diff options
Diffstat (limited to 'sound/core/timer.c')
-rw-r--r-- | sound/core/timer.c | 155 |
1 files changed, 108 insertions, 47 deletions
diff --git a/sound/core/timer.c b/sound/core/timer.c index 152254193c69..f8a4b2a2f8f6 100644 --- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -87,6 +87,9 @@ static LIST_HEAD(snd_timer_slave_list); /* lock for slave active lists */ static DEFINE_SPINLOCK(slave_active_lock); +#define MAX_SLAVE_INSTANCES 1000 +static int num_slaves; + static DEFINE_MUTEX(register_mutex); static int snd_timer_free(struct snd_timer *timer); @@ -179,7 +182,7 @@ static void snd_timer_request(struct snd_timer_id *tid) * * call this with register_mutex down. */ -static void snd_timer_check_slave(struct snd_timer_instance *slave) +static int snd_timer_check_slave(struct snd_timer_instance *slave) { struct snd_timer *timer; struct snd_timer_instance *master; @@ -189,16 +192,21 @@ static void snd_timer_check_slave(struct snd_timer_instance *slave) list_for_each_entry(master, &timer->open_list_head, open_list) { if (slave->slave_class == master->slave_class && slave->slave_id == master->slave_id) { + if (master->timer->num_instances >= + master->timer->max_instances) + return -EBUSY; list_move_tail(&slave->open_list, &master->slave_list_head); + master->timer->num_instances++; spin_lock_irq(&slave_active_lock); slave->master = master; slave->timer = master->timer; spin_unlock_irq(&slave_active_lock); - return; + return 0; } } } + return 0; } /* @@ -207,7 +215,7 @@ static void snd_timer_check_slave(struct snd_timer_instance *slave) * * call this with register_mutex down. */ -static void snd_timer_check_master(struct snd_timer_instance *master) +static int snd_timer_check_master(struct snd_timer_instance *master) { struct snd_timer_instance *slave, *tmp; @@ -215,7 +223,11 @@ static void snd_timer_check_master(struct snd_timer_instance *master) list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) { if (slave->slave_class == master->slave_class && slave->slave_id == master->slave_id) { + if (master->timer->num_instances >= + master->timer->max_instances) + return -EBUSY; list_move_tail(&slave->open_list, &master->slave_list_head); + master->timer->num_instances++; spin_lock_irq(&slave_active_lock); spin_lock(&master->timer->lock); slave->master = master; @@ -227,8 +239,12 @@ static void snd_timer_check_master(struct snd_timer_instance *master) spin_unlock_irq(&slave_active_lock); } } + return 0; } +static int snd_timer_close_locked(struct snd_timer_instance *timeri, + struct device **card_devp_to_put); + /* * open a timer instance * when opening a master, the slave id must be here given. @@ -239,33 +255,42 @@ int snd_timer_open(struct snd_timer_instance **ti, { struct snd_timer *timer; struct snd_timer_instance *timeri = NULL; + struct device *card_dev_to_put = NULL; + int err; + mutex_lock(®ister_mutex); if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) { /* open a slave instance */ if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE || tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) { pr_debug("ALSA: timer: invalid slave class %i\n", tid->dev_sclass); - return -EINVAL; + err = -EINVAL; + goto unlock; + } + if (num_slaves >= MAX_SLAVE_INSTANCES) { + err = -EBUSY; + goto unlock; } - mutex_lock(®ister_mutex); timeri = snd_timer_instance_new(owner, NULL); if (!timeri) { - mutex_unlock(®ister_mutex); - return -ENOMEM; + err = -ENOMEM; + goto unlock; } timeri->slave_class = tid->dev_sclass; timeri->slave_id = tid->device; timeri->flags |= SNDRV_TIMER_IFLG_SLAVE; list_add_tail(&timeri->open_list, &snd_timer_slave_list); - snd_timer_check_slave(timeri); - mutex_unlock(®ister_mutex); - *ti = timeri; - return 0; + num_slaves++; + err = snd_timer_check_slave(timeri); + if (err < 0) { + snd_timer_close_locked(timeri, &card_dev_to_put); + timeri = NULL; + } + goto unlock; } /* open a master instance */ - mutex_lock(®ister_mutex); timer = snd_timer_find(tid); #ifdef CONFIG_MODULES if (!timer) { @@ -276,21 +301,26 @@ int snd_timer_open(struct snd_timer_instance **ti, } #endif if (!timer) { - mutex_unlock(®ister_mutex); - return -ENODEV; + err = -ENODEV; + goto unlock; } if (!list_empty(&timer->open_list_head)) { - timeri = list_entry(timer->open_list_head.next, + struct snd_timer_instance *t = + list_entry(timer->open_list_head.next, struct snd_timer_instance, open_list); - if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) { - mutex_unlock(®ister_mutex); - return -EBUSY; + if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) { + err = -EBUSY; + goto unlock; } } + if (timer->num_instances >= timer->max_instances) { + err = -EBUSY; + goto unlock; + } timeri = snd_timer_instance_new(owner, timer); if (!timeri) { - mutex_unlock(®ister_mutex); - return -ENOMEM; + err = -ENOMEM; + goto unlock; } /* take a card refcount for safe disconnection */ if (timer->card) @@ -299,45 +329,57 @@ int snd_timer_open(struct snd_timer_instance **ti, timeri->slave_id = slave_id; if (list_empty(&timer->open_list_head) && timer->hw.open) { - int err = timer->hw.open(timer); + err = timer->hw.open(timer); if (err) { kfree(timeri->owner); kfree(timeri); + timeri = NULL; if (timer->card) - put_device(&timer->card->card_dev); + card_dev_to_put = &timer->card->card_dev; module_put(timer->module); - mutex_unlock(®ister_mutex); - return err; + goto unlock; } } list_add_tail(&timeri->open_list, &timer->open_list_head); - snd_timer_check_master(timeri); + timer->num_instances++; + err = snd_timer_check_master(timeri); + if (err < 0) { + snd_timer_close_locked(timeri, &card_dev_to_put); + timeri = NULL; + } + + unlock: mutex_unlock(®ister_mutex); + /* put_device() is called after unlock for avoiding deadlock */ + if (card_dev_to_put) + put_device(card_dev_to_put); *ti = timeri; - return 0; + return err; } +EXPORT_SYMBOL(snd_timer_open); /* * close a timer instance + * call this with register_mutex down. */ -int snd_timer_close(struct snd_timer_instance *timeri) +static int snd_timer_close_locked(struct snd_timer_instance *timeri, + struct device **card_devp_to_put) { struct snd_timer *timer = NULL; struct snd_timer_instance *slave, *tmp; - if (snd_BUG_ON(!timeri)) - return -ENXIO; - - mutex_lock(®ister_mutex); list_del(&timeri->open_list); + if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) + num_slaves--; /* force to stop the timer */ snd_timer_stop(timeri); timer = timeri->timer; if (timer) { + timer->num_instances--; /* wait, until the active callback is finished */ spin_lock_irq(&timer->lock); while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) { @@ -353,6 +395,7 @@ int snd_timer_close(struct snd_timer_instance *timeri) list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head, open_list) { list_move_tail(&slave->open_list, &snd_timer_slave_list); + timer->num_instances--; slave->master = NULL; slave->timer = NULL; list_del_init(&slave->ack_list); @@ -376,14 +419,34 @@ int snd_timer_close(struct snd_timer_instance *timeri) timer->hw.close(timer); /* release a card refcount for safe disconnection */ if (timer->card) - put_device(&timer->card->card_dev); + *card_devp_to_put = &timer->card->card_dev; module_put(timer->module); } - mutex_unlock(®ister_mutex); return 0; } +/* + * close a timer