Odissey G9 flicker at 240hz and Custom Resolution:

Odissey G9 at 240hz flicker fix

Custom Resolution:
Install CRU from https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

Extract your current monitor EDID:
cat /sys/class/drm/card1-HDMI-A-1/edid > ~/Documents/my_monitor_edid.bin

Open CRU;
In CRU load the above generated my_monitor_edid.bin (via the import)
Follow my 3 steps comment here:
https://community.lemansultimate.com/index.php?threads/triple-screen-rendering-on-ultrawide-samsung-g9.814/page-5#post-40549

From CRU export the changed edid, name it like my_edid_fixed.bin, this edit has the fixed resolution, use your new edid in the bellow Flicker FIX tutorial:
ou can as well test it with:
cat my_edid_fixed.bin >/sys/kernel/debug/dri/1/DP-1/edid_override
echo 1 >/sys/kernel/debug/dri/1/DP-1/trigger_hotplug 

Flicker FIX:

#Odissey G9 flicker at 240hz:
-> add this as grub boot argument to fix resolution on VTs:
video=DP-1:2560x1440@120

-> Systemd unit:
#localhost:~ # cat /etc/systemd/system/fixres.service 
[Unit]
Description=Fix Resolution

[Service]
Type=oneshot
ExecStart=/usr/bin/fixres

[Install]
WantedBy=multi-user.target

-> Script that systemd unit calls: (it may be 1 or 0, in my case its 0)
#localhost:~ # cat /usr/bin/fixres 

#!/bin/bash
cat /root/MYEDID >/sys/kernel/debug/dri/1/DP-1/edid_override
echo 1 >/sys/kernel/debug/dri/1/DP-1/trigger_hotplug 

#get MYEDID on the bellow link and place into /root
#https://gitlab.freedesktop.org/drm/amd/-/issues/1442#note_1017689


-> Make script executable and enable and start the systemd service:
chmod +x /usr/bin/fixres
systemctl enable fixres.service
systemctl start fixres.service