User-space API additions and changes (granted, no ABI breakage permitted for the mainline Linux kernel) to Linux Direct Rendering Manager (DRM) drivers is done fairly easily by their developers and possibly without enough thought. Linux DRM subsystem co-maintainer David Airlie has issued a proposal that would make user-space API alterations more strictly reviewed…

Source: Phoronix – Linux Graphics Drivers Could Have User-Space API Changes More Strictly Evaluated