[alsa-devel] [PATCH] asoc tlv320aic3x: set power bits correctly

Jarkko Nikula jhnikula at gmail.com
Wed Apr 30 13:50:43 CEST 2008


On Wed, Apr 30, 2008 at 12:57 PM, Mark Brown <
broonie at opensource.wolfsonmicro.com> wrote:

>
> If what you're trying to do is avoid powering on amplifiers when they
> are muted then this is best avoided since it often creates problems with
> pops and clicks due to things getting powered on and off out of the
> sequence generated by DAPM.  If the amplifier is powered on before its
> inputs then it will amplify any noise generaetd by the inputs when they
> change power state.  This is why ASoC mute controls for amplifiers are
> normally independent of their power controls.
>

I was looking do we have possible driver bug here and answer is no. Driver
keeps output state powered during playback if associated endpoint is enabled
with snd_soc_dapm_set_endpoint and unpowered otherwise.

So as with Mark's comment, the patch is unnecessary.


Jarkko


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