5.14 regression, Intel SST (BYT) audio no longer works

[Pierre-Louis Bossart]

>> I just noticed and I won't have time to dig any deeper for approx. the
>> coming 10 days. Still I wanted to report this in case anyone has any
>> ideas. Or maybe you can reproduce and look for a fix ?
>>
>> After building + installing 5.14-rc1 on a HP Elitepad 1000 G2
>> (Bay Trail) with a RT5642 codec, I noticed that sound over the
>> speakers and over the docks line-out jack no longer works.
>>
>> Downgrading to 5.13 (without any other changes) fixes this, so this
>> seems to be a regression with 5.14.
>>
>> I've no been able to make time to test this on other BYT/CHT hardware,
>> but I suspect that other models will be affected too.
> 
> Thanks Hans for the report, will look into this. 
> I can't think of anything that might explain this regression.
> I need to update the series to remove device properties so if the baseline is broken I'll see it as well...

I don't see any issues seen on a headless CHT Zotac device with RT5640, both with v5.14-rc1 or broonie/for-next.
Maybe something else happening with e.g. ACPI or GPIOs?