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Diffstat (limited to 'sound/core/timer.c')
-rw-r--r--sound/core/timer.c155
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(&register_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(&register_mutex);
timeri = snd_timer_instance_new(owner, NULL);
if (!timeri) {
- mutex_unlock(&register_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(&register_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(&register_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(&register_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(&register_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(&register_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(&register_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(&register_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(&register_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(&register_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(&register_mutex);
+ err = snd_timer_close_locked(timeri, &card_dev_to_put);
+ mutex_unlock(&register_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);
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-02 02:08:52 +0000