Commit ebfc6de2 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: timer: Unify master/slave linking code 



The code in both snd_timer_check_master() and snd_timer_check_slave()
are almost identical, both check whether the master/slave link and
does linkage.  Factor out the common code and call it from both
functions for readability.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20191107192008.32331-2-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 66a8966a

sound/core/timer.c

+33 −33
Original line number Diff line number Diff line
@@ -163,6 +163,28 @@ static void snd_timer_request(struct snd_timer_id *tid) 


#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.
@@ -173,27 +195,18 @@ static int snd_timer_check_slave(struct snd_timer_instance *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;

}



/*
@@ -205,28 +218,15 @@ static int snd_timer_check_slave(struct snd_timer_instance *slave) 
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,

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