gnome-display-properties/xrandr crashes X server when loading after pluging an external display

[Quentin Lampin]

Binary package hint: gnome-control-center

release: ubuntu 9.10
package: gnome-control-center 1:2.28.1-0ubuntu1

related information:

00:02.0 VGA compatible controller: Intel Corporation Mobile 945GME Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)

xserver-xorg: 1:7.4+3ubuntu7
xserver-xorg-video-intel: 2:2.9.0-1ubuntu2
libxrandr2: 2:1.3.0-2

How to reproduce the bug:
start your computer (laptop) without any external display plugged in.
Let your Gnome session starts.
plug the VGA cable in.
launch gnome-display-properties.

What's happening:
X crashes (freeze).

relevant Xorg.0.log entries: (at the end of the file)
""
(II) intel(0): Allocate new frame buffer 2704x1050 stride 4096
""

What strikes me is that the intel driver is told to allocate a 2704*1050 FB whereas specs available at
http://www.intel.com/design/mobile/specupdt/309220.htm page 375 state that maximum resolution is 2048x1536.

What's expected:
Well, the gnome-display-properties window is expected.

More information:
-Starting X with the external display already plugged in works, ie: I can launch gnome-display-properties.
-if you reproduce the bug process and change the call to gnome-display-properties by a call to xrandr, same bug occurs

ProblemType: Bug
Architecture: i386
Date: Fri Oct 23 20:22:07 2009
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/bin/gnome-display-properties
Package: gnome-control-center 1:2.28.1-0ubuntu1
ProcEnviron:
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: gnome-control-center
Uname: Linux 2.6.31-14-generic i686

[Sebastien Bacher (seb128)]

xserver crashing is an xserver issue whatever the software do it should not crash

[HannesB (hannesb)]

Reproduced on EEEPC 1000H (same GPU)
gnome-display-properties -> crash
You can even crash it by just typing
"xrandr" in a console after plugging in an external screen.
Screens get black and the mouse pointer is visible but stucked.

Tried with a shorter VGA-cable:
gnome-display-properties: X-Server does not crash at all, both screens get black, it chooses
a side by side desktop view (also i didnt tell him), i can move mouse from the left to the right, no desktop elements accessible, but on the left
corner I can see a 2-3 pixel wide stripe of my desktop but I cannot access anything,

after that I can recover with my self-configured hotkey: xrandr --output LVDS1 --auto --output VGA1 --off
Then I find the propperties and can configure it correctly either by th GUI or by another xrandr call

typing xrandr after reboot,plugging in results also in those two black screens

After having the screen succesfully set up once, I can reconnect it as often as I like

My questiones:
-why does my system change the screen setup without me asking it to do so????
-why does my system crash if the VGA-Cable is too long (and it maybe cannot read monitor settings propperly?)

I hope to have given some hints...
9.04 just worked perfectly....