[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?

speaker-test -Dhw:0,0 -c4 -t wav

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda/patch_realtek.c?id=7cef4cf1c5e9d81554137f52b96a5ab7f6241cdd

You need to notify user of other acer aspire which use quirk
ALC888_ACER_ASPIRE_4930G if you want to remove node 0x16

> >>>
> >>>
> >
https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/plain/Documentation/sound/alsa/Channel-Mapping-API.txt
> >>> [1]
> >>>
> >>> seem chnmap type _FIXED , _VAR and _PAIRED does not fit when LFE and
> >>> FC can be swapped for internal speaker and external speaker
> >>
> >>
> >> Right, you can't do it with a single map of one of those types.
> >
> >
http://git.alsa-project.org/?p=alsa-utils.git&a=search&h=HEAD&st=commit&s=chmap
> >
> > do chmap of internal speakers need {FL FR RL RR LFE NA} ?
>
> From above it looks like there are 3 internal speakers, so I guess e.g.
> {FL FR LFE NA} might be in order (or just {FL FR LFE} if 3-channel
> playback is supported).

This is different from 2.1 internal speakers when yours also support
external 5.1

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda?id=f37bc7a88d374448a1f4bba9267d308606d78bf2

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda?id=8e38395360844806041ea69ab9690f5f174bc40c

>
> >
http://git.alsa-project.org/?p=alsa-utils.git;a=commitdiff;h=7b14c00b56784f69ecc954a2de36e0a058fc8849;hp=000bf230cfb3b0abe88d27701dd77982675126ec
> >
> > this example seem not working
> >
> > speaker-test -c2 -t wav -Dplug:front -mFR,FL
>
> You are getting an error?

Unable to set channel map

> If so, that is expected if the underlying device does not support the
> wanted channel map.
>

Seem only those idt codecs which wcaps support R/L swap but hda-intel use
snd_pcm_std_chmap

Are there any other sound card support swap front right and front left ?