[alsa-devel] [PATCH] ALSA: hda - Mute all aamix inputs as default

[Takashi Iwai]

Not all channels have been initialized, so far, especially when aamix
NID itself doesn't have amps but its leaves have.  This patch fixes
these holes.  Otherwise you might get unexpected loopback inputs,
e.g. from surround channels.

Cc: <stable at vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/pci/hda/hda_generic.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c
index c4671d00babd..249cd4615908 100644
--- a/sound/pci/hda/hda_generic.c
+++ b/sound/pci/hda/hda_generic.c
@@ -4297,6 +4297,26 @@ static unsigned int snd_hda_gen_path_power_filter(struct hda_codec *codec,
 	return AC_PWRST_D3;
 }
 
+/* mute all aamix inputs initially; parse up to the first leaves */
+static void mute_all_mixer_nid(struct hda_codec *codec, hda_nid_t mix)
+{
+	int i, nums;
+	const hda_nid_t *conn;
+	bool has_amp;
+
+	nums = snd_hda_get_conn_list(codec, mix, &conn);
+	has_amp = nid_has_mute(codec, mix, HDA_INPUT);
+	for (i = 0; i < nums; i++) {
+		if (has_amp)
+			snd_hda_codec_amp_stereo(codec, mix,
+						 HDA_INPUT, i,
+						 0xff, HDA_AMP_MUTE);
+		else if (nid_has_volume(codec, conn[i], HDA_OUTPUT))
+			snd_hda_codec_amp_stereo(codec, conn[i],
+						 HDA_OUTPUT, 0,
+						 0xff, HDA_AMP_MUTE);
+	}
+}
 
 /*
  * Parse the given BIOS configuration and set up the hda_gen_spec
@@ -4435,6 +4455,10 @@ int snd_hda_gen_parse_auto_config(struct hda_codec *codec,
 		}
 	}
 
+	/* mute all aamix input initially */
+	if (spec->mixer_nid)
+		mute_all_mixer_nid(codec, spec->mixer_nid);
+
  dig_only:
 	parse_digital(codec);
 
-- 
1.8.5