External monitor on a laptop with intel 945GM graphics

Jesse Barnes jbarnes at virtuousgeek.org
Tue May 15 16:58:09 PDT 2007

On Tuesday, May 15, 2007 4:23 pm Vedran Rodic wrote:
> Hi
> I have a Thinkpad X60 laptop that has Intel 945GM graphics
> controller. The native resolution of the LCD display of the laptop is
> 1024x768.
> I want to use an external CRT monitor with 1280x1024 at 85 HZ. I made
> this work on the included Windows XP easily, but I'm unable to set it
> up on Linux. I'm using the Debian unstable with xrandr 1.2 and intel
> driver 2.0. Running 'xrandr' returns:
> VGA connected 1024x768+0+0 (normal left inverted right) 0mm x 0mm
>    1280x800       60.0
>    1280x768       60.0
>    1024x768       60.0*
>    800x600        60.3
>    640x480        59.9
> LVDS connected 1024x768+0+0 (normal left inverted right) 246mm x
> 185mm 1024x768       50.0*+   60.0     59.9     40.0
>    800x600        60.3
>    640x480        60.0     59.9
> TV disconnected (normal left inverted right)
> I tried with latest xorg server and intel driver from git just in
> case, but the git version is only different so that xrandr doesn't
> return modes 1280x800 and 1280x768. I've tried customizing the
> xorg.conf file to make xorg only use the CRT, but it crashed. The
> xorg.log of that session is attached.
> I guess that the bios returning the resolution 1024x768 is what is
> confusing the driver.
> Ideally, I should be able to attach the monitor while xorg is
> running, xorg should read the edid data off the monitor and xrand
> should present me with a wide range of modes available for that
> monitor. I guess were not there yet for my particular configuration,
> but I'm ready to help in any way.

According to your log, the server isn't getting EDID data from the VGA 
port.  Maybe your monitor doesn't provide it?  If so, you'll have to 
add some custom modelines in order to get the resolution and refresh 
you want...


More information about the xorg mailing list