Gave this issue another round of thought. After some good old googling, turns out this issue is probably due to Amdgpu’s dpm setting, the dynamic power management: https://github.com/openbsd/src/blob/master/sys/dev/pci/drm/amd/amdgpu/amdgpu_drv.c#L305
I tried rebuilding a GENERIC kernel (from -current cvs tree) by hardcoding amdgpu_dpm = 0. It worked fine even with the amdgpu firmware. On Linux one can set this value with a kernel param, but on OpenBSD this isn’t obviously possible. Is there a way one could set this flag to a different value without recompiling the kernel? Thank you all.
