[alsa-devel] Surface 3 audio broken between 4.11 and 4.13 (rt5645)

[Bastien Nocera]

Hey Pierre-Louis,

On Fri, 2017-10-13 at 18:49 -0500, Pierre-Louis Bossart wrote:
> 
> On 10/13/2017 01:40 PM, Bastien Nocera wrote:
> > Hey,
> > 
> > As I was trying to test PulseAudio HDMI LPE audio support fixes, I
> > realised that the internal sound card of my Surface 3 wasn't
> > working
> > anymore, using the same user-space configuration.
> > 
> > Looks like detection of the device regressed between 2 versions.
> > Does
> > this look familiar to anyone, or should I start bisecting? (which
> > will
> > take me absolutely ages, as the CPU is anemic on that machine)
> 
> Yes this looks familiar unfortunately. Surface has a BIOS quirk
> iirc, 
> and there are reports of broken audio on other platforms that have a 
> similar quirk, see
> https://bugzilla.kernel.org/show_bug.cgi?id=96691 where the patch 
> 7827d66946ad3af734ed46d1d68c23fa6974595c is flagged as being the
> issue.
> 
> I tried providing a patch for what I think is the problem, but the 
> reports from users were inconsistent and I don't have access to the 
> hardware.
> 
> If you could try both the revert and the suggested fix (separately)
> it'd 
> help a great deal

I compiled 2 test kernels with each one of those patches, tested them
both and added the results to the bug.

Did you want to continue the discussion here, or should I add that
information to the (rather long-winded) bug?

Cheers