[i965GM] GDM is starting up with wrong display resolution

[Johannes Langlotz]

Binary package hint: xserver-xorg-video-intel

I have a DELL Latitude D630 notebook with a d/port docking station and a DELL 2007wfp display which is connected to the docking station with a DVI plug. The notebook has a resolution of 1440x900. The external 2007wfp Display has a resolution of 1680x1050.

When I start the notebook not docked to the docking station everything is fine. GDM will show up with the native resolution of the notebook display.

But when the notebook is docked to the docking station, GDM will show up with a resolution both displays are capable to visualize. In my case this is 1024x768. Since this is a 4:3 mode and the displays are 16:10 ones, GDM will show-up blurry and stretched on both displays.

GDM should only be displayed on one display at a time:
1.) show GDM on external display only when notebook is docked and lid is closed
2.) show GDM on internal notebook display when notebook is undocked or when it is docked and lid is opened

[Bryce Harrington (bryce)]

Hi johannes-langlotz,

Thanks for including the attached files. Could you also include your /var/log/Xorg.0.log (or Xorg.0.log.old) from after reproducing the issue?

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[Geir Ove Myhr (gomyhr)]

If you remove your ~/.config/monitors.xml (if you have one) the resolution should be the same when you log in (IIRC). Could you in that case attach the output of `xrandr --verbose` both when docked and undocked.

[Johannes Langlotz (johannes-langlotz)]

Output of 'xrandr --verbose' after removing ~/.config/monitors.xml

[Geir Ove Myhr (gomyhr)]

It looks like my assumption about the resolution being the same after login was wrong, but at list we got the lists of available modes.

On http://intellinuxgraphics.org/2009Q2.html one of the items on the TODO list is to take the lid status into account. There is a corresponding bug report (with lots of duplicates): https://bugs.freedesktop.org/show_bug.cgi?id=11455 . Does it look like that upstream bug report is addressing your issue?

It seems a bit dangerous to me to only show the login screen on one of the detected monitor. Every now and then there are bugs where a monitor is detected when in fact there is none. Now, this only leads to wrong resolution, since the login screen is resized. It would be much worse if the login screen was only shown on the monitor which is in fact not there. See https://launchpad.net/ubuntu/+bugs?field.status%3Alist=NEW&field.status%3Alist=CONFIRMED&field.status%3Alist=TRIAGED&field.status%3Alist=INPROGRESS&field.status%3Alist=FIXCOMMITTED&field.status%3Alist=FIXRELEASED&assignee_option=any&field.omit_dupes.used=&field.tag=ghost-monitor&field.tags_combinator=ANY&search=Search for some of those bug reports.

Wouldn't it be an option to do the same thing as was the case in Hardy: both monitors use their native resolution, but their "desktop size" would be the least common denominator? See http://launchpadlibrarian.net/17844487/importdump.jpg for how this would look (taken from bug 273306 which had a non-existent VGA monitor) and http://launchpadlibrarian.net/12354400/screen.png for how the desktop then looked in mirror mode.

[Johannes Langlotz (johannes-langlotz)]

Yes, I think the upstream bug report addresses my issue.
When Windows XP shows the login screen on both displays it uses (the smaller) notebook resolution. This resolution is also shown on the external display, but not stretched (like ubuntu does it) but centered.

The best solution would be if I could switch between the displays (and perhaps mirror mode) with Fn+F8 (or whatever it is on other notebooks) when GDM is displayed. Just the way it is when logged in. When GDM is mirrored on both displays it should use the Windows approach (centering instead of stretching).