[pulseaudio-discuss] ASoC and pulseaudio

[Tanu Kaskinen]

On Thu, 2016-02-18 at 14:58 +0530, Arun Raghavan wrote:
> On Thu, 2016-02-18 at 11:16 +0200, Tanu Kaskinen wrote:
> > On Thu, 2016-02-18 at 11:24 +0530, Arun Raghavan wrote:
> > > On Wed, 2016-02-17 at 16:27 +0100, Carlo Caione wrote:
> > > > Another possibility is to use UCM and let PA create automatically from
> > > > that profile and path configuration files. This looks promising but we
> > > > were a bit worried about the UCM support in PA and how stable/adopted
> > > > is UCM itself.
> > > > 
> > > > So, what is the suggested way to accomplish this and in general how PA
> > > > is trying to address this problem? I expect in the future to see many
> > > > more ASoC coming into the laptops world, how will the community make
> > > > it so that you install a distro and then sound "just works"?
> > > 
> > > If you are able to express what you need with UCM, it should be fine
> > > for your use case. ChromeOS uses it, and our support is meant to just
> > > work.
> > > 
> > > The idea thus far has been to collate UCM configuration that works with
> > > mainline kernel in a single ALSA repository, so that'd be the right
> > > place to put such config.
> > 
> > We lack hardware volume support with UCM, though. I promised last year
> > to Liam to implement it, maybe I should actually start doing something
> > about that... Software volume of course works fine too, but if
> > PulseAudio doesn't do hw volume control, the UCM file has to take that
> > into account and set the hw volume to a fixed value, which is not good
> > for interoperability with e.g. ChromeOS.
> 
> UCM supports "PlaybackVolume" and "CaptureVolume" properties. These
> only allow modifying volume via a single control, but changing more
> than that would likely require UCM-side changes.
> 
> I did implement support for these a while back:
> 
> https://cgit.freedesktop.org/~arun/pulseaudio/commit/?h=b2g&id=7d3a9f47
> 7cd2be83fd72bc25adf95bd49d1eb91f
> 
> I can potentially update that if it looks broadly useful.

It certainly does look useful.

-- 
Tanu