Here are some updates regarding my GSoC 2012 project and the status of compat-drivers.
The aim of my project was to add support for backporting GPU/DRM kernel drivers to older kernels in a way similar to what has been done for Bluetooth/Ethernet/Wireless drivers in the compat-wireless project.
At the end of the summer, I was able to successfully build the three major DRM drivers, namely nouveau, radeon and i915 against kernels down to 3.2 but since I didn’t boot-test them, those were initially disabled in the tree.
After merging the work into a new tree called compat-drivers, my mentor Luis Rodriguez had the occasion of runtime testing the i915 driver on one of his machines and enabled the compilation of it for kernels >= 3.2.
This weekend I pushed a series of commits consisting of some bugfixes for the configuration scripts and some backport patches to the tree which finally enables nouveau (open-source reverse-engineered nVidia driver) and radeon (ATI/AMD GPU driver). Nouveau is built for kernels >= 3.3 and radeon for kernels >= 3.2.
If you ever test these drivers on your hardware, please report any problem to our backports mailing list.