RE: [PATCH v3] ASoC: rt286: fix headphone click/crack noise on Dell XPS 9343 I2S mode

From: Bard Liao
Date: Tue Mar 21 2017 - 05:16:06 EST


> -----Original Message-----
> From: Kai-Heng Feng [mailto:kai.heng.feng@xxxxxxxxxxxxx]
> Sent: Tuesday, March 21, 2017 1:26 PM
> To: Mark Brown
> Cc: Liam Girdwood; Bard Liao; Oder Chiou; alsa-devel@xxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3] ASoC: rt286: fix headphone click/crack noise on Dell
> XPS 9343 I2S mode
> >
> >> I had the same thought originally, but printk under each case suggests
> >> otherwise - _POST_PMU is triggered not right after _PRE_PMU but right
> >> before _PRE_PMD.
> >
> > Then you've broken something else on your system, that is obviously
> > completely nonsensical and would break anything that relies on having a
> > _POST_PMU event. Why would we have two events that run at the same
> time
> > one of which is obviously misnamed?
>
> Hmm, that's weird though. I did the same test to rt286_spk_event()
> (without applying the patch I sent), what I observed was the same:
> _POST_PMU was triggered right after I stopped play sound, i.e. right
> before _PRE_PMD not right after _PRE_PMU.
>

Although I don't think it will happen on my side, but I still
ran the same test as you. The result is just as what we
expected, _PRE_PMU and _POST_PMU run on powering
up stage and _PRE_PMD and _POST_PMD run on powering
down stage. Please check what's going on with your system.


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