1600x1200 not working on T42(Mobile 9000) DVI

[Alex Deucher]

On Wed, Sep 23, 2009 at 12:20 PM, Che-Wei Chang <mailcwc at gmail.com> wrote:
> I installed Ubuntu 9.04 on IBM T42 with ATI Mobile 9000 chipset.
> The T42 is connected to an external monitor, Dell 2007FP, through DVI cable.
> The native resolution of 2007FP is 1600x1200.
>
> I set up dual monitors with build-in System/Preferences/Display.
> The display panel detected the 2007FP, and showed that it can work on
> 1600x1200 mode.
> However, the external monitor turned to power saving
> while I changed the display mode. In the mean time, T42 screen works.
>
> The dual monitors mode works OK when I lower the resolution of 2007FP
> to 1280x1024, 1152x864, or 1024x768. Then, I turned off T42 monitor in
> the display panel, and turned 2007FP to 1600x1200, still not working.
> Therefore, I think this should be due to the video driver, not the
> configuration.
>
> I googled dual monitor set-up, and found there is a bug in kernel
> 2.68.28, then I upgraded kernel to 2.68.30. However, not luck here.
> Following is information given from xrandr with 1152x864 mode.
>
> Screen 0: minimum 320 x 200, current 2176 x 864, maximum 2176 x 1632
> VGA-0 disconnected (normal left inverted right x axis y axis)
> DVI-0 connected 1152x864+0+0 (normal left inverted right x axis y
> axis) 367mm x 275mm
> 1600x1200 60.0 +
> 1280x1024 75.0 60.0
> 1152x864 75.0*
> 1024x768 75.0 60.0
> 800x600 75.0 60.3
> 640x480 75.0 59.9
> 720x400 70.1
> LVDS connected 1024x768+1152+0 (normal left inverted right x axis y
> axis) 0mm x 0mm
> 1024x768 60.0*+ 60.0
> 800x600 60.3 59.9
> 640x480 59.9 59.4
> S-video disconnected (normal left inverted right x axis y axis)
>
> Any suggestion?

IIRC, the DVI port on the thinkpad dock is limited to 1280x1024.

Alex