/* * Initialization routines * Copyright (c) by Jaroslav Kysela <perex@perex.cz> * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include <linux/init.h> #include <linux/sched.h> #include <linux/module.h> #include <linux/file.h> #include <linux/slab.h> #include <linux/time.h> #include <linux/ctype.h> #include <linux/pm.h> #include <sound/core.h> #include <sound/control.h> #include <sound/info.h> /* monitor files for graceful shutdown (hotplug) */ struct snd_monitor_file { struct file *file; const struct file_operations *disconnected_f_op; struct list_head shutdown_list; /* still need to shutdown */ struct list_head list; /* link of monitor files */ }; static DEFINE_SPINLOCK(shutdown_lock); static LIST_HEAD(shutdown_files); static const struct file_operations snd_shutdown_f_ops; static unsigned int snd_cards_lock; /* locked for registering/using */ struct snd_card *snd_cards[SNDRV_CARDS]; EXPORT_SYMBOL(snd_cards); static DEFINE_MUTEX(snd_card_mutex); static char *slots[SNDRV_CARDS]; module_param_array(slots, charp, NULL, 0444); MODULE_PARM_DESC(slots, "Module names assigned to the slots."); /* return non-zero if the given index is reserved for the given * module via slots option */ static int module_slot_match(struct module *module, int idx) { int match = 1; #ifdef MODULE const char *s1, *s2; if (!module || !module->name || !slots[idx]) return 0; s1 = module->name; s2 = slots[idx]; if (*s2 == '!') { match = 0; /* negative match */ s2++; } /* compare module name strings * hyphens are handled as equivalent with underscore */ for (;;) { char c1 = *s1++; char c2 = *s2++; if (c1 == '-') c1 = '_'; if (c2 == '-') c2 = '_'; if (c1 != c2) return !match; if (!c1) break; } #endif /* MODULE */ return match; } #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag); EXPORT_SYMBOL(snd_mixer_oss_notify_callback); #endif #ifdef CONFIG_PROC_FS static void snd_card_id_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { snd_iprintf(buffer, "%s\n", entry->card->id); } static inline int init_info_for_card(struct snd_card *card) { int err; struct snd_info_entry *entry; if ((err = snd_info_card_register(card)) < 0) { snd_printd("unable to create card info\n"); return err; } if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) { snd_printd("unable to create card entry\n"); return err; } entry->c.text.read = snd_card_id_read; if (snd_info_register(entry) < 0) { snd_info_free_entry(entry); entry = NULL; } card->proc_id = entry; return 0; } #else /* !CONFIG_PROC_FS */ #define init_info_for_card(card) #endif /** * snd_card_create - create and initialize a soundcard structure * @idx: card index (address) [0 ... (SNDRV_CARDS-1)] * @xid: card identification (ASCII string) * @module: top level module for locking * @extra_size: allocate this extra size after the main soundcard structure * @card_ret: the pointer to store the created card instance * * Creates and initializes a soundcard structure. * * The function allocates snd_card instance via kzalloc with the given * space for the driver to use freely. The allocated struct is stored * in the given card_ret pointer. * * Returns zero if successful or a negative error code. */ int snd_card_create(int idx, const char *xid, struct module *module, int extra_size, struct snd_card **card_ret) { struct snd_card *card; int err, idx2; if (snd_BUG_ON(!card_ret)) return -EINVAL; *card_ret = NULL; if (extra_size < 0) extra_size = 0; card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL); if (!card) return -ENOMEM; if (xid) strlcpy(card->id, xid, sizeof(card->id)); err = 0; mutex_lock(&snd_card_mutex); if (idx < 0) { for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) /* idx == -1 == 0xffff means: take any free slot */ if (~snd_cards_lock & idx & 1<<idx2) { if (module_slot_match(module, idx2)) { idx = idx2; break; } } } if (idx < 0) { for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) /* idx == -1 == 0xffff means: take any free slot */ if (~snd_cards_lock & idx & 1<<idx2) { if (!slots[idx2] || !