Comment # 3 on bug 1180563 from Felix Niederwanger

Thanks for looking into this! The suggested boot option solved the issue for
me.

I've added  snd_hda_codec_hdmi.enable_silent_stream=0  in the GRUB entry and
the system is functional again. Tried a reboot without this entry and ended up
with a frozen system again. It looks indeed like a regression in the HDMI audio
system.


The line

> Jan 05 09:55:33 racetrack-7290 kernel: i915 0000:00:02.0: [drm] Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.

is present also in the 5.9 logs.