[i945] [Xubuntu] wrong screen resolution after upgrade to Jaunty

Bug #366270 reported by Michal Kaut on 2009-04-24
This bug affects 2 people
Affects Status Importance Assigned to Milestone
xserver-xorg-video-intel (Ubuntu)

Bug Description

Binary package hint: xorg

After upgrade to Jaunty, Xubuntu starts with a wrong resolution on a laptop with external monitor.

hardware: HP Compaq nc2400, with i945 graphics card + Dell 1680x1050 screen, connected via docking station (so the laptop lid is closed all the time)

software: Xubuntu 9.04, i386; vanilla (untouched) xorg.conf

behaviour with intrepid: gdm uses 1024x768, but after login the screen switches to 1680x1050
behaviour with jaunty: screen stays in 1024x768 even after login

other observations:
- Settings->Display shows only one screen (Screen 1), but Settings->Desktop sometimes shows settings for both VGA and LVDS screens.
- I can choose the 1680x1050 resolution in Settings->Display and it works without problems.
- In Settings->Desktop, I have selected a different background pictures for VGA and LVDS. Then I see that after login the desktop starts with a background of the LVDS screen, not the VGA background. This is even more obvious if I add "xrandr --output VGA --auto" to gdm/Default - then I get the correct resolution (1680x1050), but I get the LVDS desktop drawn over the VGA one, i.e. there is the correct VGA 1680x1050 background picture, but over it there is drawn the smaller LVDS background picture (placed in the top-left corner of the screen). Looks xorg or xrand draws both screen on top of each other? .. could be a xrandr bug?
- I could not report this as a xrand bug using 'ubuntu-bug -p xrandr', as this results in a message that the package does not exist - which is wrong, as I can ran 'xrandr' command.
- Using the internal screen only (taking the laptop out of the docking station) works fine, using the correct resolution (1280x800).
- Probably not important, but under intrepid I had problem with the intel driver, with the system crash with a message about underrun on pipeB .. about once a day, with no reason I could see. I haven't yet seen it on Jaunty, but I have had it only a couple of hours..
- I installed grandr and in the Layout screen, both VGA and LVDS are in the middle box and neither can be moved anywhere. Also the "clone / extend" choice is grayed out - but that is probably correct, as the laptop lid is closed?

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 9.04
Package: xorg 1:7.4~5ubuntu18
ProcVersion: Linux version 2.6.28-11-generic (buildd@palmer) (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009
SourcePackage: xorg
Uname: Linux 2.6.28-11-generic i686

00:00.0 Host bridge [0600]: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub [8086:27a0] (rev 03)
     Subsystem: Hewlett-Packard Company Device [103c:30a1]
00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller [8086:27a2] (rev 03)
     Subsystem: Hewlett-Packard Company Device [103c:30a1]

Michal Kaut (michalkaut) wrote :
Bryce Harrington (bryce) on 2009-04-27
affects: xorg (Ubuntu) → xserver-xorg-video-intel (Ubuntu)
Bryce Harrington (bryce) on 2009-04-28
summary: - [Xubuntu, i945] wrong screen resolution after upgrade to Jaunty
+ [i945] [Xubuntu, i945] wrong screen resolution after upgrade to Jaunty
Bryce Harrington (bryce) on 2009-04-28
Changed in xserver-xorg-video-intel (Ubuntu):
status: New → Confirmed
Bryce Harrington (bryce) on 2009-05-06
tags: added: resolution
Bryce Harrington (bryce) on 2009-05-06
description: updated
Download full text (3.5 KiB)

Quick fix, in case someone has the same problem: add the following to /etc/gdm/Init/Default:
if xrandr -q | grep -q "VGA connected"; then
 xrandr --output LVDS --off --output VGA --auto

What it does: if an external monitor is detected, it will switch off the internal one and sets the monitor to its optimal resolution. An even better solution would be to set-up an extended desktop in the case the laptop lid is opened, but I do not know how to detect this...

More info about why this patch works

It looks like the original bug is a combination of two issues:
1. The system does not detect that the laptop lid is closed and starts with LVDS output on
2. When both LVDS and VGA outputs are on (and the lid is closed), they get both drawn on the main monitor, the LVDS being drawn over the VGA screen..

This can be illustrated by the following three versions of /etc/gdm/Init/Default. (Note that I am now running with an 1280x1024 external monitor, while the original post was done with 1680x1050 - but is should not make any difference):
I. no changes
- system (gdm) starts in 1024x768 resolution
- after login, I see the LVDS wallpaper
- xrandr -q gives:
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 1280 x 1280
VGA connected 1024x768+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024 60.0 + 75.0 60.0
   1152x864 75.0
   1024x768 75.0* 70.1 60.0
   832x624 74.6
   800x600 72.2 75.0 60.3
   640x480 75.0 72.8 59.9
   720x400 70.1
LVDS connected 1024x768+0+0 (normal left inverted right x axis y axis) 261mm x 163mm
   1280x800 60.0 +
   1024x768 85.0 75.0* 70.1 60.0
   832x624 74.6
   800x600 85.1 72.2 75.0 60.3 56.2
   640x480 85.0 72.8 75.0 59.9
   720x400 85.0
   640x400 85.1
   640x350 85.1
TV disconnected (normal left inverted right x axis y axis)
Note that LVDS is connected (even if the lid is closed) and that both LVDS and VGA have wrong resolution (which happens to be the biggest common resolution - is this a coincidence?)

