Scaling issue with nvidia gpu and gdm3?

[cjchristopher]

• xrandr-extend version: 0.3.0
• Python version: 3.10.6
• Operating System: Ubuntu 22.04.1 gdm3

Description

External HDMI has 4x zoomed (i.e. I can only see the top left corner of a theoretical secondary 3840x2160)

What I Did

pip install xrandr-extend
python3 -m xrandr_extend.cfg

Edited ~/.config/xrandr-extend.cfg as follows:
set primary = 3840, 2160 in [resolutions]
added: [nvidia-g0] as a provider after being instructed by xrandr-extend hdmi with primary = eDP-1 and hdmi = HDMI-1-0

> xrandr-extend hdmi
xrandr --auto
xrandr --listmonitors
xrandr --output eDP-1 --auto --output HDMI-1-0 --auto --scale 2.0x2.0 --right-of eDP-1
Monitors: 2
 0: +*eDP-1 3840/344x2160/194+0+0  eDP-1
 1: +HDMI-1-0 3840/531x2160/299+3840+0  HDMI-1-0

Running with -x 1 hdmi gives me a properly fixed window 1920x1080, but UI elements are all scaled to twice the size (i.e. enormous). A note that UI elements seem to be 2x scaled on the primary 4k laptop display, which is what I want, as without 2x UI scaling there, everything is impossibly small.
Essentially I want: primary to be at 4k with 2x UI scaling, secondary to be at 1080p with 1x UI scaling.

[ashwinvis]

Have you tested fractional scaling? For example 1.5?

[ashwinvis]

You can also test the --pan option.

[cjchristopher]

No dice with either/both. Fractional scaling still has the same problems (primary looks fine, secondary just upper right corner), and --pan fails outright with:

BadMatch (invalid parameter attributes)
   Major opcode of failed request: 140 (RANDR)
   Minor opcode of failed request: 29 (RRSetPanning)
   Serial number of failed request: 49
   Current serial number in output stream: 49

[ashwinvis]

Can you share a screenshot of before and after @cjchristopher ?

[cjchristopher]

I get different behaviour depending on the state before (resolutions and scaling), but in any case, no matter what state I have things in before, the after state is still not what I intend.
Which before state (and subsequent after) would you like me to provide screenshots of?

[ashwinvis]

Screenshots / photos of both the monitors before and after executing xrandr-extend.