xrandr --scale 0.5 confines display to native solution on secondary sceen, but mouse moves on the upscaled screen

[Johannes Kalliauer]

`--scale 0.5 --filter nearest` works on the internal screen, however not on the external screen (via USB-C with Display-Port)

`xrandr --output eDP-1 --primary --mode 1920x1080 --pos 0x0 --scale 0.5 --filter nearest --dpi 141 --output DP-1-3 --mode 3840x2160 --scale .5 --pos 960x0 --filter nearest`

results in a display of the solution 1920x1080 (upper left quater), however the mouse uses the whole 3840x2160-space, leading to an offset between mouse and display.

However this does not occur on the internal screen.

xrandr:
xrandr program version 1.5.1
Server reports RandR version 1.6

host:
 Static hostname: lws84.imws.tuwien.ac.at
       Icon name: computer-laptop
         Chassis: laptop
Operating System: Fedora 34 (Workstation Edition)
     CPE OS Name: cpe:/o:fedoraproject:fedora:34
          Kernel: Linux 5.13.4-200.fc34.x86_64
    Architecture: x86-64
 Hardware Vendor: Lenovo
  Hardware Model: ThinkPad P15 Gen 1

Screen:
https://www.lg.com/de/monitore/lg-27UK670-B

[Daniel van Vugt (vanvugt)]

Sorry but Fedora is not supported here. You should use https://bugzilla.redhat.com/ instead.

[Bartłomiej Kamiński (fizyk20)]

I have the same issue on Arch Linux currently, were there any further developments with this bug anywhere?

[Daniel van Vugt (vanvugt)]

Generally we don't support custom xrandr --scale settings in Ubuntu because it conflicts with the fractional scaling patch, so bugs are expected if you modify the internals like that. Still, if you would like to discuss any such bug then please report it by running:

  ubuntu-bug mutter