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

[Raymond Yau]

> I started MS Windows and without externals speakers plugged in I could
test
> 5.1 configuration and it seemed that sound was coming from different
directions.

>
> What I managed to determine:
> I've got 3 stacks:
> 1 ST: Headphone, Line-out (FL and FR), SPDIF
> 2 ST: Microphone, Line-out (CLFE)
> 3 ST: Line-in, Line-out (RL and RR)
>
> I've got 5 responsive output pins
> PIN 0x14: Internal FL FR
> PIN 0x15: External FL FR
> PIN 0x17: Internal LFE
> PIN 0x18: External CLFE
> PIN 0x1a: External RL RR
>
> How can we make it work with these information?

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/plain/Documentation/sound/alsa/Channel-Mapping-API.txt

seem chnmap type _FIXED , _VAR and _PAIRED does not fit when LFE and FC can
be swapped for internal speaker and external speaker

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda?id=0fb87bb474f978446786263deff6263284e6e011

How do the driver implement channel map when codec has  swap center/lfe
switch ?

Do chnmap contain both {FL FR RL RR FC LFE} and {FL FR RL RR LFE FC} ?

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda?id=5a61358433b1f89b500f2c365746c73cb7a27e2f

atihdmi_paired_swap_fc_lfe