If the BIOS option "iGPU multi-monitor" is enabled (so I can use the internal GPU ports, namely DVI) amdgpu.ppfeaturemask doesn't do anything anymore.
"cat /sys/module/amdgpu/parameters/ppfeaturemask" gives the mask I set (either fffd7fff or simply 0xffffffff) but the files like /sys/class/drm/card0/device/pp_od_clk_voltage don't actually get created. They do if I disable iGPU multi-monitor.
Wether I'm on kernel 5.3.6 or 5.4rc2 doesn't matter, wether I'm on Mesa 19.2 or 19.3 (git) doesn't matter as well.
Please attach your dmesg output and xorg log (if using X).
Created attachment 145780 [details]
Created attachment 145781 [details]
Thanks for taking a look :)
I am really sorry. I completely overlooked that my external GPU might simply be card1 and the internal one card0. Because that's the case. The files are all there in /sys/class/drm/card1/device/ like expected.