radeon + laptop/external monitor (through docking station) problem

[Alex Deucher]

On Sun, Jun 15, 2008 at 9:40 PM, kewlemer <kewlemer at gmail.com> wrote:
> Hi all,
>
> My set up is basically a laptop connected to an external monitor
> through a docking station (Fedora 9 + AMD64).
>
> Laptop has a Radeon Mobility 7500 card (screen resolution 1280x800)
> and the external monitor is Samsung SyncMaster 225BW with 1680x1050
> resolution.
>
> The problem is that when I keep the laptop docked and access it
> through the external monitor, I get a display like this -
> http://picasaweb.google.com/kewlemer/XorgRadeonLaptopDockingStationExtMonitorProblem/photo#5212182196419140690

Since there are two screens of dis-similar size in clone mode, gnome
is picking the screen on crtc 0 as the default which is internal
panel.

>
> It looks like X incorrectly senses that both my laptop and monitor are
> plugged. Once logged in I can get rid of the smaller 1280x800 laptop
> screen boundary by doing a  -
> xrandr --output LVDS --off
>

They both are plugged in.

> Note that if I log in using KDE, it automatically adjusts to
> 1680x1050. GNOME however keeps what the login screen displays and I
> have to execute the above xrandr command to get rid of the smaller
> 1280x800 boundary.

I suspect KDE may reset the last setup you programmed or may choose
dimensions of the largest attached head or it may be using crtc 1.
Gnome may have similar options.

>
> Can some please tell me how to ensure that X starts with the right
> resolution when I boot from the docking station ? Once X throws the
> right screen size, GNOME would automatically use this and I wouldn't
> have to do the LVDS --off each time I log in. I have googled around
> and tried tweaking xorg.conf in different ways but no matter what I
> try it still displays the additional laptop screen laptop screen at
> bootup.

you can either add a monitor section and associate it with the LVDS
panel and then add:
Option "Disable" "TRUE"
This will disable the LVDS output by default, or, add the following
option to the device section of your xorg.conf:
Option "IgnoreLidStatus" "False"
this will attempt to use the acpi lid status to determine whether the
LVDS is "connected" or not.  Note, that on many systems the acpi bios
is busted and reports the wrong lid status.  that is why that option
is enabled by default.

Alex