[PATCH alsa-lib 0/5] Add generic exception mechanism for non-standard control-names

[Hans de Goede]

Hi Jaroslav,

On 5/18/21 6:16 PM, Jaroslav Kysela wrote:
> Dne 04. 05. 21 v 17:47 Hans de Goede napsal(a):
>> Hi Jaroslav,
>>
>> On 5/4/21 10:53 AM, Jaroslav Kysela wrote:
>>> Dne 03. 05. 21 v 22:52 Hans de Goede napsal(a):
>>>> Hi All,
>>>>
>>>> This series seems to have fallen through the cracks,
>>>> so here is a resend of it.
>>>>
>>>> Regards,
>>>
>>> Thank you, Hans. The problem with this implementation is that it's really card
>>> specific. Also, ASoC codec drivers have usually ID names based on registers so
>>> the mapping for the user is problematic anyway (the functionality is different
>>> from the name or not related to the name). I'm actually evaluating another
>>> solution which is more flexible:
>>>
>>> 1) add control remap plugin to allow the control ID remapping in the
>>> alsa-lib's control API, so we can mangle those identifiers there (already
>>> implemented)
>>>
>>> 2) add local and global alsa-lib configurations per UCM card specified in the
>>> UCM configuration files; the configurations may be for both control and PCM
>>> devices (restrict or set specific parameters)
>>
>> Ok, thank you for working on this.
>>
>>> I will notify you when I finish my tests.
>>
>> Yes, please let me know when you've something ready to test, then I'll take
>> a look at adding the necessary bits for the bycr-rt5640 and cht-bsw-rt567
>> UCM profiles, as some control renaming is necessary to make sure that
>> the hw-volume control on these devices also correctly controls the
>> hw mute controls (which in turn are necessary for both full muting and
>> for mute LED control).
> 
> It seems that things started to work. I pushed everything to the repos
> (alsa-lib/alsa-utils/alsa-ucm-conf) and picked bits from your configs. If you
> can give a look and a test, it would be nice. The changes for the specific
> codecs are quite straight like:
> 
> https://github.com/alsa-project/alsa-ucm-conf/commit/2072ab794b69cdf4f070db5467387d08a65c4309
> 
> The global alsa-lib's configuration does the redirects to the hw specific
> configs (if found) per card. UCM can store this "per card" configuration to
> /var/lib/alsa/card<NUMBER>.conf.d tree, which allows us to define the hw
> specific configuration. Both control and PCM devices can be (re)configured.
> 
> UCM was extended to allow inline the alsa-lib's configuration which can be
> private to UCM or saved to a global config file (/var/lib/alsa tree for example).
> 
> By default, I made the private alsa-lib's configuration for all UCM
> applications, so the users cannot break UCM with their configuration changes.

Thank you for your work on this.

I've been testing this on a HP x2 Bay Trail + rt5640 laptop, and I've
found 2 issues:

1. After renaming there are now 2 "Speaker" and "Headphones" switches:

"Speaker Playback Volume" stays    "Speaker Playback Volume"
"Speaker Channel Switch"  becomes  "Speaker Playback Switch"
"Speaker Switch"          stays    "Speaker Switch"

And then alsamixer only shows one of the 2 "Speaker [Playback] Switches"

This can be worked around by changing the renames to e.g. :

                "name='HP Playback Volume'" "name='Headphones Playback Volume'"
                "name='HP Channel Switch'" "name='Headphones Playback Switch'"
                "name='Speaker Playback Volume'" "name='Speakers Playback Volume'"
                "name='Speaker Channel Switch'" "name='Speakers Playback Switch'"

Or to:

                # Rename the 'Headphone Switch' DAPM PIN switch to avoid it getting
                # grouped with 'Headphone Playback Volume'
                "name='Headphone Switch'" "name='Headphone Output Switch'"
                "name='HP Playback Volume'" "name='Headphone Playback Volume'"
                "name='HP Channel Switch'" "name='Headphone Playback Switch'"
                # Idem for the 'Speaker Switch'
                "name='Speaker Switch'" "name='Speaker Output Switch'"
                "name='Speaker Channel Switch'" "name='Speaker Playback Switch'"

So this is not really an issue.

2. PlaybackMixerElem statements don't take the renames into account, this means
that muting the speakers or the headphones output the UCM (pipewire/pulse) level
does not mute the 'Speaker Channel Switch' / 'HP Channel Switch' control, meaning
that we are not muting things at the hw level, which in turn is causing the speaker
mute LED on the HP X2 to not be turned on when muting.

I guess the fix here would be to make the renames apply to PlaybackMixerElem ?

Downside is that that would be a syntax change for the UCM conf language I guess
(e.g. this would require update the PlaybackMixerElem from HP to Headphone in the
rt5640 case)

If you can steer me in the right direction for fixing this I can take a shot at
fixing this. Or alternatively I would be happy to test any patches for this from
you.

Regards,

Hans