Linux 6.7.x on AMD GPU RX570 requires the kernel parameter amdgpu.dc=0

Symptoms: Running Fedora 38 and 39 with kernels 6.7.7 on AMD Ryzen 5 with AMD GPU RX570 (Sapphire Radeon PULSE ITX RX 570 4GD5, 4GB GDDR5) sometimes results in a blank screen (no video signal, monitor going to sleep mode) after the boot. The display manager (sddm, wayland) does not start (or is not visible, there is no video) and it is not possible to login or switch to a virtual console.

It was possible to login to the computer through the ssh over the network though. Inspection of dmesg found the following suspicious message:

[ 7.708052] amdgpu 0000:09:00.0: [drm] Cannot find any crtc or sizes

Googling that message led to the bbs.archlinux forum with the advise from April 2020 to add the kernel boot command line parameter: amdgpu.dc=0

This solved the blank screen issue. I added this parameter in /etc/default/grub to the parameter GRUB_CMDLINE_LINUX, and regenerated the main configuration file with grub2-mkconfig.

Other forums indicate that the root cause of the problem was solved in the amdgpu driver later in 2020, so it is unclear to me why this is still required in 2024.

There is still another problem though: switching from wayland screen to the textual virtual console and back results in a “randomized” wayland screen, which does not work. Ahhh…. is it time to buy a new GPU already?


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