ALSA: vmaster - Free slave-links when freeing the master element

When freeing the vmaster master element, we should release slave-links
properly, not only assumig that slaves will be freed soon later.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
index 5dbab38..130cfe6 100644 (file)
--- a/sound/core/vmaster.c
+++ b/sound/core/vmaster.c
@@ -52,6 +52,7 @@ struct link_slave {
        struct link_ctl_info info;
        int vals[2];            /* current values */
        unsigned int flags;
+       struct snd_kcontrol *kctl; /* original kcontrol pointer */
        struct snd_kcontrol slave; /* the copy of original control entry */
 };
 
@@ -252,6 +253,7 @@ int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
                       slave->count * sizeof(*slave->vd), GFP_KERNEL);
        if (!srec)
                return -ENOMEM;
+       srec->kctl = slave;
        srec->slave = *slave;
        memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
        srec->master = master_link;
@@ -333,10 +335,18 @@ static int master_put(struct snd_kcontrol *kcontrol,
 static void master_free(struct snd_kcontrol *kcontrol)
 {
        struct link_master *master = snd_kcontrol_chip(kcontrol);
-       struct link_slave *slave;
-
-       list_for_each_entry(slave, &master->slaves, list)
-               slave->master = NULL;
+       struct link_slave *slave, *n;
+
+       /* free all slave links and retore the original slave kctls */
+       list_for_each_entry_safe(slave, n, &master->slaves, list) {
+               struct snd_kcontrol *sctl = slave->kctl;
+               struct list_head olist = sctl->list;
+               memcpy(sctl, &slave->slave, sizeof(*sctl));
+               memcpy(sctl->vd, slave->slave.vd,
+                      sctl->count * sizeof(*sctl->vd));
+               sctl->list = olist; /* keep the current linked-list */
+               kfree(slave);
+       }
        kfree(master);
 }