Comment # 13 on bug 1177169 from Nicolas Patricio Saenz Julienne

Hi Zlatko,
with v5.10 the new display controller is indeed available. It should also take
care of HDMI sound. I've been looking into enabling it by default for all
Tumbleweed users, but some use-cases are broken at the moment. Specifically DSI
displays. The RPi foundation guys are working on it and I don't think we can
enable it by default until that's fixed.

As for HDMI, some other fixes are needed[1]. They'll eventually make their way
into the stable branches.

Once they are available and as long as you're using HDMI, you'll be able to
test it by editing the config.txt file in the EFI partition (on a live system
you'll find it in /boot/efi/config.txt).

replacing this:

  dtoverlay=disable-vc4

with,

  dtoverlay=vc4-kms-v3d,cma-default

I'll update this issue once TW's kernel is ready. pulseaudio should then work
out of the box (as long as it's installed in the system). 

[1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2443433.html