I'll say in all honesty I've had other issues with gdm and I just don't use it anymore on Fedora (strict text boot, manually start Xorg). Are you Xorg or Wayland?
I just tested Fedora 35 workstation today.
- ast (integrated HDMI): works successfully (x11)
I powered down, placed the VGA disable jumper and tried the GPU.
- amdgpu (polaris family card): works successfully (wayland, did not test x11)
I find it very convenient that Fedora includes the amdgpu firmware OOB. After testing this I can infer that the issue is
not the GPU, video cable or cable type, board/firmware or conflict with other parts/peripherals. In fact, Debian has been a pretty poor showing on PPC lately.
- Since at least Buster, Debian fails to update initramfs automatically upon installation of firmware-amd-graphics.
- Since Bullseye (and retroactively?), Debian fails to enable the ast kernel module. Users wishing to install Debian must interact with the whiptail installer through serial to install and enable this module.
- Now, it seems, there is an issue somewhere in the display stack affecting Debian on PPC. x11 environments yield rendering issues that make the system unusable, while wayland (GNOME) does not even make it to the greeter.
The
OS specific wiki page basically exists because of me.
Sorry, RCS support. Can I send you some pizza?
