diff options
| author | Takashi Iwai <tiwai@suse.de> | 2012-12-20 11:48:54 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2013-01-12 08:34:02 +0100 |
| commit | 47d46abba2d2046c6bfa37eeb583269d43e659ad (patch) | |
| tree | 64443d7b1be721820804768b150ccd02583098ae | |
| parent | 84e3908dc837b9d3314a92d8fda12a0ce3946714 (diff) | |
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>
| -rw-r--r-- | sound/pci/hda/hda_generic.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c index 3e818b6aa5b0..f5eb57cdac2d 100644 --- a/sound/pci/hda/hda_generic.c +++ b/sound/pci/hda/hda_generic.c @@ -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; |