[alsa-devel] How to trigger a widget?

Wang, Kuirong kuirongw at quicinc.com
Fri Feb 24 05:57:40 CET 2012

On 02/21/2012 11:28 PM, Peter Ujfalusi  wrote:
>Would not it be simpler if you just enable/disable the feature in the kcontrol's set callback?
>Another way I would go is this:
>                  |-> (off) ---------|
>[Feature switch] -|                  |-> [next widget]
>                  |-> (on) -> [PGA] -|
>In the PGA you turn on/off the feature. If the switch changes it will not affect other items in the path, it will only make the PGA to turn on/off.


I don't want to power on this circuit related to the feature if the audio stream is not playing so if I use the kcontrol callback function to do so, it could power up even the audio stream is not playing. 

I will try the way you suggested by using a switch. In the meanwhile, I will check why the enable_pin doesn't work as expected in my system.



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