Laptop external monitor problem

[Alex Deucher]

On Dec 15, 2007 1:52 PM, Paul Morarescu <paul.morarescu at gmail.com> wrote:
> Hello,
>
> The newer driver versions seem to work better for me, but the only
> resolution I can get on my external 22" wide LCD is 1024x768. This is
> exactly the same as the native resolution of the LVDS screen. In fact,
> you will see below that xrandr behaves as if it drives both the LVDS
> and the VGA-0 ports in the same way. I need help to get the external
> monitor working at the optimum resolution of 1680x1050x60

For whatever reason, the driver is not able to get an edid from the
monitor, so it doesn't know what modes the monitor supports, hence it
ends up with the default monitor ranges which means 1024x768 at 60.

>
> Section "Monitor"
>         Identifier "LVDS-display"
> EndSection
>
> Section "Monitor"
>         Identifier      "ProView"
>         HorizSync       30.0-81.0
>         VertRefresh     55.0-77.0
> EndSection
>
> Section "Device"
>         Identifier  "Videocard0"
>         Driver      "radeon"
>         #Option     "DefaultConnectorTable" "on"
>         #Option      "ConnectorTable" "5,2,2,1,3,1,0,2"
>         #Option "ReverseDDC" "true"
>         Option      "LVDS"   "LVDS-display"
>         Option      "VGA-0"  "ProView"
> EndSection

The above options are wrong.  They should be:
         Option      "monitor-LVDS"   "LVDS-display"
         Option      "monitor-VGA-0"  "ProView"

See this page for more on randr 1.2 xorg configuration.  If you want
1680x1050 on the external monitor, you'll have to set that as the
preferred mode in your "ProView" monitor section.
http://www.intellinuxgraphics.com/dualhead.html

Alex