KDE 5.56 SDDM Login screen resolution on HiDPI FHD screen

Question

OP on reddit

Hi,

I have a problem with Kubuntu 19.04 in my 13" FHD (1920x1080) laptop screen. The login screen is too small as was the whole Plasma KDE.

I was able to re-scale the screen to 1.5 (150%) and now Plasma KDE looks great but the login screen still remains small (FHD scaled) though when I come back from Suspend mode the login screen do re-scales to 150%.

There is no file called sddm.conf under /etc/, as written in the project's github page, in my OS sddm.conf located under /etc/init.

I have added the lines

[X11]
ServerArguments=-nolisten tcp -dpi 144

At beginning of /etc/init/sddm.conf where 144 represents my base resolution in DPI as written in the X-Server information * 1.5 but still it doesn't fix the login screen resolution scale.

Any suggestions will be gladly welcomed.

TNX

Answer 1

In my Kubuntu 19.10, /etc/init/sddm.conf appears to contain script code instead of config variables. /etc/sddm.conf did exist, perhaps because this is based on Ubuntu 18.04.3 LTS that came with the XPS 13:

$ cat /etc/sddm.conf 
[Autologin]
Relogin=false
Session=
User=

[General]
HaltCommand=
RebootCommand=

[Theme]
Current=ubuntu-theme
CursorTheme=breeze_cursors

[Users]
MaximumUid=60000
MinimumUid=1000

[X11]
ServerArguments=-nolisten tcp -dpi 144

I added the [X11] section myself, rebooted, and now the initial login screen is more easily readable, as well as the session apps and lock screen. Even at Displays scale 1 i had to revert Fonts from 13 to 11 and lower. I'm running this QFHD at FHD to save battery and config stress:

PS: You can calculate the proper PPI; QFHD in 13.3" is 331 and FHD on the same is 166.