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Diffstat (limited to 'sound/core/timer.c')
-rw-r--r--sound/core/timer.c67
1 files changed, 54 insertions, 13 deletions
diff --git a/sound/core/timer.c b/sound/core/timer.c
index 6cdd04a45962..15e82a656d96 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -180,7 +180,7 @@ 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;
@@ -190,16 +190,21 @@ 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;
}
/*
@@ -208,7 +213,7 @@ 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;
@@ -216,7 +221,11 @@ 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;
@@ -228,8 +237,11 @@ 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);
+
/*
* open a timer instance
* when opening a master, the slave id must be here given.
@@ -240,6 +252,7 @@ int snd_timer_open(struct snd_timer_instance **ti,
{
struct snd_timer *timer;
struct snd_timer_instance *timeri = NULL;
+ int err;
if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
/* open a slave instance */
@@ -259,10 +272,14 @@ int snd_timer_open(struct snd_timer_instance **ti,
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);
+ err = snd_timer_check_slave(timeri);
+ if (err < 0) {
+ snd_timer_close_locked(timeri);
+ timeri = NULL;
+ }
mutex_unlock(&register_mutex);
*ti = timeri;
- return 0;
+ return err;
}
/* open a master instance */
@@ -288,6 +305,10 @@ int snd_timer_open(struct snd_timer_instance **ti,
return -EBUSY;
}
}
+ if (timer->num_instances >= timer->max_instances) {
+ mutex_unlock(&register_mutex);
+ return -EBUSY;
+ }
timeri = snd_timer_instance_new(owner, timer);
if (!timeri) {
mutex_unlock(&register_mutex);
@@ -314,25 +335,27 @@ int snd_timer_open(struct snd_timer_instance **ti,
}
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);
+ timeri = NULL;
+ }
mutex_unlock(&register_mutex);
*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 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);
/* force to stop the timer */
@@ -340,6 +363,7 @@ int snd_timer_close(struct snd_timer_instance *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) {
@@ -355,6 +379,7 @@ 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);
@@ -382,9 +407,24 @@ int snd_timer_close(struct snd_timer_instance *timeri)
module_put(timer->module);
}
- mutex_unlock(&register_mutex);
return 0;
}
+
+/*
+ * close a timer instance
+ */
+int snd_timer_close(struct snd_timer_instance *timeri)
+{
+ int err;
+
+ if (snd_BUG_ON(!timeri))
+ return -ENXIO;
+
+ mutex_lock(&register_mutex);
+ err = snd_timer_close_locked(timeri);
+ mutex_unlock(&register_mutex);
+ return err;
+}
EXPORT_SYMBOL(snd_timer_close);
unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
@@ -856,6 +896,7 @@ 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);
generated by cgit (git 2.34.1) at 2024-05-03 17:43:09 +0000