Screen resolution incorrectly detected with external monitor in kde4

[Tom Haddon]

Binary package hint: kubuntu-kde4-desktop

My laptop has a screen that is 1280x800. I have an external monitor plugged in that is 1680x1050. It seems that kde4 is somewhat confused about the resolution of my display (please see screenshot).

I'm using Hardy beta (with latest updates as of 2008-04-03) i386. It seems I have version 0.13 of kubuntu-kde4-desktop.

[Brian Harkness (maestro-bwh)]

I have a similar issue, both with hardy and with gutsy.

If my laptop is connected to an external monitor of a larger size, kdm-kde4 looks fine, and seems to understand to clone the screen and make the external monitor go to its full resolution. The laptop shows a portion of the screen (virtual)

When kde4 loads, it oddly places the laptop "desktop" on top of the "desktop" created for the external screen. The panel ends up being at the base of where the bottom of where the laptop's desktop would be: and goes only as far left as the laptop display permits. The wallpaper looks like a photo was placed on an identical larger one.

Plasma items can be placed on the desktop, but if slid to the area where the smaller area is, they disappear underneath it. An item on the smaller area, i.e. a picture frame, it can be dragged onto the "extended" desktop... just not vice versa. Two wallpapers actually exist: one for the smaller and one for the larger. Very weird artifacts... it is usable, just not how it should be.

If I boot into KDE3, everything configures properly.

[Brian Harkness (maestro-bwh)]

--> additionally: If systemsettings --> display is slected, the screen flickers and falls back to the lowest resolution and the desktop renders poorly on the external display. After this, the dialog for the display applet loads but "apply" is not highlighted and therefore, no changed can be made to take effect. Even launching this in root has the same effect, no ability to apply changes. One must restart X.

The graphical version of xrandr doesn't seem to load from the menu so I have yet to try to configure this from the command line. I tried once and I could never get my external display back up to the 1280x1024. Renamed /home/{username}/.kde4 to /.kde4old and logged out/in and the default desktop loaded, and I could copy the "plasma" related from the old .kde4 config directory to the new one and my desktop was back to the way I had set it up before this debacle. I add this just in case someone "ruins" their desktop and wants to restore it. There might be an easier way by editing some config file.

[Pavel Novak (pavel-innuendo)]

I can confirm this with KDE4. The same problem is with mplayer too. If I play movie with -vo xv -fs (fullscreen), the video is fullscreened just to 1280x800 (internal screen resolution) not to real 1650x1080.

[Brian Harkness (maestro-bwh)]

I fixed my issue (It might also help someone resolve this issue on a deeper level)

This probably won't be a solution for most people because I have kubuntu-kde4 installed on an external usb device that I ONLY use when hooked up at home via a KVM switch to an external monitor. In the event that you WILL NOT use your internal LVDS monitor for kde4, you can do the following to make the desktop on the external monitor work properly:

Back up your /exc/X11/xorg.conf

run in konsole, while logged into KDE4 with YOUR EXTERNAL MONITOR ATTACHED.

sudo dpkg-reconfigure -phigh xserver-xorg

Make sure your /etc/X11/xorg.conf has a similar addition: I had to add:
        Option "monitor-VGA" "SyncMaster"
 Option "monitor-TV" "TV"
 Option "monitor-LVCD" "LVCD":

and associated monitors

Example:
Section "Device"
 Identifier "Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller"
 Driver "intel"
 BusID "PCI:0:2:0"
        Option "monitor-VGA" "SyncMaster"
 Option "monitor-TV" "TV"
 Option "monitor-LVCD" "LVCD"

EndSection

Section "Monitor"
 Identifier "SyncMaster"
 Option "DPMS"
EndSection

Section "Monitor"
 Identifier "TV"
 Option "Ignore" "true"
EndSection

Section "Monitor"
        Identifier "LVCD"
 Option "DPMS"
        Option "Ignore" "true"
EndSection

Then add this to the beginning your /home/user/.bashrc
xrandr --output LVDS --off

You can leave it at that and log in/out and the panel is fixed, but anything in the system tray won't show and your desktop will still look weird,

so if you are willing to LOSE YOUR DESKTOP SETTINGS:
while logged out of KDE4 so rename your old /home/user/.kde4 directory to something (i.e. .kde4old), then log back in.

[Yuriy Kozlov (yuriy-kozlov)]

I just ran into this as well. I set up an external monitor (1600x1200) to clone my laptop screen (1400x1050) with nvidia-settings. All was well until I went to display in System Settings. Then I got what's in the screenshot here. Going to nvidia-settings and changing the resolution to 1400x1050, then back to 1600x1200 fixed it.

[Pavel Novak (pavel-innuendo)]

Still problem with KDE 4.1 on Kubuntu 8.04 and devel branch Kubuntu 8.10. See screenshot.

> xrandr ~
Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 1680 x 1680
VGA connected 1680x1050+0+0 (normal left inverted right x axis y axis) 473mm x 296mm
   1680x1050 60.0*+
   1280x1024 59.9
   1440x900 59.9
   1280x960 59.9
   1152x864 74.8
   1024x768 75.1 70.1 60.0
   832x624 74.6
   800x600 72.2 75.0 60.3 56.2
   640x480 75.0 72.8 66.7 60.0
   720x400 70.1
LVDS connected 1366x768+0+0 (normal left inverted right x axis y axis) 246mm x 139mm
   1366x768 60.0*+
   1280x768 60.0
   1024x768 60.0
   800x600 60.3
   640x480 59.9
TV disconnected (normal left inverted right x axis y axis)

[Jonathan Thomas (echidnaman)]

Not a bug in the kubuntu-kde4-desktop package -> invalidating the kubuntu-kde4-meta task.