External monitor on a laptop with intel 945GM graphics

JM Ibanez jm at orangeandbronze.com
Tue May 15 17:09:34 PDT 2007

"Vedran Rodic" <vrodic at gmail.com> writes:

> 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.

With the current X server, a Monitor section is assigned to each output;
by default, the "default" monitor is assigned to the first output, in
this case the VGA output.

Mode selection is then affected by the defined refresh rates for the
monitor. I've been hit by this before -- I had a monitor section with
a too low VertRefresh value, and so higher modes were being dropped by
the server as being too low.

Can you send your xorg.conf?

JM Ibanez
Software Architect
Orange & Bronze Software Labs, Ltd. Co.

jm at orangeandbronze.com

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