Re: [PATCH 1/6] ASoC: codecs: wsa884x: remove mute_unmute_on_trigger

[Jonathan Marek]

On 11/24/25 9:08 AM, Srinivas Kandagatla wrote:
> On 11/24/25 6:45 AM, Jonathan Marek wrote:
> > trigger is atomic (non-schedulable), and soundwire register writes are not
> > safe to run in an atomic context. (bus is locked with a mutex, and qcom
> > driver's callback can also sleep if the FIFO is full).
> Thanks Jonathan for the patch,
>
> We have nonatomic=1 flag set for all the Qualcomm sound cards, Did you
> hit any schedule while atomic bug?

Right, I missed that. I'm using a different driver which does not set 
nonatomic. But this driver to not need nonatomic - 
mute_unmute_on_trigger is a hack, if there is a timing requirement - 
then it needs to be explicit, the different timing with this flag is not 
reliable).

> In-fact this change has helped suppress most of the click and pop noises
> on laptops, specially with wsa codecs as they accumulate static if the
> ports are kept open without sending any data.

28b0b18d5346 is important to fix the click and pop noises. But the 
useful part is the rest of the commit, not the mute_unmute_on_trigger 
flag. As long as the mute_stream() happens while the soundwire stream is 
enabled (between sdw_enable_stream and sdw_disable_stream), there should 
be no pop click.

AFAIK the pop/click is because of PDM: zeros (soundwire stream off) 
represent the minimum (negative maximum) amplitude, and the soundwire 
stream needs to be enabled to output a zero amplitude (alternating 
ones/zeros). Turning on the amp while the soundwire stream is not 
enabled will cause jumps between the minimum and zero amplitude.

> --srini
>
>
> > The important part of fixing the click/pop issue was removing the PA_EN
> > writes from the dapm events, AFAICT this flag doesn't help anyway.
> >
> > Fixes: 28b0b18d5346 ("ASoC: codec: wsa884x: make use of new mute_unmute_on_trigger flag")
> > Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
> > ---
> >   sound/soc/codecs/wsa884x.c | 1 -
> >   1 file changed, 1 deletion(-)
> >
> > diff --git a/sound/soc/codecs/wsa884x.c b/sound/soc/codecs/wsa884x.c
> > index 2484d4b8e2d94..0218dfc13bc77 100644
> > --- a/sound/soc/codecs/wsa884x.c
> > +++ b/sound/soc/codecs/wsa884x.c
> > @@ -1840,7 +1840,6 @@ static const struct snd_soc_dai_ops wsa884x_dai_ops = {
> >   	.hw_free = wsa884x_hw_free,
> >   	.mute_stream = wsa884x_mute_stream,
> >   	.set_stream = wsa884x_set_stream,
> > -	.mute_unmute_on_trigger = true,
> >   };
> >   
> >   static struct snd_soc_dai_driver wsa884x_dais[] = {