Dual monitors issue

Support Graphics & Display
1

DUAL MONITORS ISSUE

After this update

i rebooted the pc and the system switched my 2 monitors: the main became the secondary and viceversa.
I use LXQt with KWin, the graphics card has 3 outputs: HDMI (main monitor fullHD), DVI (secondary monitor 1680x1050) and VGA (not connected).
I tried to solve this using xrandr and the monitor settings in the Settings,
pic1

but nothing changed.
I switched from KWin to Openbox and with xrandr it works but temporarily (anyway the system bar keeps staying in the secondary monitor, i have to change its settings manually), if i reboot the section or the pc, monitors switch again.
It seems that the system is not able to save the settings.
To get a standard view i have to open monitor settings in the Settings and set the monitors, then i execute a script (that switches the monitors), then i have to change the settings of the main panel, cause it is always in the second monitor.

The last update

doesn’t solve the problem.

Any help or ideas? (If you need any output please post the command you need, thanks)

The last working lxqt-config-monitor.conf settings is (i omitted some values):

SavedSettings\31\date=2023-01-05T13:48:44
SavedSettings\31\name=gio gen 5 13:48:44 2023
SavedSettings\31\settings\1\connected=false
SavedSettings\31\settings\1\hash=
SavedSettings\31\settings\1\name=DisplayPort-0
SavedSettings\31\settings\2\connected=true
SavedSettings\31\settings\2\currentMode=87
SavedSettings\31\settings\2\currentModeHeight=1080
SavedSettings\31\settings\2\currentModeRate=@Variant(\0\0\0\x87\x42p\0\0)
SavedSettings\31\settings\2\currentModeWidth=1920
SavedSettings\31\settings\2\enabled=true
SavedSettings\31\settings\2\name=HDMI-A-0
SavedSettings\31\settings\2\primary=true
SavedSettings\31\settings\2\rotation=1
SavedSettings\31\settings\2\xPos=0
SavedSettings\31\settings\2\yPos=0
SavedSettings\31\settings\3\connected=true
SavedSettings\31\settings\3\currentMode=90
SavedSettings\31\settings\3\currentModeHeight=1050
SavedSettings\31\settings\3\currentModeRate=@Variant(\0\0\0\x87\x42o\x88s)
SavedSettings\31\settings\3\currentModeWidth=1680
SavedSettings\31\settings\3\enabled=true
> SavedSettings\31\settings\3\name=DVI-D-0
> SavedSettings\31\settings\3\primary=false
SavedSettings\31\settings\3\rotation=1
SavedSettings\31\settings\3\xPos=1920
SavedSettings\31\settings\3\yPos=0
SavedSettings\31\settings\size=3

after the update the lxqt-config-monitor.conf is:

SavedSettings\32\date=2023-04-02T07:25:15
SavedSettings\32\name=dom apr 2 07:25:15 2023
SavedSettings\32\settings\1\connected=false
SavedSettings\32\settings\1\hash=
SavedSettings\32\settings\1\name=DisplayPort-0
SavedSettings\32\settings\2\connected=true
SavedSettings\32\settings\2\currentMode=87
SavedSettings\32\settings\2\currentModeHeight=1080
SavedSettings\32\settings\2\currentModeRate=@Variant(\0\0\0\x87\x42p\0\0)
SavedSettings\32\settings\2\currentModeWidth=1920
SavedSettings\32\settings\2\enabled=true
SavedSettings\32\settings\2\name=HDMI-A-0
SavedSettings\32\settings\2\primary=true
SavedSettings\32\settings\2\rotation=1
SavedSettings\32\settings\2\xPos=0
SavedSettings\32\settings\2\yPos=0
SavedSettings\32\settings\3\connected=true
SavedSettings\32\settings\3\currentMode=90
SavedSettings\32\settings\3\currentModeHeight=1050
SavedSettings\32\settings\3\currentModeRate=@Variant(\0\0\0\x87\x42o\x88s)
SavedSettings\32\settings\3\currentModeWidth=1680
SavedSettings\32\settings\3\enabled=true
> SavedSettings\32\settings\3\name=DVI-D-0
> SavedSettings\32\settings\3\primary=true
SavedSettings\32\settings\3\rotation=1
SavedSettings\32\settings\3\xPos=1920
SavedSettings\32\settings\3\yPos=0
SavedSettings\32\settings\size=3

As you can see the second monitor is identified as DVI and primary true, when before it was identified as primary false.
Basically the system sets the 2 monitors, both as primary true.
Does anybody know which package is responsible for that?

2

I don’t know the answer, but lately Plasma changed how the multimonitor system works entirely, so when you use two DEs, there might be conflicts and one will overwrite the other. If possible, I would get rid of LXQT components that detect and set monitors, use Kwin again and see if the issue still occurs.
You can also set a test user with default settings, log in and see if the issue occurs there as well. If not, the problem is with your configs on user space. If the problem is still there, it’s some upstream issue or conflict with packages. I suspect that if Plasma devs came out with stable and modern monitor managing system, they didn’t take other DEs into account, since mixing DEs is rather rare nowadays and not encouraged. Ironically, LXQT is a DE that works quite well with Kwin, but I guess the new settings may have a problem with it.

3

Ok i got this solution from LXQt GitHub:

anyway, michaldybczak answer (Dual monitors issue - #2 by michaldybczak) can be tested too.
If anybody else has a better solution, is welcome.

1 Like
4

This topic was automatically closed 2 days after the last reply. New replies are no longer allowed.