*slots[idx2]) { idx = idx2; break; } } } if (idx < 0) err = -ENODEV; else if (idx < snd_ecards_limit) { if (snd_cards_lock & (1 << idx)) err = -EBUSY; /* invalid */ } else if (idx >= SNDRV_CARDS) err = -ENODEV; if (err < 0) { mutex_unlock(&snd_card_mutex); snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n", idx, snd_ecards_limit - 1, err); goto __error; } snd_cards_lock |= 1 << idx; /* lock it */ if (idx >= snd_ecards_limit) snd_ecards_limit = idx + 1; /* increase the limit */ mutex_unlock(&snd_card_mutex); card->number = idx; card->module = module; INIT_LIST_HEAD(&card->devices); init_rwsem(&card->controls_rwsem); rwlock_init(&card->ctl_files_rwlock); INIT_LIST_HEAD(&card->controls); INIT_LIST_HEAD(&card->ctl_files); spin_lock_init(&card->files_lock); INIT_LIST_HEAD(&card->files_list); init_waitqueue_head(&card->shutdown_sleep); #ifdef CONFIG_PM mutex_init(&card->power_lock); init_waitqueue_head(&card->power_sleep); #endif /* the control interface cannot be accessed from the user space until */ /* snd_cards_bitmask and snd_cards are set with snd_card_register */ err = snd_ctl_create(card); if (err < 0) { snd_printk(KERN_ERR "unable to register control minors\n"); goto __error; } err = snd_info_card_create(card); if (err < 0) { snd_printk(KERN_ERR "unable to create card info\n"); goto __error_ctl; } if (extra_size > 0) card->private_data = (char *)card + sizeof(struct snd_card); *card_ret = card; return 0; __error_ctl: snd_device_free_all(card, SNDRV_DEV_CMD_PRE); __error: kfree(card); return err; } EXPORT_SYMBOL(snd_card_create); /* return non-zero if a card is already locked */ int snd_card_locked(int card) { int locked; mutex_lock(&snd_card_mutex); locked = snd_cards_lock & (1 << card); mutex_unlock(&snd_card_mutex); return locked; } static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig) { return -ENODEV; } static ssize_t snd_disconnect_read(struct file *file, char __user *buf, size_t count, loff_t *offset) { return -ENODEV; } static ssize_t snd_disconnect_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) { return -ENODEV; } static int snd_disconnect_release(struct inode *inode, struct file *file) { struct snd_monitor_file *df = NULL, *_df; spin_lock(&shutdown_lock); list_for_each_entry(_df, &shutdown_files, shutdown_list) { if (_df->file == file) { df = _df; list_del_init(&df->shutdown_list); break; } } spin_unlock(&shutdown_lock); if (likely(df)) { if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync) df->disconnected_f_op->fasync(-1, file, 0); return df->disconnected_f_op->release(inode, file); } panic("%s(%p, %p) failed!", __func__, inode, file); } static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait) { return POLLERR | POLLNVAL; } static long snd_disconnect_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { return -ENODEV; } static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma) { return -ENODEV; } static int snd_disconnect_fasync(int fd, struct file *file, int on) { return -ENODEV; } static const struct file_operations snd_shutdown_f_ops = { .owner = THIS_MODULE, .llseek = snd_disconnect_llseek, .read = snd_disconnect_read, .write = snd_disconnect_write, .release = snd_disconnect_release, .poll = snd_disconnect_poll, .unlocked_ioctl = snd_disconnect_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = snd_disconnect_ioctl, #endif .mmap = snd_disconnect_mmap, .fasync = snd_disconnect_fasync }; /** * snd_card_disconnect - disconnect all APIs from the file-operations (user space) * @card: soundcard structure * * Disconnects all APIs from the file-operations (user space). * * Returns zero, otherwise a negative error code. * * Note: The current implementation replaces all active file->f_op with special * dummy file operations (they do nothing except release). */ int snd_card_disconnect(struct snd_card *card) { struct snd_monitor_file *mfile; int err; if (!card) return -EINVAL; spin_lock(&card->files_lock); if (card->shutdown) { spin_unlock(&card->files_lock); return 0; } card->shutdown = 1; spin_unlock(&card->files_lock); /* phase 1: disable fops (user space) operations for ALSA API */ mutex_lock(&snd_card_mutex); snd_cards[card->number] = NULL; snd_cards_lock &= ~(1 << card->number); mutex_unlock(&snd_card_mutex); /* phase 2: replace file->f_op with special dummy operations */ spin_lock(&card->files_lock); list_for_each_entry(mfile, &card->files_list, list) { /* it's critical part, use endless loop */ /* we have no room to fail */ mfile->disconnected_f_op = mfile->file->f_op; spin_lock(&shutdown_lock); list_add(&mfile->shutdown_list, &shutdown_files); spin_unlock(&shutdown_lock); mfile->file->f_op = &snd_shutdown_f_ops; fops_get(mfile->file->f_op); } spin_unlock(&card->files_lock); /* phase 3: notify all connected devices about disconnection */ /* at this point, they cannot respond to any calls except release() */ #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) if (snd_mixer_oss_notify_callback) snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT); #endif /* notify all devices that we are disconnected */ err = snd_device_disconnect_all(card); if (err < 0) snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number); snd_info_card_disconnect(card); if (card->card_dev) { device_unregister(card->card_dev); card->card_dev = NULL; } #ifdef CONFIG_PM wake_up(&card->power_sleep); #endif return 0; } EXPORT_SYMBOL(snd_card_disconnect); /** * snd_card_free - frees given soundcard structure * @card: soundcard structure * * This function releases the soundcard structure and the all assigned * devices automatically. That is, you don't have to release the devices * by yourself. * * Returns zero. Frees all associated devices and frees the control * interface associated to given soundcard. */ static int snd_card_do_free(struct snd_card *card) { #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) if (snd_mixer_oss_notify_callback) snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE); #endif if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) { snd_printk(KERN_ERR "unable to free all devices (pre)\n"); /* Fatal, but this situation should never occur */ } if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) { snd_printk(KERN_ERR "unable to free all devices (normal)\n"); /* Fatal, but this situation should never occur */ } if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) { snd_printk(KERN_ERR "unable to free all devices (post)\n"); /* Fatal, but this situation should never occur */ } if (card->private_free) card->private_free(card); snd_info_free_entry(card->proc_id); if (snd_info_card_free(card) < 0) { snd_printk(KERN_WARNING "unable to free card info\n"); /* Not fatal error */ } kfree(card); return 0; } int snd_card_free_when_closed(struct snd_card *card) { int free_now = 0; int ret = snd_card_disconnect(card); if (ret) return ret; spin_lock(&card->files_lock); if (list_empty(&card->files_list)) free_now = 1; else card->free_on_last_close = 1; spin_unlock(&card->files_lock); if (free_now) snd_card_do_free(card); return 0; } EXPORT_SYMBOL(snd_card_free_when_closed); int snd_card_free(struct snd_card *card) { int ret = snd_card_disconnect(card); if (ret) return ret; /* wait, until all devices are ready for the free operation */ wait_event(card->shutdown_sleep, list_empty(&card->files_list)); snd_card_do_free(card); return 0; } EXPORT_SYMBOL(snd_card_free); static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid) { int i, len, idx_flag = 0, loops = SNDRV_CARDS; const char *spos, *src; char *id; if (nid == NULL) { id = card->shortname; spos = src = id; while (*id != '\0') { if (*id == ' ') spos = id + 1; id++; } } else { spos = src = nid; } id = card->id; while (*spos != '\0' && !isalnum(*spos)) spos++; if (isdigit(*spos)) *id++ = isalpha(src[0]) ? src[0] : 'D'; while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) { if (isalnum(*spos)) *id++ = *spos; spos++; } *id = '\0'; id = card->id; if (*id == '\0') strcpy(id, "Default"); while (1) { if (loops-- == 0) { snd_printk(KERN_ERR "unable to set card id (%s)\n", id); strcpy(card->id, card->proc_root->name); return; } if (!snd_info_check_reserved_words(id)) goto __change; for (i = 0; i < snd_ecards_limit; i++) { if (snd_cards[i] && !strcmp(snd_cards[i]->id, id)) goto __change; } break; __change: len = strlen(id); if (idx_flag) { if (id[len-1] != '9') id[len-1]++; else id[len-1] = 'A'; } else if ((size_t)len <= sizeof(card->id) - 3) { strcat(id, "_1"); idx_flag++; } else { spos = id + len - 2; if ((size_t)len <= sizeof(card->id) - 2) spos++; *(char *)spos++ = '_'; *(char *)spos++ = '1'; *(char *)spos++ = '\0'; idx_flag++; } } } /** * snd_card_set_id - set card identification name * @card: soundcard structure * @nid: new identification string * * This function sets the card identification and checks for name * collisions. */ void snd_card_set_id(struct snd_card *card, const char *nid) { /* check if user specified own card->id */ if (card->id[0] != '\0') return; mutex_lock(&snd_card_mutex); snd_card_set_id_no_lock(card, nid); mutex_unlock(&snd_card_mutex); } EXPORT_SYMBOL(snd_card_set_id); static