https://bugs.freedesktop.org/show_bug.cgi?id=106428

Bug ID: 106428 Summary: reported VDDGFX GPU voltage jumps above set limits in pp_od_clk_voltage when UVD is used for VAAPI/VDPAU Product: DRI Version: unspecified Hardware: x86-64 (AMD64) OS: Linux (All) Status: NEW Severity: normal Priority: medium Component: DRM/AMDgpu Assignee: dri-devel@lists.freedesktop.org Reporter: tempel.julian@gmail.com

I adjusted my pstates in "/sys/class/drm/card0/device/pp_od_clk_voltage" that the GPU voltage should never be above 900 mV:

(...) 5: 1126Mhz 880 mV 6: 1180Mhz 890 mV 7: 1209Mhz 900 mV

And in normal 3D applications "watch -n 0.5 cat /sys/kernel/debug/dri/0/amdgpu_pm_info" accordingly never reports more than 900 mV for VDDGFX.

But when I play a video in mpv with VAAPI/VDPAU, reported VDDGFX often jumps to 1100 mV, which clearly is undesired behavior. It sticks again to normal 900 mV as soon as I disable hardware decoding.

Now the question is, if the reported voltage is correct (then adjusting pp_od_clk_voltage has a bug) or if the real voltage is just reported wrong (than information in amdgpu_pm_info would be wrong).

Happens with both 4.17rc2 and drm-next-4.18-wip. GPU is RX 560.