gdm incorrectly configures multi-monitor displays

[Darren Adams]

Binary package hint: gdm

Using Maverick 10.10 betas

I have a dual monitor setup, and since updating to Maverick 10.10 (this never happened in 10.04), GDM cannot properly display the login screen when both monitors are plugged in. When only one monitors is plugged in, GDM correctly configures the display and the login screen appears. It's almost like GDM is trying to 'spread' the resolution of one monitor across both monitors, meaning that in my case where I have two monitors, both with a maximum resolution of 1600x900, GDM is either trying to:

1. Set up both monitors with a resolution of 800x900

2. Use a single resolution of 1600x900 and somehow make that work over both screens

I don't think this is related to the [Intel] xorg driver, as the attached xorg log indicates that both devices - VGA1 and DVI1 - are detected, and running startx does allow me to switch into a graphical session. There also seems to be no problem with drm (no warnings in the dmesg output).

Regardless, I'll attach output from the lspci, dmesg, and the xorg.log

Version of gdm is 2.30.5-0ubuntu4. I can't provide an xorg.conf file because my system doesn't have one (and didn't need one)

Of course, if there is anything else you would like me to provide, I'll try my best to do so
---
Architecture: amd64
DistroRelease: Ubuntu 10.10
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427.1)
Package: gdm 2.30.5-0ubuntu4
PackageArchitecture: amd64
ProcEnviron:
 LANG=en_GB.utf8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.35-22.33-generic 2.6.35.4
Tags: maverick
Uname: Linux 2.6.35-22-generic x86_64
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Darren Adams (darrengetsone)]

apport information

[Darren Adams (darrengetsone)]

Hrm, it looks like bug #646076 is related to this somehow. After creating the folders mentioned there, running the screen resolution capplet, then making the changes system-wide things seem better.

[Sebastien Bacher (seb128)]

it seems similar to bug #640807

[Darren Adams (darrengetsone)]

You could be correct. What's described at https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/640807/comments/2 as a workaround seems consistent with my none-too-scientific findings (i.e. disconnect a monitor to make GDM display the login window). I also attempted some of the things mentioned by other people that have made comments (such as disabling mode settings on my 965G, editing GDM configuration files) without much luck.

I would like to help with this where I can, and it looks like others are experiencing an issue similar to mine. Would it make sense for you to mark this bug a identical to the one you mentioned and continue reporting there?

[Sebastien Bacher (seb128)]

setting the bug as duplicate