Bug#564645: fails to obtain EDID for 1 monitor in dual monitor setup

[Brice Goglin]

Steve M. Robbins wrote:
> Package: xserver-xorg-video-radeon
> Version: 1:6.12.4-2
> Severity: normal
>
> Just upgraded all packages today and rebooted into my first attempt at
> using xserver 1.7 and friends.
>
> I have an ancient Sony G400 CRT and a Syncmaster LCD attached to my card.
> I used to be able to run them in 1600x1200 and 1280x1024, respectively.
>
> Now, when X starts, the Syncmaster (DVI-1) is detected, but the Sony
> (DVI-0) is not.  Note also that "get-edid | parse-edid" fails to
> obtain data from the Sony:
>
> steve at riemann{~}xrandr
> Screen 0: minimum 320 x 200, current 2432 x 1024, maximum 3200 x 1200
> DVI-1 connected 1280x1024+1152+0 (normal left inverted right x axis y axis) 376mm x 301mm
>    1280x1024      60.0*+   75.0
>    1280x960       60.0
>    1152x864       75.0
>    1024x768       75.0     70.1     60.0
>    832x624        74.6
>    800x600        72.2     75.0     60.3     56.2
>    640x480        75.0     72.8     66.7     59.9
>    720x400        70.1
> DVI-0 connected 1152x864+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
>    1360x768       59.8
>    1152x864       60.0*
>    1024x768       60.0
>    800x600        60.3
>    640x480        59.9
>   

You should be able to work around the problem with Option Modeline and
PreferredMode in xorg.conf,
or xrandr --newmode and --addmode.

See III.5 and II.6 of http://wiki.debian.org/XStrikeForce/HowToRandR12

Brice