int snd_card_file_remove(struct snd_card *card, struct file *file)
693 {
694         struct snd_monitor_file *mfile, *pfile = NULL;
695
696         spin_lock(&card->files_lock);
697         mfile = card->files;
698         while (mfile) {
699                 if (mfile->file == file) {
700                         if (pfile)
701                                 pfile->next = mfile->next;
702                         else
703                                 card->files = mfile->next;
704                         break;
705                 }
706                 pfile = mfile;
707                 mfile = mfile->next;
708         }
709         spin_unlock(&card->files_lock);
710         if (card->files == NULL)
711                 wake_up(&card->shutdown_sleep);
712         if (!mfile) {
713                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
714                 return -ENOENT;
715         }
716         kfree(mfile);
717         return 0;
718 }
719
720 #ifdef CONFIG_PM
721 /**
722  *  snd_power_wait - wait until the power-state is changed.
723  *  @card: soundcard structure
724  *  @power_state: expected power state
725  *  @file: file structure for the O_NONBLOCK check (optional)
726  *
727  *  Waits until the power-state is changed.
728  *
729  *  Note: the power lock must be active before call.
730  */
731 int snd_power_wait(struct snd_card *card, unsigned int power_state, struct file *file)
732 {
733         wait_queue_t wait;
734         int result = 0;
735
736         /* fastpath */
737         if (snd_power_get_state(card) == power_state)
738                 return 0;
739         init_waitqueue_entry(&wait, current);
740         add_wait_queue(&card->power_sleep, &wait);
741         while (1) {
742                 if (card->shutdown) {
743                         result = -ENODEV;
744                         break;
745                 }
746                 if (snd_power_get_state(card) == power_state)
747                         break;
748 #if 0 /* block all devices */
749                 if (file && (file->f_flags & O_NONBLOCK)) {
750                         result = -EAGAIN;
751                         break;
752                 }
753 #endif
754                 set_current_state(TASK_UNINTERRUPTIBLE);
755                 snd_power_unlock(card);
756                 schedule_timeout(30 * HZ);
757                 snd_power_lock(card);
758         }
759         remove_wait_queue(&card->power_sleep, &wait);
760         return result;
761 }
762
763 #endif /* CONFIG_PM */