[alsa-devel] [RFC] ASoC: multi-component: Add optional kcontrol prefix name for a DAI link

Mark Brown broonie at opensource.wolfsonmicro.com
Tue Aug 24 12:10:32 CEST 2010

On Tue, Aug 24, 2010 at 10:23:43AM +0300, Jarkko Nikula wrote:
> Mark Brown <broonie at opensource.wolfsonmicro.com> wrote:

> > Best not in the header; these are not things individual drivers should
> > be worrying their pretty little heads about.  If they should be used by
> > individual drivers then we need better names than just _.

> Yeah, I picked up _ prefix so that name indicates that these functions
> are more like for internal use and drivers should use them only
> exceptionally. What I'm thinking if we can rid of them completely.

I figured.

> From your commit 26b01cc it looks like there's a work in progress to
> support DAI-less codecs/amplifiers. If that would be possible then
> there is no need to register controls from other drivers in machine DAI

DAIless devices should work already.

> init. Well, CPU DAI controls are possible but they don't need a prefix
> I think.

There might be an issue disambiguating against collisions with other
drivers in the system, I guess.

> > I don't see how a DAI link can ever be used to configure prefix names -
> > there's just not any real association between DAI links and controls,
> > and as soon as you hit mixing any that does exist gets lost.  Probably a
> > table of CODEC to prefix mappings would be better.

> Sorry, I didn't emphasis this well enough that this hack was
> temporary just after your comment to first version and it got finally
> removed in yesterday's version :-)

Yeah, I was writing my reply as you sent that.

> > This one is a bit more fun.  For this to work properly we need to
> > consider what happens with the cross-device links in the DAI maps which
> > means we need to able to cope with separate prefixes for the source and
> > the sink.

> Prefixing is not problem I think since we can specify them in
> machine's audio map (like two mono amplifiers registered to 1st codec
> are prefixed below) but how to link DAPMs of two codec together?

We'll be fine just using the prefixed name in the machine drivers I
think and not advertising the prefix-adding route add function.

More information about the Alsa-devel mailing list