vc4.ko brings unusable&unstable ALSA sinks

[Ryutaroh Matsumoto]

Hi Diederik,

> How did you configure your system to use that?

Is https://lists.debian.org/debian-arm/2021/03/msg00082.html
enough as an answer to your question?

> Does that also support multi-channel audio?

"pactl list sinks" says "stereo". But, as my display does not equip two speakers,
paplay /usr/share/sounds/alsa/Front_Left.wav and Front_Right.wav
gives no difference... I don't have a clear answer.

>> bcm2835_audio bcm2835_audio: vchi message timeout
> I think I've seen that msg too.
> I don't know what my config was with that; tried so many.

I wonder if the pulseaudio causes the messages by touching vc4hdmi ALSA sinks.
If it is the case, commenting out "load-module module-udev-detect" and
"load-module module-detect" from /etc/pulse/default.pa should fixes the symptom.
That messages completely went away from my Debian on RPi4B.

Best regards, Ryutaroh