Comment 108 for bug 433142

Basically, the short answer to laptop support with the Geode X driver seems to be that it needs a custom xorg.conf for each laptop, since it cannot probe the display for ideal size.

Upstream developers have now documented this fact and provided command examples for calculating display modes along with a sample xorg.conf that shows how the command's result can be used. This will be included in xf86-video-geode 2.11.13 to be released shortly.