Comment 7 for bug 1912773

Fixed it! However I'm not sure why the file was created when I'm running on AMD hardware and requiring the use of the APU.

The bug is that a blacklist file was created in:

/etc/modprobe.d/blacklist-amdgpu.conf

With the following line:

blacklist amdgpu

That obviously prevented the APU drivers to load up, so the HDMI audio sink could be initialised and prevented GPU rendering.

This problem could likely affect multiple people and are unaware if they are on a single display and using speakers connected to the motherboard instead of via other means such as the 3.5mm output, optical, or even via Bluetooth. Since the system worked otherwise. The only symptom people on single displays and not using HDMI audio people would experience is when doing anything CPU or GPU intensive, since I can only presume the CPU is doing all the legwork to render the display instead of the APU.

For reference the CPU is a AMD Ryzen 5 3400g with Vega 11 APU, and no dedicated graphics card.

If anyone needs any additional information, logs, or anything let me know and I'll be happy to help out where I can. I'm just glad that I got this resolved, but I'd hate for others to experience the same issues while updates trickle down (it could also be months before anyone notices on single display and no HDMI audio setups).