I’m on Fedora KDE and I’ve been trying to disable the SDDM login screen on my second monitor. I’m doing this not only because I would prefer to have the login only show on single screen, but also because SDDM seems to have assigned my secondary monitor as my primary display (I am unable to interact with my primary monitor unless I first click on it with my mouse.)
I’ve tried a solution I found on Reddit, using the SDDM scripts to disable the monitor on start up (xrandr --output HDMI-A-1 --off). I tried this with the Xsetup files in both /etc/sddm and /usr/share/sddm, but neither script seemed to disable the display as intended. I also added “DisplayCommand=/^file location^” to the sddm.conf file and tried both scripts again, but still found no success.
I assume the issue here is that I need to modify the Wayland files instead, unfortunately I’m struggling to find any definitive information on how to do so. Any advice?
Based on what I’ve gathered, it doesn’t look like it’s possible to fix this issue without modifying SDDM itself, or changing KDE’s login manager entirely. SDDM doesn’t appear to adhere to any user preferences until the user’s initial login, so nothing can be altered on default boot settings.
I’m not an expert with these programs by any means though, so there may have been something I missed. In the end, I ended up just growing accustomed to the issue, so I stopped searching for a solution. Hopefully you have more luck!
Check if SDDM also knows your secondary monitor as “HDMI-A-1”.
After you have logged in, xrandr may tell you that the name of your secondary monitor is “HDMI-A-1”, but that can be misleading.
In my case for some reason its name changes after I logged in, thats when it gets the “HDMI-A-1” name. But when I checked SDDM logs in the system journal (sudo journalctl --boot | grep sddm), I have seen that SDDM knows that display as “HDMI-1”.
After fixing the display name in /usr/share/sddm/scripts/Xsetup, it was working as expected.
Note though that (at least for me) it does not seem to help with the primary display selection, and neither really does xrandr --output your_display_name --primary, so the password prompt may still be active on the secondary display by default.
For that as I have read, you could disable the secondary display (logging in should bring it back), or make it a clone of the primary one. The latter may be more future proof, for when you upgrade your display years later.
Hi @cup-of-joe & co.,
I have been able to resolve my issue by logging into KDE/wayland, setting the screens the way I want to have them at boot (by going into Plasma Settings → Display Configuration), then going into the plasma settings → login screen (sddm), then there is a button top right which says “apply plasma settings”. Once I ran through that, the configuration is correctly used on every boot just the way I want, login only appearing on the 2nd screen.
