[alsa-devel] Front speakers doesn't work in multichannel output, regression in ALC888

[Raymond Yau]

>
> My problem is that when I set channel output to "Analog output surround
5.1"
> (or 2.1 or 4.1), I hear no sound in front speakers, but in case of 5.1 or
4.1
> I can hear sound in rear speakers. I use kernel 3.19.5 and it didn't
happen in
> earlier kernels that is 3.18 and in 3.17 for sure.
>
> My configuration is:
> OS: Fedora 21 64 bit
> SoundCard: ALC888
> Model name: acer-aspire-4930g
> Laptop: Acer Aspire 5930g
> Speakers: external 5.1 with 3 jacks
> Sound channel configuration module is standard configuration module from
KDE.
>
> Additional info:
> 1) When channel output is 5.1 and I unplug green jack and leave two others
> jacks connected then I can hear sound in laptop internal speakers.
> 2) Earlier (kernel 3.18 and 3.17) I didn't have possibility to choose 2.1
> configuration and additionally to 4.1 configuration I could also choose
4.0
> configuration.

You have to provide pulseaudio verbose log

If driver create channel mode which allow you to support surround5.1 with
your headphone,  line in and mic jack

It is possible for pulseaudio mute two of your external 5.1 speaker when
headphone jack is plugged

http://cgit.freedesktop.org/pulseaudio/pulseaudio/tree/src/modules/alsa/mixer/paths/analog-output-headphones.conf

[Element Rear]
switch = off
volume = off

[Element Surround]
switch = off
volume = off

[Element Center]
switch = off
volume = off

[Element LFE]
switch = off
volume = off