Kernel 5.18 dropped GPU voltage control for NAVI22?

[jntesteves]

I'm on Fedora Silverblue 36, and a recent update just pulled in kernel 5.18.4, and with that kernel, the voltage option on CoreCtrl disappeared. I checked the kernel boot parameters and

amdgpu.ppfeaturemask=0xffffffff

is still there. Checking at runtime with the command

printf '0x%08x\n' $(cat /sys/module/amdgpu/parameters/ppfeaturemask)

also yields the correct value.

I reboot into the previous deployment with kernel 5.17.13 and with that version I have the voltage option back working as usual.

I'm on a laptop with the RX 6800M GPU, which is NAVI22/NAVY_FLOUNDER like the RX 6700 XT. Can anyone with similar RDNA2 GPU reproduce this problem with kernel 5.18? Anyone knows if the removal is planned or likely a regression? I noticed lots of firmware got updated.

[sobrus]

I have SIENNA_CICHILD running 5.18.6 and voltage seems to be working as intended. Not using CoreCtl though, just a bash script.

echo "vo -250" > /sys/class/drm/card0/device/pp_od_clk_voltage

then checking voltage and power draw with:

cat /sys/kernel/debug/dri/0/amdgpu_pm_info

[jntesteves]

An update: 5 months later, I finally decided to investigate the code changes, and I found out that setting voltages is still working, only reporting is broken on mobile GPUs. I've sent a patch to upstream kernel fixing the problem: https://lists.freedesktop.org/archiv...er/086544.html

Though, they haven't accepted the patch yet. Without correct reporting, CoreCtrl doesn't work, and I don't want to be building a custom Kernel for long. So in the meantime, I decided to roll out my own solution for undervolting, and I liked it so much I even uninstalled CoreCtrl and this is what I use now: https://codeberg.org/jntesteves/amdgpu-tune

Problem solved.