Bugzilla – Bug 1221523
kcm_sddm package unable to set UI scaling in SDDM after upgrading to KDE Plasma 6
Last modified: 2024-03-30 08:50:10 UTC
After upgrading to KDE Plasma 6, SDDM does not scale its UI to 200% on my laptop's HiDPI screen (2880x1800, 90Hz, 14 inches). I'm using the Wayland session of KDE Plasma. UI Scaling in the actual desktop seems to work without any issues. Now that sddm_kcm6 is available, I tried pressing "apply plasma settings", however, unlike in KDE Plasma 5, this does not fix the issue anymore. I have tried changing my SDDM theme and it correctly applied, so it's the UI scaling in particular that does not seem to be working. Here is my SDDM configuration. I have not made any manual changes to the configuration files. This is what KDE Plasma 6 sets using the sddm_kcm6 package: /usr/lib/sddm/sddm.conf.d/00-general.conf: [XDisplay] ServerPath=/usr/bin/X SessionCommand=/usr/etc/X11/xdm/Xsession DisplayCommand=/usr/etc/X11/xdm/Xsetup # No effect in 0.20.0, might change in the future again MinimumVT=7 # boo#1089932 EnableHiDPI=true [Users] # boo#979775 ReuseSession=true /usr/lib/sddm/sddm.conf.d/10-plasma.conf # No effect in 0.20.0, might change in the future again MinimumVT=7 # boo#1089932 EnableHiDPI=true [Users] # boo#979775 ReuseSession=true yorimirus@localhost:/usr/lib/sddm/sddm.conf.d> cat 10-plasma.conf [General] GreeterEnvironment=QT_WAYLAND_SHELL_INTEGRATION=layer-shell [Theme] Current=breeze CursorTheme=breeze_cursors [Wayland] CompositorCommand=kwin_wayland --no-global-shortcuts --no-lockscreen --locale1 /usr/lib/sddm/sddm.conf.d/10-theme.conf [Theme] Current=breeze-openSUSE CursorTheme=breeze_cursors /usr/lib/sddm/sddm.conf.d/11-kwin_wayland.conf [General] GreeterEnvironment=QT_WAYLAND_SHELL_INTEGRATION=layer-shell [Wayland] # --locale1 was introduced in kwin 5.27 CompositorCommand=kwin_wayland --no-global-shortcuts --no-lockscreen --locale1 /usr/lib/sddm/sddm.conf.d/20-breeze-openSUSE.conf [Theme] Current=breeze-openSUSE /etc/sddm.conf.d/kde_settings.conf [Autologin] Relogin=false Session=default.desktop User= [General] HaltCommand= RebootCommand= [Theme] Current=breeze CursorSize= CursorTheme=breeze_cursors Font=Noto Sans,10,-1,0,400,0,0,0,0,0,0,0,0,0,0,1 [Users] MaximumUid=60000 MinimumUid=1000 [X11] ServerArguments=-dpi 192 It seems like some DPI parameter is being set but SDDM ignores it.
I have managed to work around this issue by creating a file called hidpi.conf in the /etc/sddm.conf.d directory with this content: [General] GreeterEnvironment=QT_SCREEN_SCALE_FACTORS=2,QT_FONT_DPI=192 [Wayland] EnableHiDPI=true [X11] EnableHiDPI=true ServerArguments=-nolisten tcp -dpi 192 It seems like the problem isn't with SDDM but with the sddm-kcm6 package. After creating this file SDDM is properly scaled to 200%.
Fixed in 6.0.3: https://bugs.kde.org/show_bug.cgi?id=467039 Closing report.