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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Mon, 29 Oct 2018 19:52:48 +0200
Message-ID: <CAHp75VfnN5tF1Z9+CDDhKFNG5QfCRcGOZeAkpf-5BfCEx16gvg@mail.gmail.com>
Subject: Re: Regression found (Stop-marking-clocks-as-CLK_IS_CRITICAL)
To:     Stephen Boyd <sboyd@kernel.org>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc:     duffydack73@gmail.com, Hans de Goede <hdegoede@redhat.com>,
        Michael Turquette <mturquette@baylibre.com>,
        linux-clk <linux-clk@vger.kernel.org>,
        Stable <stable@vger.kernel.org>,
        Johannes Stezenbach <js@sig21.net>,
        Carlo Caione <carlo@endlessm.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Cc: Pierre as well.

On Mon, Oct 29, 2018 at 7:48 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Dean Wallace (2018-10-25 16:25:17)
> > I have found a regression in 4.18.15 that means I lose sound on my old
> > Toshiba Chromebook 2 (Swanky).  My system details are:-
> >
> > Toshiba Chromebook (Swanky)
> > MrChromebox UEFI coreboot
> > Arch Linux running latest alsa/pulseaudio
> >
> > Upgraded kernel from 4.18.14 to 4.18.15 and lost all sound output.  By
> > output I mean, the card is still detected, the module loaded, all apps
> > showing sound is being playing, but no actual audible sound comes
> > through.  Upgraded to 4.18.16 same issue.
> >
> > Dug around and found Upstream commit 648e921888ad96ea3dc922739e96716ad3225d7f
> > clk: x86: Stop marking clocks as CLK_IS_CRITICAL
> > "This commit removes the CLK_IS_CRITICAL marking, fixing Cherry Trail
> > devices not being able to reach S0i3 greatly decreasing their battery
> > drain when suspended."
> >
> > I reverted it and compiled 4.18.16 and have sound back again.  Could
> > this be looked into, with possibility of fix.
> >
>
> Thanks for the bug report. I'm adding some people involved in the commit
> you mention is causing audio regressions. The best plan is to probably
> revert the commit from the 4.18 linux stable tree. Or there may be
> another patch missing that would be useful to make this backported patch
> work. Hopefully Hans or Andy knows.

Hans has been investigating S0ix issues on Baytrail and Cherrytrail machines.
I have a feeling that the problem can be fixed by properly handling
clock in ASoC driver(s). Perhaps Hans and Pierre can figure this out
better than me.

-- 
With Best Regards,
Andy Shevchenko