blank external DVI on Thinkpad T40

[Alex Deucher]

On Wed, Feb 25, 2009 at 5:12 PM, Gilad Arnold <arnold at cs.berkeley.edu> wrote:
> On Wed, Feb 25, 2009 at 04:50:52PM -0500, Alex Deucher wrote:
>> Perhaps the panel doesn't like the pll or the modeline?
>
> I doubt it because the same modeline works with the RGB port (connected
> to the same monitor):

DVI is usually much pickier about modes than VGA.  you might try the
59.9 mode on the DVI:
xrandr --output DVI-0 --mode 1920x1200 --rate 59.9

>
> $ xrandr
> Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 1920 x 1200
> VGA-0 connected 1920x1200+0+0 (normal left inverted right) 546mm x 352mm
>   1920x1200      60.0*+   59.9
>   1600x1200      59.9
>   1680x1050      60.0
>   1600x1000      59.9
>   1280x1024      75.0
>   1280x960       59.9
>   1152x864       75.0
>   1024x768       75.1     60.0
>   832x624        74.6
>   800x600        75.0     60.3
>   640x480        75.0     60.0
>   720x400        70.1
> DVI-0 connected 1920x1200+0+0 (normal left inverted right) 546mm x 352mm
>   1920x1200      60.0*+   59.9
>   1600x1200      59.9
>   1680x1050      60.0
>   1600x1000      59.9
>   1280x1024      75.0
>   1280x960       59.9
>   1152x864       75.0
>   1024x768       75.1     60.0
>   832x624        74.6
>   800x600        75.0     60.3
>   640x480        75.0     60.0
>   720x400        70.1
> LVDS connected 1400x1050+0+0 (normal left inverted right) 0mm x 0mm
>   1400x1050      50.0*+
>   1280x1024      59.9
>   1152x864       60.0
>   1280x720       59.9
>   1024x768       60.0     59.9
>   800x600        60.3     59.9
>   640x480        59.9     59.4
> S-video disconnected (normal left inverted right)
>
>
>> Can you post your xorg log and config somewhere?
>
> http://play.cs.berkeley.edu/~arnold/xorg/
>
>> IIRC, I vaguely recall the ignore option doesn't work right.
>> shouldn't matter anyway as turning off LVDS using xrandr does the same
>> thing.
>
> It is not obvious (as a user) that the --off option removes the LVDS
> from the xorg layout entirely (i.e. deallocates video memory, etc). Or
> is it doing so?  Even after turning LVDS off the different modelines are
> still listed on subsequent xrandr calls. (In other words, setting a
> display to --off is different than pulling the cable out, what cannot be
> done with the laptop panel of course ;-) )

from the hardware's perspective they do the same thing: turn off the
output and disable the crtc driving it.

>
>> Multiple displays should work fine.  I think 1920x1200 on DVI worked
>> fine last time I tested on my rv250, but I can test again.
>
> I'd appreciate it if you can double check, and if it does send me your
> working config and software versions (xorg, radeon).

I'll take a look and let you know.

Alex