ALSA: hda - Add / fix comments about capture vol/sw controls in hda_generic.c

A bit of details won't hurt.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2012-12-20 11:48:54 +01:00
parent 84e3908dc8
commit 47d46abba2
1 changed files with 10 additions and 5 deletions

View File

@ -1877,10 +1877,6 @@ static int mux_enum_put(struct snd_kcontrol *kcontrol,
ucontrol->value.enumerated.item[0]);
}
/*
* capture volume and capture switch ctls
*/
static const struct snd_kcontrol_new cap_src_temp = {
.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
.name = "Input Source",
@ -1889,9 +1885,14 @@ static const struct snd_kcontrol_new cap_src_temp = {
.put = mux_enum_put,
};
/*
* capture volume and capture switch ctls
*/
typedef int (*put_call_t)(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol);
/* call the given amp update function for all amps in the imux list at once */
static int cap_put_caller(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol,
put_call_t func, int type)
@ -1905,6 +1906,10 @@ static int cap_put_caller(struct snd_kcontrol *kcontrol,
imux = &spec->input_mux;
adc_idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
mutex_lock(&codec->control_mutex);
/* we use the cache-only update at first since multiple input paths
* may shared the same amp; by updating only caches, the redundant
* writes to hardware can be reduced.
*/
codec->cached_write = 1;
for (i = 0; i < imux->num_items; i++) {
path = snd_hda_get_nid_path(codec, spec->imux_pins[i],
@ -1919,7 +1924,7 @@ static int cap_put_caller(struct snd_kcontrol *kcontrol,
error:
codec->cached_write = 0;
mutex_unlock(&codec->control_mutex);
snd_hda_codec_flush_amp_cache(codec);
snd_hda_codec_flush_amp_cache(codec); /* flush the updates */
if (err >= 0 && spec->cap_sync_hook)
spec->cap_sync_hook(codec);
return err;