How to stop KDE from changing the screen resolution

display-settingskdemulti-monitor

I am running Linux Mint 17 with KDE and display drivers from Nvidia. I've configured the display settings using nvidia-settings, and when I first start up everything appears to work correctly.

However, when I log in and KDE is loaded, it does something to my display setup which turns off one of my three connected screens. Using the KDE Display settings I am unable to turn the screen back on, but restarting the session and returning to the login screen shows the login dialog on this screen as intended.

How do I stop KDE from messing with my screen setup? Alternatively, why is one of my monitors getting turned off? FWIW, the monitor affected by this is connected via HDMI while the other two that keep working are using DVI.

Best Answer

There's a module in KDE called KScreen that is doing this.

To disable it, go to K Menu->Computer->System Settings->System Administration->Startup and Shutdown->Service Manager. Look for a service called KScreen, and uncheck the Use box. You can stop the service now if you want.

You can also manually edit $HOME/.kde/share/config/kdedrc, and add these lines:

[Module-kscreen]
autoload=false

This stops KDE messing with monitor configurations, and will stick with the one KDM provided at startup.

Kscreen is a per-user service; you'll need to set it for every user unless you have a policy set up.

Related Solutions

How to change the default “fullscreen” monitor

While I haven't been able to actually keep both screens enabled, I can at least map games to the correct screen. What I did was change the 'metamode' line in xorg.conf:

Option         "metamodes" "CRT: 1280x1024 +1920+180, DFP: nvidia-auto-select +0+0; DFP: 1920x1200, CRT: NULL"

I'm not entirely sure what the first part does, it was autogenerated by nvidia-settings. The second part however instructs the driver to realize a request for 1920x1200 resolution -- the native resolution of my primary screen, DFP -- by disabling the secondary one (CRT).

Those games that were well-behaved to begin with never actually changed the resolution to begin with but instead created a full-screen sized borderless window and placed it on the primary screen.

EDIT: This doesn't work as well as I thought, the mode isn't switched back properly later.

X11 Monitors – Handle Unlisted Screen Resolution

first run

$ xrandr

this will give output like this:

Screen 0: minimum 320 x 200, current 5120 x 1080, maximum 8192 x 8192
HDMI1 connected 2560x1080+2560+0 (normal left inverted right x axis y axis) 677mm x 290mm 
   1920x1080     60.00*  
   1680x1050     59.88  
   1600x900      59.98  
...

HDMI2 connected 2560x1080+0+0 (normal left inverted right x axis y axis) 677mm x 290mm
   2560x1080     60.00*+
   2560x1080_60.00  59.98  
   1920x1080     60.00    50.00    59.94    30.00    29.97  
   1920x1080i    60.00    50.00    59.94  
...

to add 2560x1080 to HDMI1 first run the next command

$ cvt 2560 1080

sample output:

2560x1080 59.98 Hz (CVT) hsync: 67.17 kHz; pclk: 230.00 MHz
Modeline "2560x1080_60.00"  230.00  2560 2720 2992 3424  1080 1083 1093 1120 -hsync +vsync

now you need to use this output to test the resolution and than add the settings for use in the next sessions.

testing:

$ xrandr --newmode "2560x1080_60.00"  230.00  2560 2720 2992 3424  1080 1083 1093 1120 -hsync +vsync
$ xrandr --addmode HDMI1 2560x1080_60.00
$ xrandr --output HDMI1 --mode 2560x1080_60.00

if it works you can add it to the xorg configuration

$ sudo vim /etc/X11/xorg.conf.d/40-monitor.conf

$ sudo vim /usr/share/X11/xorg.conf.d/40-monitor.conf

Section "Monitor"
    Identifier "HDMI1"
    Modeline "2560x1080_60.00"  230.00  2560 2720 2992 3424  1080 1083 1093 1120 -hsync +vsync
    Option "PreferredMode" "2560x1080"
EndSection

Best Answer

Related Solutions

How to change the default “fullscreen” monitor

X11 Monitors – Handle Unlisted Screen Resolution

Related Question