"pp_od_clk_voltage" unavailable on Hawaii GPU (R9 390)

Submitted by Jonas del Campo

Assigned to Default DRI bug account

Link to original bug (#111584)

Description

I have recently tried to overclock/undervolt my GPU (R9 390) within Linux thanks to the "amdgpu.ppfeaturemask=0xffffffff" boot parameter, but unfortunately the file "pp_od_clk_voltage" is not available after a reboot.

Files "pp_dpm_mclk" and "pp_dpm_sclk" however show correct states and MHz, except that they don't show voltage information. Changing "power_dpm_force_performance_level" to manual allows me to make changes to these files, I can force a state to be used and overclock it, but voltages aren't showed and can't be modified.

I have read that Southern Island GPUs were not expected to get this feature working, and I know Vega is compatible, but I can't find anywhere if Hawaii (CIK) hardware should be able to expose this feature. I might be missing something.

Is there any way to undervolt my GPU under Linux at the moment?

Specs:
OS: Arch Linux
Kernel: 5.2.11.arch1-1
Mesa: 19.1.6-1
Xorg: 1.20.5-2
Boot parameters: radeon.cik_support=0 amdgpu.cik_support=1 amdgpu.dpm=1 amdgpu.dc=1 amdgpu.ppfeaturemask=0xffffffff
GPU: [AMD/ATI] Hawaii PRO [Radeon R9 290/390] (rev 80)

Feel free to ask for more details and output if needed.

Thank you for your time.