On maandag 8 februari 2021 13:22:56 CET Stefan Wahren wrote:
> > TL;DR: I have a RPi 3B+ running pure Debian Bullseye arm64 (~from
> > raspi.debian.net), named rpi-mpd, connected via HDMI cable to my AV
> > Receiver.
> can you please confirm that the bcm2835-audio driver causing the issues?

How can I confirm that?

> > Playing music worked fine with kernel 5.9, but with 5.10.2-1 the music
> > (quality) became not good to quite horribly, because of (static) noise and
> > distortion.
> > With kernel version 5.10.9 (linux-image-5.10.0-2-arm64) it all seemed
> > fixed, but returned with 5.10.12 (linux-image-5.10.0-3-arm64) and is also
> > present with 5.10.13.
> 
> I cannot explain why 5.10.9 works for you, but we had multiple
> regressions in 5.10. Currently i cannot see any of the fixes by Phil
> Elwell in linux-stable. Maybe they won't apply and needs to be backport
> manually.

FTR: All the kernel versions I mentioned are the Debian kernel versions (and 
thus also Debian's config).

> Just for reference here are the revelant patches:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/d
> rivers/staging/vc04_services?h=next-20210205&id=96ae327678eceabf455b11a88ba1
> 4ad540d4b046
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/d
> rivers/staging/vc04_services?h=next-20210205&id=88753cc19f087abe0d39644b844e
> 67a59cfb5a3d
> 
> Could you please try?

I'll try. But it may take a while as I don't know how to (properly) do that.
And I'm guessing that building on a RPi3B+ isn't exactly fast. But I assume 
I'm able to 'overcome' all that.