tree dc227300fe1fa38dfd66a8fdec17ac611b0c868a
parent b43d224767e426cf1a8b6622d1d172f2b2b0e857
author Takashi Iwai <tiwai@suse.de> 1340368229 +0200
committer Takashi Iwai <tiwai@suse.de> 1340610354 +0200

ALSA: hda - Add the inverted digital mic workaround to Realtek codecs

Some laptops are equipped with ForteMedia digital mics that give the
differential input.  With such devices, summing stereo streams into a
mono (like PulseAudio does) results in almost silence.

This patch provides a workaround for this bug by adding a new mixer
switch to turn on/off the right channel of digital mic, just like a
similar fix for Conexant codecs.

When the new switch "Inverted Internal Mic Capture Switch" is off and
the current input source is the digital mic, the right channel of the
recording stream is muted.  When another input source is selected, the
right channel is restored.

Tested-by: Eliot Blennerhassett <eliot@blennerhassett.gen.nz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>