[alsa-devel] [PATCH] ALSA: hda - Fix inverted internal mic not indicated on some machines

David Henningsson david.henningsson at canonical.com
Mon Oct 14 10:16:22 CEST 2013

The create_bind_cap_vol_ctl does not create any control indicating
that an inverted dmic is present. Therefore, create multiple
capture volumes in this scenario, so we always have some indication
that the internal mic is inverted.

This happens on the Lenovo Ideapad U310 as well as the Lenovo Yoga 13
(both are based on the CX20590 codec), but the fix is generic and
could be needed for other codecs/machines too.

Thanks to Szymon Acedański for the pointer and a draft patch.

BugLink: https://bugs.launchpad.net/bugs/1239392
BugLink: https://bugs.launchpad.net/bugs/1227491
Reported-by: Szymon Acedański <accek at mimuw.edu.pl>
Signed-off-by: David Henningsson <david.henningsson at canonical.com>
 sound/pci/hda/hda_generic.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

I think this fix is safe enough to send to Linus and stable, but will leave the
final judgement to Takashi.

diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c
index ac41e9c..26ad4f0 100644
--- a/sound/pci/hda/hda_generic.c
+++ b/sound/pci/hda/hda_generic.c
@@ -3531,7 +3531,7 @@ static int create_capture_mixers(struct hda_codec *codec)
 		if (!multi)
 			err = create_single_cap_vol_ctl(codec, n, vol, sw,
-		else if (!multi_cap_vol)
+		else if (!multi_cap_vol && !inv_dmic)
 			err = create_bind_cap_vol_ctl(codec, n, vol, sw);
 			err = create_multi_cap_vol_ctl(codec);

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