[Freedreno] hdmi audio on ifc6410

[Rob Clark]

On Thu, Dec 12, 2013 at 11:11 AM, Rob Clark <robdclark at gmail.com> wrote:
> On Wed, Dec 11, 2013 at 8:08 PM, Rob Clark <robdclark at gmail.com> wrote:
>> fyi, I've managed to get hdmi audio (mostly) working, on the inforce
>> board.  I expect that basically the same thing should work on bstem as
>> well.
>>
>> I've untangled the msm alsa/soc driver from ION and fixed a few issues
>> with it along the way.  What I have is still a bit work-in-progress,
>> but I've pushed to here:
>>
>>   https://github.com/freedreno/kernel-msm/commits/ifc6410-drm-hdmi-audio
>>   git://github.com/freedreno/kernel-msm.git ifc6410-drm-hdmi-audio
>>
>> (and may I add, the sound/soc/msm stuff is a royal PITA to debug!)
>>
>> There are a couple rough edges:
>>
>> 1) Shows up as 'Analog Output' in gnome sound control panel.. I'm not
>> much of an audio expert but I think this is a symptom of pulseaudio
>> not properly recognizing things.  Maybe we need some pulseaudio config
>> files so that it properly understands the audio routing options?
>
> fwiw, it seems like what we need is UCM config:
>
> http://www.alsa-project.org/main/index.php/Use_Case_Manager
>
> looks like pulseaudio already supports UCM, so I think once we get the
> proper UCM config so that userspace can properly understand all the
> audio routing/mixing options, things should just work:
>
> http://www.freedesktop.org/wiki/Software/PulseAudio/Notes/3.0/

(so, partially just so I don't loose the link), it looks like ubuntu
touch folks have partially created UCM config for us:

http://bazaar.launchpad.net/~ubuntu-audio-dev/alsa-lib/ubuntu/revision/170

looks like it is missing hdmi audio path, but I guess that should be a
reasonable starting point


> BR,
> -R
>
>> 2) Glitch at beginning of playback.. probably I need to do something
>> to synchronize w/ audio engine before enabling audio packets on the
>> hdmi side of things.  Need to sort out how that works.
>>
>>
>> for folks who want to try it out, I've also put a pre-built kernel here:
>>
>>   http://people.freedesktop.org/~robclark/f20/ifc6410-boot-audio.img
>>
>> and my alsa config:
>>
>>   http://people.freedesktop.org/~robclark/f20/asound-hdmi.state
>>
>> to apply my config on your board:
>>
>>   sudo alsactl restore -f asound-hdmi.state
>>
>> If you know anything about SoC audio + pulseaudio, I could certainly
>> use some help sorting out the audio configuration/routing mess.. it's
>> something pretty far outside of my area of expertise.
>>
>> BR,
>> -R