Comment # 3 on bug 1207129 from Takashi Iwai

Now I'm building a test KMP with a test patch for this device (in USB mode).
It's built in OBS home:tiwai:bsc1207129 repo, for TW and Leap kernels.

Alexander, could give it a try later once after the build finishes?
Just grab usb-audio-kmp-default.rpm from the repo, install it, reboot and
retest.

On my machine, the volume up/down works a bit better, but not perfectly (e.g.
the volume bar changes but no actual volume changes unless I manually "set" the
volume in pavucontrol).

As Leap 15.2 was already out of maintenance, I can't provide a fix,
unfortunately.