At the beginning of last week I mentioned that a new X.Org Server API for drivers is coming that is the start of the work David Airlie has been doing to support GPU offloading (via DMA-BUF PRIME), USB device hot-plugging for graphics, and GPU switching between drivers for an active X.Org Server sessions, among other benefits. While the first set of API changes have landed, more work still needs to be pushed before all of the pieces of the puzzle for these much sought after features are landed and ready for use.
The patches by David Airlie began to land into the xorg-server this week, e.g. here, here, etc. With it hitting Git master of the xorg-server, the API changes will be introduced in the X.Org Server 1.13 release, which is scheduled for release in September.
These merged server-side patches are initially what had a hard time being reviewed, but eventually a few other X.Org developers took the time to review and sign-off on them.
With the xorg-server changes in place, support for the API changes have begun to propagate into the main DDX drivers. David Airlie has followed-up by committing support for the API changes to the DDX drivers. It begins by adding a new API compatibility header, using the new screen conversion APIs, and then compatibility for the new server API. It's a few hundred lines of changes, but compatibility with older X.Org Servers is maintained and there's a script to do much of the work automatically. This has happened already for the xf86-video-intel, xf86-video-ati, and xf86-video-nouveau drivers.