This bug was fixed in the package xserver-xorg-video-modesetting -
0.4.0-0ubuntu2
---
xserver-xorg-video-modesetting (0.4.0-0ubuntu2) quantal; urgency=low
* debian/patches/adding-platform-bus-support.patch:
- Adding platformBus support, to protect xorg on also loading the fbdev
Backport from upstream, adding the platformProbe hook, to properly work
when using it on ARM devices.
** Patch added: "xserver-xorg-video-modesetting_0.4.0-0ubuntu2.debdiff"
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-modesetting/+bug/1041727/+attachment/3277193/+files/xserver