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authorTakashi Iwai <tiwai@suse.de>2009-01-16 18:15:22 +0100
committerTakashi Iwai <tiwai@suse.de>2009-03-09 14:56:19 +0100
commitf5b1db634280ecaf3147ee996f26aad0ed4828c4 (patch)
treece7ba0940e5dd3f106276d9119f7e7e3a3b0c7e6 /sound/core
parentfec6c6fec3e20637bee5d276fb61dd8b49a3f9cc (diff)
downloadlinux-f5b1db634280ecaf3147ee996f26aad0ed4828c4.tar.bz2
ALSA: add snd_ctl_add_slave_uncached()
Added snd_ctl_add_slave_uncached() function to add a slave element with volatile controls. The values of normal slave elements are supposed to be cachable, i.e. they are changed only via the put callbacks. OTOH, when a slave element is volatile and its values may be changed by other reason (e.g. hardware status change), the values will get inconsistent. The new function allows the slave elements with volatile changes. When the slave is tied with this call, the native get callback is issued at each time so that the values are always updated. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/vmaster.c46
1 files changed, 29 insertions, 17 deletions
diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
index 4cc57f902e2c..d51b198d06d9 100644
--- a/sound/core/vmaster.c
+++ b/sound/core/vmaster.c
@@ -50,18 +50,38 @@ struct link_slave {
struct link_master *master;
struct link_ctl_info info;
int vals[2]; /* current values */
+ unsigned int flags;
struct snd_kcontrol slave; /* the copy of original control entry */
};
+static int slave_update(struct link_slave *slave)
+{
+ struct snd_ctl_elem_value *uctl;
+ int err, ch;
+
+ uctl = kmalloc(sizeof(*uctl), GFP_KERNEL);
+ if (!uctl)
+ return -ENOMEM;
+ uctl->id = slave->slave.id;
+ err = slave->slave.get(&slave->slave, uctl);
+ for (ch = 0; ch < slave->info.count; ch++)
+ slave->vals[ch] = uctl->value.integer.value[ch];
+ kfree(uctl);
+ return 0;
+}
+
/* get the slave ctl info and save the initial values */
static int slave_init(struct link_slave *slave)
{
struct snd_ctl_elem_info *uinfo;
- struct snd_ctl_elem_value *uctl;
- int err, ch;
+ int err;
- if (slave->info.count)
- return 0; /* already initialized */
+ if (slave->info.count) {
+ /* already initialized */
+ if (slave->flags & SND_CTL_SLAVE_NEED_UPDATE)
+ return slave_update(slave);
+ return 0;
+ }
uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
if (!uinfo)
@@ -85,15 +105,7 @@ static int slave_init(struct link_slave *slave)
slave->info.max_val = uinfo->value.integer.max;
kfree(uinfo);
- uctl = kmalloc(sizeof(*uctl), GFP_KERNEL);
- if (!uctl)
- return -ENOMEM;
- uctl->id = slave->slave.id;
- err = slave->slave.get(&slave->slave, uctl);
- for (ch = 0; ch < slave->info.count; ch++)
- slave->vals[ch] = uctl->value.integer.value[ch];
- kfree(uctl);
- return 0;
+ return slave_update(slave);
}
/* initialize master volume */
@@ -229,7 +241,8 @@ static void slave_free(struct snd_kcontrol *kcontrol)
* - logarithmic volume control (dB level), no linear volume
* - master can only attenuate the volume, no gain
*/
-int snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
+int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
+ unsigned int flags)
{
struct link_master *master_link = snd_kcontrol_chip(master);
struct link_slave *srec;
@@ -241,6 +254,7 @@ int snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
srec->slave = *slave;
memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
srec->master = master_link;
+ srec->flags = flags;
/* override callbacks */
slave->info = slave_info;
@@ -254,8 +268,7 @@ int snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
list_add_tail(&srec->list, &master_link->slaves);
return 0;
}
-
-EXPORT_SYMBOL(snd_ctl_add_slave);
+EXPORT_SYMBOL(_snd_ctl_add_slave);
/*
* ctl callbacks for master controls
@@ -367,5 +380,4 @@ struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
return kctl;
}
-
EXPORT_SYMBOL(snd_ctl_make_virtual_master);