[pulseaudio-discuss] why isn't PA using hardware volume controls?

[Ernest Adrogué]

> Is this how it's supposed to work or am I doing something wrong here?

I've found a clue:

W: [pulseaudio] alsa-mixer.c: Volume element Master has 8 channels. That's
too much! I can't handle that!

and

I: [pulseaudio] alsa-sink.c: Driver does not support hardware volume
control, falling back to software volume control.

So I guess this explains it.