Comment 12 for bug 394262

Patch to make driver compilable is here:
http://launchpadlibrarian.net/28552081/drm_agp_memory-2.6.31.patch

I successfully compiled nvidia 185.18.14 driver on kernel 2.6.31-1 with these commands:
cd /usr/src/nvidia-185.18.14/patches/
sudo wget http://launchpadlibrarian.net/28552081/drm_agp_memory-2.6.31.patch
sudo nano /usr/src/nvidia-185.18.14/dkms.conf

Add this line, save and exit:
PATCH[1]="drm_agp_memory-2.6.31.patch"

sudo dkms build -m nvidia -v 185.18.14 -k 2.6.31-1-generic
sudo dkms install -m nvidia -v 185.18.14 -k 2.6.31-1-generic