snd_hda_intel/sst-acpi sound breakage on suspend/resume since 5.6-rc1

[Pierre-Louis Bossart]

On 3/18/20 11:20 AM, Dominik Brodowski wrote:
> On Wed, Mar 18, 2020 at 10:13:54AM -0500, Pierre-Louis Bossart wrote:
>>
>>
>>>>> While 5.5.x works fine, mainline as of ac309e7744be (v5.6-rc6+) causes me
>>>>> some sound-related trouble: after boot, the sound works fine -- but once I
>>>>> suspend and resume my broadwell-based XPS13, I need to switch to headphone
>>>>> and back to speaker to hear something. But what I hear isn't music but
>>>>> garbled output.
>>
>> It's my understanding that the use of the haswell driver is opt-in for Dell
>> XPS13 9343. When we run the SOF driver on this device, we have to explicitly
>> bypass an ACPI quirk that forces HDAudio to be used:
>>
>> https://github.com/thesofproject/linux/commit/944b6a2d620a556424ed4195c8428485fcb6c2bd
>>
>> Have you tried to run in plain vanilla HDAudio mode?
> 
> I had (see 18d78b64fddc), but not any more in years (and I'd like to keep
> using I2S, which has worked flawlessly in these years).

ok. I don't think Intel folks have this device available, or it's used 
for other things, but if you want to bisect on you may want to use [1] 
to solve DRM issues. I used it to make Broadwell/Samus work again with SOF.

[1] 
https://gitlab.freedesktop.org/drm/intel/uploads/ef10c6c27fdc53d114f827bb72b078aa/0001-drm-i915-psr-Force-PSR-probe-only-after-full-initial.patch.txt

An alternate path would be to switch to SOF. It's still viewed as a 
developer option but Broadwell/Samus work reliably for me and we have a 
Broadwell-rt286 platform used for CI.