I found a complete solution for my over/underscan problems in GNOME. Apparently there is a clone of ~/.config/monitors.xml
logical
0
0
1.25
yes
eDP-1
AUO
0x208d
0x00000000
1920
1080
60,049
yes
for the GDM ( /var/lib/gdm/.config/monitors.xml ):
logical
0
0
1.25
yes
eDP-1
AUO
0x208d
0x00000000
1920
1080
60,049
yes
Note that this is not available on Ubuntu. I think that if we find this file in Fedo 41 it is because RedHat is pushing to go Wayland-only and abandon Xorg which is too heavy to manage, so the GNOME devs had to port GDM to Wayland. I don’t know if you noticed, but Pantheon DE and Cinnamon DE/LinuxMint have released experimental Wayland versions. By the way, XFCE DE is also getting involved:
- Fedora: Changes/WaylandOnlyGNOMEWorkstationMedia - Fedora Project Wiki
- Cinnamon: I Tried The New Cinnamon 6.4 Release With EndeavourOS: Here's How It Looks
- XFCE: Xfce 4.20 Releases With Experimental Wayland Support and More Upgrades
Two groups are currently yelling about this: NVIDIA card owners and graphic designers…
So, I managed to enable underscan in GDM.
If you are a noob like me and don’t want to get your hands dirty, this flatpak works well. It’s the one that gave me the clue by asking me to create the ~/.config/monitors.xml by changing screen settings via the settings. So here it is:
https://gdm-settings.github.io/
There should be an official GNOME customizer application, which would gather everything (gnome settings customization section, gnome-tweaks, gdm-settings, gnome-extensions…) and I suggest that all the interface customization options scattered in gnome settings be gathered there.