DRI3 v1.2 Lands In X.Org Server 1.20
Along with the X.Org Server bits are support within the modesetting DDX driver and GLAMOR acceleration for the new DRI3 v1.2 capabilities. This includes support for multiple planes and buffer modifier requests. The modesetting DDX work includes atomic mode-setting support and supporting buffer formats/modifiers. The multi-plane support should be particularly useful for ARM/embedded Linux devices.
At the moment xf86-video-modesetting is the only DDX driver implementing DRI3 v1.2 but will be interesting to see what other ones do (or don't) for X.Org Server 1.20 now that most users/developers are focusing on the generic mode-setting DDX with GLAMOR acceleration rather than relying upon the vendor-specific DDX drivers.
These post-RC1 additions for X.Org Server 1.20 can be found via the xserver Git. These DRI3 additions were led by Louis-Francis Ratté-Boulianne of Collabora.