[Sound-open-firmware] Changing Fedora 34 default driver for BYT + CHT back to SST?

[Hans de Goede]

Hi All,

First of all this is NOT intended as a way to get more attention to recently
noticed BYT/CHT bugs. I realize it may feel that way but that is not my intention.
My goal of this email is to have a honest discussion about what will be
the best driver to use by default for BYT/CHT for Fedora 34.

With that said, there are a number of SOF related issues with audio on BYT/CHT
devices, some recent issues and one issue which is fixed, but only in 1.7 for
which no release has been made yet:

"[BUG][BYT][CHT] Output channel left/right swap on various BYT/CHT devices with various codecs"
https://github.com/thesofproject/sof/issues/3699
Status: Fixed in master, but still present in latest sof-bin release (1.6.1)

"[BUG][BYT][CHT] Linux 5.11 Cherrytrail/rt5640 emits persistent beeping sound after a short while"
https://github.com/thesofproject/sof/issues/3868
Status: Still being investigated.

"[BUG][CHT] loud crackle from speakers at boot, which does not happen with SST driver"
https://github.com/thesofproject/sof/issues/3932
Status: Still being investigated.

"[BUG][BYT] SOF hangs, logger shows "dw_dma_start(): dma 1 channel 1 not ready" error"
https://github.com/thesofproject/sof/issues/3937
Status: Still being investigated, configuring pipewire to use 16 bits samples
seems to be a workaround (but I did manage to trigger 3868 in that configuration)

The crackle is more of an annoyance then a blocker (but it is quite annoying),
but the 2 beep/hang bugs are kinda showstoppers IMHO.

As such ATM I believe that the best way forward is for me to flip the default
for Fedora 34 back to SST during the coming week (before the final freeze kicks in)
and then to try again with Fedora 35.

Regards,

Hans