/* 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);
#endif
+/* move the slave if it belongs to the master; return 1 if match */
+static int check_matching_master_slave(struct snd_timer_instance *master,
+ struct snd_timer_instance *slave)
+{
+ if (slave->slave_class != master->slave_class ||
+ slave->slave_id != master->slave_id)
+ return 0;
+ 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;
+ slave->timer = master->timer;
+ if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
+ list_add_tail(&slave->active_list, &master->slave_active_head);
+ spin_unlock(&master->timer->lock);
+ spin_unlock_irq(&slave_active_lock);
+ return 1;
+}
+
/*
* look for a master instance matching with the slave id of the given slave.
* when found, relink the open_link of the slave.
{
struct snd_timer *timer;
struct snd_timer_instance *master;
+ int err = 0;
/* FIXME: it's really dumb to look up all entries.. */
list_for_each_entry(timer, &snd_timer_list, device_list) {
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 0;
- }
+ err = check_matching_master_slave(master, slave);
+ if (err != 0) /* match found or error */
+ goto out;
}
}
- return 0;
+ out:
+ return err < 0 ? err : 0;
}
/*
static int snd_timer_check_master(struct snd_timer_instance *master)
{
struct snd_timer_instance *slave, *tmp;
+ int err = 0;
/* check all pending slaves */
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;
- slave->timer = master->timer;
- if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
- list_add_tail(&slave->active_list,
- &master->slave_active_head);
- spin_unlock(&master->timer->lock);
- spin_unlock_irq(&slave_active_lock);
- }
+ err = check_matching_master_slave(master, slave);
+ if (err < 0)
+ break;
}
- return 0;
+ return err < 0 ? err : 0;
}
static int snd_timer_close_locked(struct snd_timer_instance *timeri,
err = -EINVAL;
goto unlock;
}
+ if (num_slaves >= MAX_SLAVE_INSTANCES) {
+ err = -EBUSY;
+ goto unlock;
+ }
timeri = snd_timer_instance_new(owner, NULL);
if (!timeri) {
err = -ENOMEM;
timeri->slave_id = tid->device;
timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
list_add_tail(&timeri->open_list, &snd_timer_slave_list);
+ num_slaves++;
err = snd_timer_check_slave(timeri);
if (err < 0) {
snd_timer_close_locked(timeri, &card_dev_to_put);
}
list_del(&timeri->open_list);
+ if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+ num_slaves--;
/* force to stop the timer */
snd_timer_stop(timeri);