[PATCH] ALSA: hda/realtek - Keep analog bypass muted on ALC892

[Thierry Reding <thierry.reding@avionic-design.de>]

Unmuting the analog bypass causes any input to be directly bypassed to
the outputs, which is usually not expected by the user.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
---
Note that this patch could be generalized to include all codec variants
that have this second channel. As I don't have access to all the data
sheets I'll leave that decision up to somebody with more hardware
available.

 sound/pci/hda/patch_realtek.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 4f81dd4..54d0917 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -3752,8 +3752,15 @@ static void alc_auto_set_output_and_unmute(struct hda_codec *codec,
 	if (nid_has_mute(codec, mix, HDA_INPUT)) {
 		snd_hda_codec_write(codec, mix, 0, AC_VERB_SET_AMP_GAIN_MUTE,
 			    AMP_IN_UNMUTE(0));
-		snd_hda_codec_write(codec, mix, 0, AC_VERB_SET_AMP_GAIN_MUTE,
-			    AMP_IN_UNMUTE(1));
+		/*
+		 * On ALC892, the second entry in the connection list is the
+		 * analog bypass. Unmuting it will cause any inputs to be
+		 * directly forwarded to the corresponding outputs.
+		 */
+		if (codec->subsystem_id != 0x10ec0892)
+			snd_hda_codec_write(codec, mix, 0,
+					    AC_VERB_SET_AMP_GAIN_MUTE,
+					    AMP_IN_UNMUTE(1));
 	}
 	/* initialize volume */
 	nid = alc_look_for_out_vol_nid(codec, pin, dac);
-- 
1.7.11.4