GNOME/Multiscreen

From openSUSE

Relatively few people have a Xinerama or multiscreen setup. This is where you have more than one monitor connected to your computer, and the desktop spans all the monitors.

Since few people have that kind of setup, we need volunteers to report bugs and test fixes for them. If you have a multiscreen setup, please write your name here!

How do I find out which driver I am using? grep -A4 -e 'drivers' /var/log/Xorg.0.log

Build service repository and project

Repository: Install everything from here

Project: For hacking

Known issues

All drivers

Currently, none of the X drivers support changing the screen's virtual size dynamically. This means that if you want to hotplug a monitor, you must first have an X server set up so that it will accept the size of your existing monitor plus the size of the new one.

Solution: Look in /etc/X11/xorg.conf for the "Display" subsection you are using. It may look something like this:

 Section "Screen"
   DefaultDepth 24
   ...
   SubSection "Display"
     Depth 24
     Modes "1400x1050" "1280x1024"
     Virtual 2840 1050
   EndSubSection
   ...
 EndSection

Take the sum of the sizes of your monitors. If you have a 1400x1050 LCD in your laptop, then plug an external monitor with size 1440x900, and want both displays to be joined one to the right of the other, you'll need a virtual size of 2840x1050. Add a line that says "Virtual horiz_resolution vert_resolution" to your "Display" subsection, as in the example above.

Make sure the Display subsection is the correct one for your DefaultDepth! The DefaultDepth from the Screen section must match the Depth from the Display subsection.

ATI

Old Radeon cards use the radeon driver (not radeonhd). We ship both the 6.6.3 driver as radeon and the 6.8.0 one as radeonrandr12. These tools require radeonrandr12 to work (as they need support for the RandR 1.2 X extension).

Solution: In /etc/X11/xorg.conf, change Driver "radeon" to Driver "radeonrandr12"

Action: Federico to ask the X team if we can use 6.8.0 instead by default.

Intel

Most laptops with an Intel chipset suffer from Bug #343858, so they think a VGA output is connected when it isn't. This shows up as gdm / gnome-panel being in the wrong place.

Nouveau

Laptops with nVidia chipsets may find that using the nouveau driver works best for them. Please be aware that this driver is still experimental and subject to various problems. Only use it if you know what you are doing. To enable RandR with nouveau, you need to edit /etc/X11/xorg.conf and find the "Device" section the relates to your card. It may look something like this:

 Section "Device"
   BoardName    "Quadro NVS 110M/GeForce Go 7300"
   BusID        "1:0:0"
   Driver       "nouveau"
   Identifier   "Device[0]"
   VendorName   "NVidia"
   Option       "Randr12" "true" 
 EndSection

You need to add the line in bold to the file, save and restart X.

Things to consider

• Ubuntu's patches to X for Intel 915
• Fedora is also working on this!

Multiple Displays Using XRandR

Multiscreen bugs

Bug #374148 - Tracker bug for multiscreen bugs

Related upstream bugs

• Icons are placed partly offscreen (panel 's struts for the window manager may be wrong) - This seems to happen with newer Intel drivers.

• Context menu doesn't work in Gedit's file browser plugin

Driver documentation

• Radeon
• RadeonHD

References

• Plans for RANDR 1.2 configuration in gnome-settings-daemon, gnome-control-center, and gnome-desktop (already in Fedora's and Ubuntu's development releases)