Ben Widawsky of Intel's Open-Source Technology Center announced the new Broadwell temporary branch for delivering changes faster and easier while the hardware enablement is taking place.
In response to the demand for Broadwell features and fixes which are not yet merged in our upstream drm-intel repository I will be maintaining a branch in my freedesktop repository with some of the features and fixes that I have been using myself.This temporary Git branch can be found in Ben's FreeDesktop.org Git repository. The changes tacked into this repository include Broadwell hardware semaphore support, 4GB GGTT + PPGTT clean-ups, RC6 power-savings support, frame-buffer compression (FBC) support, and random fixes. Coming soon should also be Broadwell run-time power-savings support.
Platform branches have not worked particularly well for us in the past, and I am hopeful that the repository will be [extremely] short lived because many of the patches I am keeping are either obvious fixes, or decently reviewed patch series. At the very least it will be maintained until Daniel returns from vacation next week (but I do expect it to last at least a few weeks past that).
The branch will be a rebasing branch from the upstream drm-intel-nightly, and should not be expected to be as stable as upstream Broadwell support. Please only use this if you need to use a specific feature, or fix in the branch.
So this kernel branch has extra features for power management and performance on Intel's next-generation Broadwell hardware. Expect most of these changes to land in the Linux 3.15 kernel. The timing of these features landing late will hopefully not be too much of a big deal for end-users since it looks like Intel Broadwell CPUs won't be shipping now until late Q3 or even into the fourth quarter.