https://bugzilla.kernel.org/show_bug.cgi?id=207137

Bug ID: 207137 Summary: AMDGPU incorrectly reports vddgfx voltage for R9 390 Product: Drivers Version: 2.5 Kernel Version: 5.6 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: low Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: sandy.8925@gmail.com Regression: No

I'm using an R9 390 GPU.

vddgfx voltage is always reported as 1 Volt, regardless of load.

I debugged and found that in smu7_hwmgr.c , in funcion smu7_read_sensor(), the voltage is read from PLANE2_VID when a certain condition is true. This always results in a final value of 1 Volt.

When I changed the code to read only from PLANE1_VID, the correct voltage seems to be reported, and it changes under load, from ~900 mv to 1.3 V.

Please fix.