I have a desktop with an AMD Ryzen 7 3700X processor and a Radeon RX 5500 GPU. It worked fine in Fedora 33. I installed Fedora 34 over the NVMe disk (didn’t do an upgrade) and had to use the simple graphics installer so ended up with nomodeset on the kernel command line. Booting that way gives me a screen 1024x768 which is much less than the monitor size. Booting without nomodeset gives a black screen. vdpauinfo says “Failed to open VDPAU backend libvdpau_nvidia.so: … no such file”. Well, no, it’s a Radeon. vainfo fails with “driver_name = (null)”. lspci shows “VGA compatible controller: Advanced Micro… [Radeon RX 5500…” as expected so the GPU is talking to the bus. radeontool regs shows a long list of registers. Xorg.0.log shows errors:
open /dev/dri/card0: no such card or directory (indeed, there is no /dev/dri)
Unable to find a valid framebuffer device
Screen0 deleted because of no matching config section
I added selinux=0 to the kernel command line to eliminate that as a possible cause. So the hardware is clearly there. There is no other GPU and the MB does not have any integrated graphics. I understand that nomodeset will force simple graphics, which is what happens, but I’m in the dark (literally!) with the black screen I get without nomodeset. Any ideas?