[alsa-devel] [PATCH] ASoC: twl6040: Workaround for headset DC offset caused pop noise

Péter Ujfalusi peter.ujfalusi at ti.com
Wed Oct 12 10:55:15 CEST 2011

On Wednesday 12 October 2011 11:18:50 Péter Ujfalusi wrote:
> > This sounds like you should be using a supply widget to do the reference
> > counting here?
> Probably it is better to move the whole thing to be handled by a supply
> widget (attached to the HS DACs).
> It will not mess up the sequence, and I'm not going to need to count in the
> driver.
> Will rewrite the patch.

I can not move the HS DAC power on/off to be handled by a supply widget...
Refcounting in a supply widget will not work for the power down, since the 
supply widget will be turned off after the DAC widget. At time when the DAC 
receives the PMD event the attached supply is still on.
I can update the commit message to explicitly say that we need to turn on both 
HS DAC at the same time, and we need to turn tem off at the same time.


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