II. /etc/gdm/Init/Default with added "xrandr --output VGA --auto"
- system starts with the correct resolution (1280x1024)
- I get the LVDS wallpaper drawn over the VGA one
- xrandr -q gives (deleted the lower resolutions lines for brevity):
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 1280 x 1280
VGA connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024 60.0*+ 75.0 60.0*
   1152x864 75.0
   1024x768 75.0 70.1 60.0
LVDS connected 1024x768+0+0 (normal left inverted right x axis y axis) 261mm x 163mm
   1280x800 60.0 +
   1024x768 85.0 75.0* 70.1 60.0
TV disconnected (normal left inverted right x axis y axis)

III. The fix from the start of this post
- everything works OK, assuming one has a closed lid
- xrandr -q output:
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 1280 x 1280
VGA connected 1280x1024+0+0 (normal left inverted right x axis y axis) 33...


Might be related to this, (it certainly seems like it), http://forum.xfce.org/index.php?topic=4989.0

Mine: HP 2510p.

Bryce Harrington (bryce) wrote :

[This is an automatic notification.]

A new major version of the -intel driver is now available in Karmic.

This version includes a major reworking of the acceleration
architecture, which resolves a huge number of issues. We do not know
whether it resolves the issue you reported.

Would you mind testing Karmic Alpha-2 and seeing if it is still a
problem? CD ISO images are available here:


If the issue can still be reproduced on karmic, please report here with
your findings, and attach a fresh Xorg.0.log from your test, and we will
be able to forward the bug upstream.

Otherwise, if the bug no longer exists in Karmic, let us know that as

In the off chance you encounter different bugs while attempting to test
Karmic, please report those as new bug reports.

Changed in xserver-xorg-video-intel (Ubuntu):
status: Confirmed → New
status: New → Incomplete

I can confirm that this occurs on my Dell Inspiron Mini 9 while attaching to a 22" external monitor.

The Dell Mini 9 has a native resolution of 1024x600.
The 22" external monitor has a native resolution of 1680x1050
The resolution that displays when they are connected to each other is 800x600.

I see that Bryce has stated their are brand new Intel drivers in Karmic, but what are the chances of this getting fixed in Jaunty?

Upon further inspection, it appears that 800x600 is the lowest-common-denominator when it comes to the screen resolutions of both monitors (according to "Display Preferences").

Dell Inspiron Mini 9
1024x600 (16:9)
800x600 (4:3)
640x480 (4:3)
720x400 (9:5)
640x400 (16:10)
640x350 (9:5)

KDS 22" External Monitor
1680x1050 (16:10)
1280x1024 (5:4)
1440x900 (16:10)
1024x768 (4:3)
800x600 (4:3)
640x480 (4:3)
720x400 (9:5)

Is there anyway to force, when mirroring, both monitors to 1024x600 so the widescreen monitor is less stretched?

I assume this method of finding the lowest-common-denominator is how the software is intended to work, but it looks pretty bad have the resolution of 800x600 stretched on a 22" monitor.

Geir Ove Myhr (gomyhr) on 2009-07-25
tags: added: 945gm
Bryce Harrington (bryce) wrote :

We're closing this bug since it is has been some time with no response from the original reporter. However, if the issue still exists please feel free to reopen with the requested information. Also, if you could, please test against the latest development version of Ubuntu, since this confirms the bug is one we may be able to pass upstream for help.

summary: - [i945] [Xubuntu, i945] wrong screen resolution after upgrade to Jaunty
+ [i945] [Xubuntu] wrong screen resolution after upgrade to Jaunty
tags: added: jaunty
Changed in xserver-xorg-video-intel (Ubuntu):
status: Incomplete → Invalid
Tom Bentley (tomcbentley) wrote :

Have Dell Inspiron Mini 10v and am running Ubuntu 9.04. Had kernel 2.6.28-16 and everything was fine after setting display to 1024x600 but with update of kernel to 2.6.28-17 the display is back to low graphics mode and will not let me reset it at all. Any ideas?

Vincent Fortier (th0ma7) wrote :

Having the exact same issue using 12.04 LTS.

Curiously enough it worked as expected for a little while (putting off the lvds and proper resolution on vga) but, perhaps due to an update, it now by default clone the lvds and force both screens to be 1024x768 (wich is probably the only compatible resolution between laptop & 22" lcd connected on vga.

Changed in xserver-xorg-video-intel (Ubuntu):
status: Invalid → Confirmed
Vincent Fortier (th0ma7) wrote :

Here is the adapter code snipet for 12.04 to add to /etc/gdm/Init/Default at the end of the file (but before the exit 0, of course):

if xrandr -q | grep "VGA[0-9] connected"; then
 VGA=`xrandr -q | grep "VGA[0-9] connected" | cut -f1 -d" "`
 LVDS=`xrandr -q | grep "LVDS[0-9] connected" | cut -f1 -d" "`
 [ "$VGA" ] && [ "$LVDS" ] \
            && xrandr --output $LVDS --off --output $VGA --auto

bugbot (bugbot) on 2012-04-05
tags: added: xubuntu
Chris Wilson (ickle) wrote :

Obsolete UMS bug.

Changed in xserver-xorg-video-intel (Ubuntu):
status: Confirmed → Fix Released
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