ssize_t card_id_show_attr(struct device *dev, struct device_attribute *attr, char *buf) { struct snd_card *card = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)"); } static ssize_t card_id_store_attr(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct snd_card *card = dev_get_drvdata(dev); char buf1[sizeof(card->id)]; size_t copy = count > sizeof(card->id) - 1 ? sizeof(card->id) - 1 : count; size_t idx; int c; for (idx = 0; idx < copy; idx++) { c = buf[idx]; if (!isalnum(c) && c != '_' && c != '-') return -EINVAL; } memcpy(buf1, buf, copy); buf1[copy] = '\0'; mutex_lock(&snd_card_mutex); if (!snd_info_check_reserved_words(buf1)) { __exist: mutex_unlock(&snd_card_mutex); return -EEXIST; } for (idx = 0; idx < snd_ecards_limit; idx++) { if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) { if (card == snd_cards[idx]) goto __ok; else goto __exist; } } strcpy(card->id, buf1); snd_info_card_id_change(card); __ok: mutex_unlock(&snd_card_mutex); return count; } static struct device_attribute card_id_attrs = __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr); static ssize_t card_number_show_attr(struct device *dev, struct device_attribute *attr, char *buf) { struct snd_card *card = dev_get_drvdata(dev); return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1); } static struct device_attribute card_number_attrs = __ATTR(number, S_IRUGO, card_number_show_attr, NULL); /** * snd_card_register - register the soundcard * @card: soundcard structure * * This function registers all the devices assigned to the soundcard. * Until calling this, the ALSA control interface is blocked from the * external accesses. Thus, you should call this function at the end * of the initialization of the card. * * Returns zero otherwise a negative error code if the registration failed. */ int snd_card_register(struct snd_card *card) { int err; if (snd_BUG_ON(!card)) return -EINVAL; if (!card->card_dev) { card->card_dev = device_create(sound_class, card->dev, MKDEV(0, 0), card, "card%i", card->number); if (IS_ERR(card->card_dev)) card->card_dev = NULL; } if ((err = snd_device_register_all(card)) < 0) return err; mutex_lock(&snd_card_mutex); if (snd_cards[card->number]) { /* already registered */ mutex_unlock(&snd_card_mutex); return 0; } snd_card_set_id_no_lock(card, card->id[0] == '\0' ? NULL : card->id); snd_cards[card->number] = card; mutex_unlock(&snd_card_mutex); init_info_for_card(card); #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) if (snd_mixer_oss_notify_callback) snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER); #endif if (card->card_dev) { err = device_create_file(card->card_dev, &card_id_attrs); if (err < 0) return err; err = device_create_file(card->card_dev, &card_number_attrs); if (err < 0) return err; } return 0; } EXPORT_SYMBOL(snd_card_register); #ifdef CONFIG_PROC_FS static struct snd_info_entry *snd_card_info_entry; static void snd_card_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { int idx, count; struct snd_card *card; for (idx = count = 0; idx < SNDRV_CARDS; idx++) { mutex_lock(&snd_card_mutex); if ((card = snd_cards[idx]) != NULL) { count++; snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n", idx, card->id, card->driver, card->shortname); snd_iprintf(buffer, " %s\n", card->longname); } mutex_unlock(&snd_card_mutex); } if (!count) snd_iprintf(buffer, "--- no soundcards ---\n"); } #ifdef CONFIG_SND_OSSEMUL void snd_card_info_read_oss(struct snd_info_buffer *buffer) { int idx, count; struct snd_card *card; for (idx = count = 0; idx < SNDRV_CARDS; idx++) { mutex_lock(&snd_card_mutex); if ((card = snd_cards[idx]) != NULL) { count++; snd_iprintf(buffer, "%s\n", card->longname); } mutex_unlock(&snd_card_mutex); } if (!count) { snd_iprintf(buffer, "--- no soundcards ---\n"); } } #endif #ifdef MODULE static struct snd_info_entry *snd_card_module_info_entry; static void snd_card_module_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { int idx; struct snd_card *card; for (idx = 0; idx < SNDRV_CARDS; idx++) { mutex_lock(&snd_card_mutex); if ((card = snd_cards[idx]) != NULL) snd_iprintf(buffer, "%2i %s\n", idx, card->module->name); mutex_unlock(&snd_card_mutex); } } #endif int __init snd_card_info_init(void) { struct snd_info_entry *entry; entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL); if (! entry) return -ENOMEM; entry->c.text.read = snd_card_info_read; if (snd_info_register(entry) < 0) { snd_info_free_entry(entry); return -ENOMEM; } snd_card_info_entry = entry; #ifdef MODULE entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL); if (entry) { entry->c.text.read = snd_card_module_info_read; if (snd_info_register(entry) < 0) snd_info_free_entry(entry); else snd_card_module_info_entry = entry; } #endif return 0; } int __exit snd_card_info_done(void) { snd_info_free_entry(snd_card_info_entry); #ifdef MODULE snd_info_free_entry(snd_card_module_info_entry); #endif return 0; } #endif /* CONFIG_PROC_FS */ /** * snd_component_add - add a component string * @card: soundcard structure * @component: the component id string * * This function adds the component id string to the supported list. * The component can be referred from the alsa-lib. * * Returns zero otherwise a negative error code. */ int snd_component_add(struct snd_card *card, const char *component) { char *ptr; int len = strlen(component); ptr = strstr(card->components, component); if (ptr != NULL) { if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */ return 1; } if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) { snd_BUG(); return -ENOMEM; } if (card->components[0] != '\0') strcat(card->components, " "); strcat(card->components, component); return 0; } EXPORT_SYMBOL(snd_component_add); /** * snd_card_file_add - add the file to the file list of the card * @card: soundcard structure * @file: file pointer * * This function adds the file to the file linked-list of the card. * This linked-list is used to keep tracking the connection state, * and to avoid the release of busy resources by hotplug. * * Returns zero or a negative error code. */ int snd_card_file_add(struct snd_card *card, struct file *file) { struct snd_monitor_file *mfile; mfile = kmalloc(sizeof(*mfile), GFP_KERNEL); if (mfile == NULL) return -ENOMEM; mfile->file = file; mfile->disconnected_f_op = NULL; INIT_LIST_HEAD(&mfile->shutdown_list); spin_lock(&card->files_lock); if (card->shutdown) { spin_unlock(&card->files_lock); kfree(mfile); return -ENODEV; } list_add(&mfile->list, &card->files_list); spin_unlock(&card->files_lock); return 0; } EXPORT_SYMBOL(snd_card_file_add); /** * snd_card_file_remove - remove the file from the file list * @card: soundcard structure * @file: file pointer * * This function removes the file formerly added to the card via * snd_card_file_add() function. * If all files are removed and snd_card_free_when_closed() was * called beforehand, it processes the pending release of * resources. * * Returns zero or a negative error code. */ int snd_card_file_remove(struct snd_card *card, struct file *file) { struct snd_monitor_file *mfile, *found = NULL; int last_close = 0; spin_lock(&card->files_lock); list_for_each_entry(mfile, &card->files_list, list) { if (mfile->file == file) { list_del(&mfile->list); spin_lock(&shutdown_lock); list_del(&mfile->shutdown_list); spin_unlock(&shutdown_lock); if (mfile->disconnected_f_op) fops_put(mfile->disconnected_f_op); found = mfile; break; } } if (list_empty(&card->files_list)) last_close = 1; spin_unlock(&card->files_lock); if (last_close) { wake_up(&card->shutdown_sleep); if (card->free_on_last_close) snd_card_do_free(card); } if (!found) { snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file); return -ENOENT; } kfree(found); return 0; } EXPORT_SYMBOL(snd_card_file_remove); #ifdef CONFIG_PM /** * snd_power_wait - wait until the power-state is changed. * @card: soundcard structure * @power_state: expected power state * * Waits until the power-state is changed. * * Note: the power lock must be active before call. */ int snd_power_wait(struct snd_card *card, unsigned int power_state) { wait_queue_t wait; int result = 0; /* fastpath */ if (snd_power_get_state(card) == power_state) return 0; init_waitqueue_entry(&wait, current); add_wait_queue(&card->power_sleep, &wait); while (1) { if (card->shutdown) { result = -ENODEV; break; } if (snd_power_get_state(card) == power_state) break; set_current_state(TASK_UNINTERRUPTIBLE); snd_power_unlock(card); schedule_timeout(30 * HZ); snd_power_lock(card); } remove_wait_queue(&card->power_sleep, &wait); return result; } EXPORT_SYMBOL(snd_power_wait); #endif /* CONFIG_PM */