instance + */ +int snd_timer_close(struct snd_timer_instance *timeri) +{ + struct device *card_dev_to_put = NULL; + int err; + + if (snd_BUG_ON(!timeri)) + return -ENXIO; + + mutex_lock(®ister_mutex); + err = snd_timer_close_locked(timeri, &card_dev_to_put); + mutex_unlock(®ister_mutex); + /* put_device() is called after unlock for avoiding deadlock */ + if (card_dev_to_put) + put_device(card_dev_to_put); + return err; +} +EXPORT_SYMBOL(snd_timer_close); + unsigned long snd_timer_resolution(struct snd_timer_instance *timeri) { struct snd_timer * timer; @@ -397,6 +460,7 @@ unsigned long snd_timer_resolution(struct snd_timer_instance *timeri) } return 0; } +EXPORT_SYMBOL(snd_timer_resolution); static void snd_timer_notify1(struct snd_timer_instance *ti, int event) { @@ -588,6 +652,7 @@ int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks) else return snd_timer_start1(timeri, true, ticks); } +EXPORT_SYMBOL(snd_timer_start); /* * stop the timer instance. @@ -601,6 +666,7 @@ int snd_timer_stop(struct snd_timer_instance *timeri) else return snd_timer_stop1(timeri, true); } +EXPORT_SYMBOL(snd_timer_stop); /* * start again.. the tick is kept. @@ -616,6 +682,7 @@ int snd_timer_continue(struct snd_timer_instance *timeri) else return snd_timer_start1(timeri, false, 0); } +EXPORT_SYMBOL(snd_timer_continue); /* * pause.. remember the ticks left @@ -627,6 +694,7 @@ int snd_timer_pause(struct snd_timer_instance * timeri) else return snd_timer_stop1(timeri, false); } +EXPORT_SYMBOL(snd_timer_pause); /* * reschedule the timer @@ -808,6 +876,7 @@ void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left) if (use_tasklet) tasklet_schedule(&timer->task_queue); } +EXPORT_SYMBOL(snd_timer_interrupt); /* @@ -846,6 +915,7 @@ int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, spin_lock_init(&timer->lock); tasklet_init(&timer->task_queue, snd_timer_tasklet, (unsigned long)timer); + timer->max_instances = 1000; /* default limit per timer */ if (card != NULL) { timer->module = card->module; err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops); @@ -858,6 +928,7 @@ int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, *rtimer = timer; return 0; } +EXPORT_SYMBOL(snd_timer_new); static int snd_timer_free(struct snd_timer *timer) { @@ -977,6 +1048,7 @@ void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstam } spin_unlock_irqrestore(&timer->lock, flags); } +EXPORT_SYMBOL(snd_timer_notify); /* * exported functions for global timers @@ -992,11 +1064,13 @@ int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer) tid.subdevice = 0; return snd_timer_new(NULL, id, &tid, rtimer); } +EXPORT_SYMBOL(snd_timer_global_new); int snd_timer_global_free(struct snd_timer *timer) { return snd_timer_free(timer); } +EXPORT_SYMBOL(snd_timer_global_free); int snd_timer_global_register(struct snd_timer *timer) { @@ -1006,6 +1080,7 @@ int snd_timer_global_register(struct snd_timer *timer) dev.device_data = timer; return snd_timer_dev_register(&dev); } +EXPORT_SYMBOL(snd_timer_global_register); /* * System timer @@ -2121,17 +2196,3 @@ static void __exit alsa_timer_exit(void) module_init(alsa_timer_init) module_exit(alsa_timer_exit) - -EXPORT_SYMBOL(snd_timer_open); -EXPORT_SYMBOL(snd_timer_close); -EXPORT_SYMBOL(snd_timer_resolution); -EXPORT_SYMBOL(snd_timer_start); -EXPORT_SYMBOL(snd_timer_stop); -EXPORT_SYMBOL(snd_timer_continue); -EXPORT_SYMBOL(snd_timer_pause); -EXPORT_SYMBOL(snd_timer_new); -EXPORT_SYMBOL(snd_timer_notify); -EXPORT_SYMBOL(snd_timer_global_new); -EXPORT_SYMBOL(snd_timer_global_free); -EXPORT_SYMBOL(snd_timer_global_register); -EXPORT_SYMBOL(snd_timer_interrupt); |