GRUB_CMDLINE_LINUX_DEFAULT="radeon.cik_support=0 amdgpu.cik_support=1 radeon.si_support=0 amdgpu.si_support=1 amdgpu.ppfeaturemask=0xffffffff radeon.dpm=0 amdgpu.dpm=1"

lspci -nnk | grep -i vga -A3 | grep 'in use'

Kernel driver in use: amdgpu

ls -l /sys/class/drm/card0/device

/sys/class/drm/card0/device -> ../../../0000:00:02.0

realpath /sys/class/drm/card0/device

readlink -f /sys/class/drm/card0/device

/sys/devices/pci0000:00/0000:00:02.0

sudo ls /sys/devices/pci0000:00/0000:00:02.0/ | grep pp_od_clk_voltage

/sys/devices/pci0000:00/0000:00:02.0/pp_od_clk_voltage

sudo nano /sys/devices/pci0000:00/0000:00:02.0/pp_od_clk_voltage