[alsa-devel] Need help fixing pop/click artifacts in an ASOC driver

[Dimitris Papavasiliou]

On 12/13/18 7:42 PM, Mark Brown wrote:
> On Sat, Nov 24, 2018 at 10:17:49PM +0200, Dimitris Papavasiliou wrote:
> 
>> discussion here.  I still feel that fixing the machine driver, so
>> that it doesn't generate the pop at all would be desirable, as
>> I'm not sure whether the digital_mute callback is guaranteed to
>> have muted the device when the clock source takes place.
> 
> Making the machine driver more robust is definitely better, it's more
> robust in case the mute is for example just a very low gain which might
> still let the pop through at a lower level.

Even worse, it would let the pop through at full volume, as it
doesn't depend on the gain.  Still, there doesn't seem to be a
safe way to avoid the pop altogether, as far as I can see, since
the only way I have found to avoid it, is to suspend the chip
during the switch, and I can't synchronize access to the relevant
register by the machine and CODEC drivers.

If you have any other ideas/pointers on approaches I could
investigate, please let me know.