https://bugs.freedesktop.org/show_bug.cgi?id=101988
--- Comment #10 from Michel Dänzer michel@daenzer.net --- (In reply to newincpp from comment #5)
[ 107.804672] amdgpu 0000:01:00.0: SI support provided by radeon. [ 107.804674] amdgpu 0000:01:00.0: Use radeon.si_support=0 amdgpu.si_support=1 to override.
Follow this advice and set radeon.si_support=0 amdgpu.si_support=1 to use the amdgpu driver. (In exchange, you no longer need to blacklist the radeon driver)