From 05ff7e11b78f18ff6819d2c260b7bcc7da0c8f46 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 22 Jul 2009 12:39:24 +0200 Subject: 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 --- sound/pci/hda/hda_codec.c | 9 +++++++-- sound/pci/hda/patch_sigmatel.c | 14 ++++++++++++++ 2 files changed, 21 insertions(+), 2 deletions(-) (limited to 'sound/pci') diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index d686f4fcd78..3ecb45ddadf 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -2367,9 +2367,14 @@ static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg, hda_nid_t nid; int i; - snd_hda_codec_write(codec, fg, 0, AC_VERB_SET_POWER_STATE, + /* this delay seems necessary to avoid click noise at power-down */ + if (power_state == AC_PWRST_D3) + msleep(100); + snd_hda_codec_read(codec, fg, 0, AC_VERB_SET_POWER_STATE, power_state); - msleep(10); /* partial workaround for "azx_get_response timeout" */ + /* partial workaround for "azx_get_response timeout" */ + if (power_state == AC_PWRST_D0) + msleep(10); nid = codec->start_nid; for (i = 0; i < codec->num_nodes; i++, nid++) { diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c index 41b5b3a18c1..00c702df721 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 & -- cgit v1.2.3