diff options
| author | Takashi Iwai <tiwai@suse.de> | 2009-07-22 12:39:24 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-07-22 12:39:24 +0200 |
| commit | 05ff7e11b78f18ff6819d2c260b7bcc7da0c8f46 (patch) | |
| tree | d19b9ea9530321a0513863ccd32cf5f3f3f3e343 /sound/pci/hda/patch_sigmatel.c | |
| parent | 05e870d29aef0bf43124b2bd424103987fadd5b5 (diff) | |
ALSA: hda - Reduce click noise at power-saving
Add some tricks to reduce the click noise at powering down to D3
in the power saving mode on STAC/IDT codecs.
The key seems to be to reset PINs before the power-down, and some
delay before entering D3. The needed delay is significantly long,
but I don't know why.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/pci/hda/patch_sigmatel.c')
| -rw-r--r-- | sound/pci/hda/patch_sigmatel.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c index 41b5b3a18c1e..00c702df721c 100644 --- a/sound/pci/hda/patch_sigmatel.c +++ b/sound/pci/hda/patch_sigmatel.c @@ -4745,6 +4745,20 @@ static int stac92xx_hp_check_power_status(struct hda_codec *codec, static int stac92xx_suspend(struct hda_codec *codec, pm_message_t state) { struct sigmatel_spec *spec = codec->spec; + int i; + hda_nid_t nid; + + /* reset each pin before powering down DAC/ADC to avoid click noise */ + nid = codec->start_nid; + for (i = 0; i < codec->num_nodes; i++, nid++) { + unsigned int wcaps = get_wcaps(codec, nid); + unsigned int wid_type = (wcaps & AC_WCAP_TYPE) >> + AC_WCAP_TYPE_SHIFT; + if (wid_type == AC_WID_PIN) + snd_hda_codec_read(codec, nid, 0, + AC_VERB_SET_PIN_WIDGET_CONTROL, 0); + } + if (spec->eapd_mask) stac_gpio_set(codec, spec->gpio_mask, spec->gpio_dir, spec->gpio_data & |