[alsa-devel] asoc SND_SOC_DAPM_AIF_IN question

Mark Brown broonie at opensource.wolfsonmicro.com
Fri Dec 24 12:35:58 CET 2010

On Thu, Dec 23, 2010 at 06:31:08PM +0530, Koul, Vinod wrote:

> > "Audio Supply" sounds like the main analogue bias for the CODEC - that
> > would normally be managed by set_bias_level() rather than by having it
> > supply every single widget in the CODEC map.

> Yes that would make sense. But only for Audio rail which is global codec rail.
> What do you recommend for headset and speaker rails? They would be required only for headset and speaker DAI not rest.

Supplies for them seem sensible.

> > If you have multiple links between the CPU and the CODEC with a single
> > power bit to control them all I'd suggest defining several AIF widgets,
> > each with no power management, then making the actual power controlled
> > by a supply widget.  That way the power will be enabled as required but
> > you won't have tied all the data streams together in the DAPM map.

> Okay so then why should I do with several AIF widgets, wont doing that in DAI startup be a better idea?

Doing things via data rather than with explicit code tends to be lower
maintainance; there's less potential for things to go wrong and it's
usually less work to keep up to date with API changes.

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