Second monitor not working after qt6/kde6 upgrade

[beerbellyswan]

hi everyone - i upgraded my system to qt6/kde6 with no real problems, but now my primary monitor (of two) doesn't work after firing up kde. when i shut down my displaymanager, my primary monitor has my terminal and is working fine. but when i start up displaymanager (im using sddm), the primary monitor goes blank and the login screen starts up on my secondary monitor. I don't see any errors in the Xorg.log.0 or in my xorg-session.log logfiles, and both the NVIDIA Settings and the KDE Display settings look correct (both "see" my primary monitor with no errors). I'm happy to provide any system info or logs - but i've explored everything i can think of and can't find any trace of whats wrong. anyone have any ideas?

thanks!

[rab0171610]

I am still on stable, but I am going to assume that the newer SDDM still by default runs under X11 and that /usr/share/sddm/scripts/Xsetup is still a valid configuration file. You will have to verify that on your end. I would try:
https://blog.victormendonca.com/2018/06 ... e-screens/
You will need xrandr installed if it is not already.

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$ xrandr | grep ' connected'

You can then edit /usr/share/sddm/scripts/Xsetup, adding lines that pertain to your monitor setup.
For example, turn output DP-1 off during SDDM login screen:

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#!/bin/sh
# Xsetup - run as root before the login dialog appears

xrandr --output DP-1 --off

Then add the this one DisplayCommand= line to /etc/sddm.conf:

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[XDisplay]
# Xsetup script path
# A script to execute when starting the display server
DisplayCommand=/usr/share/sddm/scripts/Xsetup

Reboot.
As I said, something may have changed in the newer version (config files may be different, paths may be different, etc.) that would make this now obsolete. If that is the case I apologize. If not, then setting the displays explicitly for SDDM as described in this method should give you control over how SDDM is displayed in a multi-monitor setup under X11.
If you set it up correctly and you still have issues, then you can undo any changes you made and I would recommend that you file a bug report.

[jms.gentoo]

my primary monitor (of two) doesn't work after firing up kde.

NVIDIA

are you using the nvidia DVI output to connect to the primary monitor?
Are you using nvidia-drivers 555.58 ?
they are a few other hiccups with 555.58 depending on card.
have a look here
viewtopic-t-1169730.html

[beerbellyswan]

are you using the nvidia DVI output to connect to the primary monitor?
Are you using nvidia-drivers 555.58 ?
they are a few other hiccups with 555.58 depending on card.
have a look here
viewtopic-t-1169730.html

BOOM this is the problem! i didnt even notice that my nvidia drivers were being upgraded during the hundreds of other kde/qt packages being done so this didnt register with me. but that guys problem is exactly what i was experiencing so i downgraded to 550 and now im back in business. thanks a lot to both of you!