Odissey G9 flicker at 240hz and Custom Resolution:

Odissey G9 at 240hz flicker fix

Get the correct monitor: (in my case card1-DP-2)

simrig:/home/slemke # cat /sys/class/drm/card1-DP-1/modes |head -n 1
2560x1440
simrig:/home/slemke # cat /sys/class/drm/card1-DP-2/modes |head -n 1
5120x1440
simrig:/home/slemke # 

Download g9.bin from:
https://github.com/gouineblade/odysseyg9-linux-240hz-vrr-hdr-noflicker


--> Test: (will not make the edid persistent)

Get the monitor using the above commnd example.

cat g9.bin >/sys/kernel/debug/dri/1/DP-2/edid_override
echo 1 >/sys/kernel/debug/dri/1/DP-2/trigger_hotplug

<-- end Test


If all good you can make it persistent:

simrig:/home/slemke # cp g9.bin /usr/lib/firmware/edid/g9.bin
simrig:/home/slemke # 

Create:
simrig:/home/slemke # cat /etc/dracut.conf.d/99-custom-edid.conf
install_items+=" /usr/lib/firmware/edid/g9.bin "
simrig:/home/slemke # 

Add the DRM line to the default kernel:
simrig:/home/slemke # grep GRUB_CMDLINE_LINUX_DEFAULT /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="mitigations=off amdgpu.ppfeaturemask=0xffffffff drm.edid_firmware=DP-2:edid/g9.bin"
simrig:/home/slemke #

Regenerate initrd:
dracut --force

Confirm it's added to  initrd:
lsinitrd | grep g9.bin

reboot to test.