Does anyone know the proper settings to use when wanting to enable a resolution not exposed by EDID in a DVI display? I've extensively searched for the right xorg.conf settings but it seems the driver ignores any custom display modeset as invalid even when bypassing EDID checks.
I know for a fact that the resolution I'm trying to achieve, while not in the display's EDID, is supported by the display (used in Windows 10).
Get your monitor's EDID and save it to a file. You can do that from Linux, with read-edid.
Then go to Windows and get the parameters for the working mode. I no longer remember the details (I had to do this only once, and it was a few years ago), but there are Windows utilities for that, and they're pretty easy to find.
Then edit the EDID file to include the new mode. I think I wrote a Perl script at the time, but you might be able to find other (Windows) utilities to do that for you.
If you end up having to do the plumbing yourself, the format is described at Wikipedia, and there are a few posts here that might help you, such as this, this, and this. In particular there's an edid-generator program that looks like an useful start.
Beware that the order of entries in the EDID file is important. If I recall correctly you want your preferred mode first.
When you have the cooked EDID file copy it to Linux, and point xorg to it. Back when I did that I had to add an option like this to the Device section in my xorg.conf:
Option "CustomEDID" "DFP-1:/etc/X11/EDID.bin"
These days Xorg ignores xorg.conf, so you'll have to hunt around to re-enable it. The CustomEDID is documented in nVidia driver's docs; you'll need to adjust that too, to fit your particular setup.
