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Commit 05ff7e11 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

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: default avatarTakashi Iwai <tiwai@suse.de>
parent 05e870d2

sound/pci/hda/hda_codec.c

+7 −2
Original line number Original line Diff line number Diff line
@@ -2367,9 +2367,14 @@ static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg, 
	hda_nid_t nid;

	hda_nid_t nid;

	int i;

	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);

			    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;

	nid = codec->start_nid;

	for (i = 0; i < codec->num_nodes; i++, nid++) {

	for (i = 0; i < codec->num_nodes; i++, nid++) {

sound/pci/hda/patch_sigmatel.c

+14 −0
Original line number Original line Diff line number Diff line
@@ -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)

static int stac92xx_suspend(struct hda_codec *codec, pm_message_t state)

{

{

	struct sigmatel_spec *spec = codec->spec;

	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)

	if (spec->eapd_mask)

		stac_gpio_set(codec, spec->gpio_mask,

		stac_gpio_set(codec, spec->gpio_mask,

				spec->gpio_dir, spec->gpio_data &

				spec->gpio_dir, spec->gpio_data &