This is reproductible on kernel 4.9-rc7 even with the branch drm-fixes-4.9 from agd5f repository merged https://cgit.freedesktop.org/~agd5f/linux/log/?h=drm-fixes-4.9 The branch was pointing on bcfdd5d5105087e6f33dfeb08a1ca6b2c0287b61 when I merged it. I can use amdgpu with dpm=0 but performance is bad (not surprising for an experimental support on southern island). I would like to bisect but the dpm never worked on amdgpu SI as far as I know.