Dual Monitor issue -- one screen goes blank

[lykwydchykyn]

My setup is Maverick Meerkat 64bit, as of yesterday running KDE 4.6 (previously 4.5). I have a dual-head NVidia GeForce 8400 GS running in twinview, left monitor is my primary, right monitor is my secondary.

This worked flawlessly under Lucid, but since upgrading to Maverick, I started having an issue with the left monitor going blank for a few seconds when certain windowing functions were used. Mainly it happens when I launch virtualbox, or switch virtualbox between maximize/restore/minimize. It also happens with the "system settings" window. Any sort of window management activities with these windows causes the left monitor to go black for about 2 seconds, then come back.

The right monitor is unaffected. It makes no difference which monitor the window is on.

Since upgrading to 4.6, the issue has gotten worse. Any changes to my kwin configuration will cause the blanking.

Other window managers do not exhibit this behavior, so I assume it's a kwin issue.

Has anyone seen something like this happening?

EDIT: I should mention, I've tried defaulting my kwin settings and the same thing happens.

[poet_imp]

Re: Dual Monitor issue -- one screen goes blank

yes, I get the same thing, only for me it is the right hand monitor. So far, this is the only post I have been able to find with the complaint. I have been less successful in finding a solution...

[oshunluvr]

Re: Dual Monitor issue -- one screen goes blank

Anything in the logs? Post your xorg.conf files...

[poet_imp]

Re: Dual Monitor issue -- one screen goes blank

My video Card:

$ lspci | grep VGA
02:00.0 VGA compatible controller: nVidia Corporation G86 [Quadro NVS 290] (rev a1)

My xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 260.19.06 (buildmeister@builder101) Mon Sep 13 07:06:38 PDT 2010

# xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg
Section "ServerLayout"
Identifier "Default Layout"
Screen "Default Screen" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
EndSection

Section "Files"
EndSection

Section "Module"
Load "glx"
EndSection

Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "keyboard"
EndSection

Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "Monitor"
Identifier "PlanarPL1910"
Option "DPMS"
EndSection

Section "Device"
Identifier "nVidia Corporation NVIDIA Default Card"
Driver "nvidia"
EndSection

Section "Screen"
Identifier "Default Screen"
Device "nVidia Corporation NVIDIA Default Card"
Monitor "PlanarPL1910"
DefaultDepth 24
Option "TwinView" "true"
Option "TwinViewOrientation" "RightOf" # "LeftOf" "Above" "Below" "Clone"
Option "UseEdidFreqs" "True"
Option "MetaModes" "1280x1024,1280x1024"
Option "AddARGBVisuals" "True"
Option "AddARGBGLXVisuals" "True"
Option "NoLogo" "True"
SubSection "Display"
Depth 24
Modes "1280x1024" "1280x960" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
EndSubSection
EndSection

[oshunluvr]

Re: Dual Monitor issue -- one screen goes blank

Try adding these to your xorg.conf Device section:

  Option "TripleBuffer" "True" #Enables triple buffering. "Decreases the time an application stalls while waiting for vblank events, but increases latency slightly" (NVIDIA Readme) 
  Option "UseCompositeWrapper" "True" #Enables the X server's composite wrapper instead of the builtin one. 
  Option "BackingStore" "True" #Cache overlayed areas in case they get redisplayed later 
  Option "OnDemandVBlankInterrupts" "True" #Only fire VBlank interrupts in modes where they are needed

you could also play with "Vsync" options in nvidia-settings to see if that has any effect.

[poet_imp]

Re: Dual Monitor issue -- one screen goes blank

I tried it out first thing this morning. Alas, it did not make any noticeable difference.

I really think it is a KDE thing and not an nVidia thing. The driver did not change between 4.4(I think) with no problem and 4.5 with problem. The only thing that changed was KDE. It is like they are not managing the monitors independently instead of as a pair. For the OP the left monitor is the on that suffers the blanking and for me it is the right hand monitor. It seems to happen when I have another app start that wants to use OpenGL. (<--just guessing here)

Once the application is up all is good.

[oshunluvr]

Re: Dual Monitor issue -- one screen goes blank

I've not had this problem with KDE4 (4.2 through 4.5) at all so it's hard to say at this point what the issue is. Sounded like vsync/vblank issues but who knows?

Take your /var/log/Xorg.0.log file and copy it to your user, rename it to .txt and attach it to your next post.

[lykwydchykyn]

Re: Dual Monitor issue -- one screen goes blank

Don't know about poet_imp, but I get no errors in my Xorg.0.log, and I've watched the log while reproducing the error and no messages are logged when it happens.
Even so, here's my log, if it makes any difference.