External Monitors Blank in Debian Distros 20.04 and on

Hey so I’m using a six week old HP Omen 15 with the Ryzen 4800H and the GTX GeForce 1660 Ti. I’m dual booting with Windows 10 for research purposes and need both OS’s. I have had external monitors working with Ubuntu 20.04 in the past and they always work with Windows 10, but for the last week or so I haven’t been able to get any linux distros (mostly ubuntu/debian based but I also tried Manjaro as well). I would appreciate some help figuring out what is wrong so that I can get back to work instead of fixing my computer. Here’s my nvidia bug report on the nvidia profile: nvidia-bug-report.log.gz (430.4 KB)

Also note that I am running kernel version 5.8.14 and third party nvidia driver 455 on ubuntu 20.04.1 LTS currently and that was how the log file was produced.

Oh and I’m running the 455 driver from the ppa:graphics-drivers/ppa

It looks like you’re using a so-called “Reverse PRIME” display offload configuration where amdgpu is rendering the desktop and your system is trying to use display offload to display on devices connected to the NVIDIA dGPU. Unfortunately, this configuration is known not to work due to a compatibility problem between the way the NVIDIA driver tries to import the shared memory for display and the way the amdgpu driver allocates it when transparent hugepage support is enabled in the kernel. There is some discussion about it here: https://lore.kernel.org/dri-devel/20200930221821.13719-1-agoins@nvidia.com/T/

We’re looking into what is necessary to make this combination work. Unfortunately, in the meantime it’s not sufficient to just disable transparent hugepages by writing to /sys/kernel/mm/transparent_hugepage/enabled – the only current workaround is to recompile the kernel with CONFIG_TRANSPARENT_HUGEPAGE disabled.

For future reference, the internal bug number tracking this is 2759189.

Thank you so much for the information! Hopefully I’ll have something working soon!