After updating to Linux 5.8, mclk and sclk are always reported as 0MHz on my AMD R9 390. this is consistent after a couple of 5.8 kernel updates with both linux-zen and generic linux. it was fine on the last 5.7 release, and going back to 5.4 LTS clocks are reported correctly as of now. issue is present with both AMDGPU and Radeon drivers
Please attach your dmesg output and Xorg log (if using X).
Created attachment 292149 [details] full dmesg for 5.8 Comparing with the 5.4 output, one difference I noticed is "[ 3.795074] amdgpu 0000:29:00.0: amdgpu: Trusted Memory Zone (TMZ) feature not supported"
Created attachment 292151 [details] Xorg log for 5.8
I just retested, clocks actually are reported correctly with the Radeon driver. this issue is specific to the AMDGPU driver AMDGPU was loading regardless of kernel cmdline before: "radeon 0000:29:00.0: CIK support disabled by module param"
Fixed with this patch: https://cgit.freedesktop.org/~agd5f/linux/commit/?h=drm-next&id=177e38a48168f9e70faaec34df053d2f8134ede6
Awesome, confirmed fixed with kernel 5.8.8