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>
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@ -2367,9 +2367,14 @@ static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
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hda_nid_t nid;
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int i;
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snd_hda_codec_write(codec, fg, 0, AC_VERB_SET_POWER_STATE,
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/* this delay seems necessary to avoid click noise at power-down */
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if (power_state == AC_PWRST_D3)
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msleep(100);
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snd_hda_codec_read(codec, fg, 0, AC_VERB_SET_POWER_STATE,
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power_state);
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msleep(10); /* partial workaround for "azx_get_response timeout" */
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/* partial workaround for "azx_get_response timeout" */
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if (power_state == AC_PWRST_D0)
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msleep(10);
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nid = codec->start_nid;
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for (i = 0; i < codec->num_nodes; i++, nid++) {
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@ -4745,6 +4745,20 @@ static int stac92xx_hp_check_power_status(struct hda_codec *codec,
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static int stac92xx_suspend(struct hda_codec *codec, pm_message_t state)
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{
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struct sigmatel_spec *spec = codec->spec;
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int i;
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hda_nid_t nid;
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/* reset each pin before powering down DAC/ADC to avoid click noise */
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nid = codec->start_nid;
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for (i = 0; i < codec->num_nodes; i++, nid++) {
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unsigned int wcaps = get_wcaps(codec, nid);
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unsigned int wid_type = (wcaps & AC_WCAP_TYPE) >>
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AC_WCAP_TYPE_SHIFT;
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if (wid_type == AC_WID_PIN)
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snd_hda_codec_read(codec, nid, 0,
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AC_VERB_SET_PIN_WIDGET_CONTROL, 0);
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}
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if (spec->eapd_mask)
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stac_gpio_set(codec, spec->gpio_mask,
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spec->gpio_dir, spec->gpio_data &
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