Maintaining Out of Tree Drivers
"I'm trying to keep some external drivers up to date with the kernel, and the first two weeks after the release is the worst time for me. There is no way to distinguish the current git kernel from the latest release. It's only after rc1 is released that I can use the preprocessor to check LINUX_VERSION_CODE," explained Pavel Roskin, describing the ongoing effort to keep the out of tree MadWifi driver in sync with the latest released kernel.
Rik Van Riel suggested, "Consider this an incentive to submit your code for inclusion in the upstream kernel. Having all the common drivers integrated in the mainline kernel makes it much easier for users to use all their hardware, external drivers are not just a pain for the developers."