It's fairly rare these days seeing improvements to the xf86-video-ati DDX: the driver for those running a pre-AMDGPU (GCN 1.2) graphics card with this driver paired with Radeon DRM and not using the generic xf86-video-modesetting driver instead. But if you are using xf86-video-ati and use the "TearFree" feature to try to avoid screen tearing, a number of patches landed today.

Michel Dänzer of AMD landed a handful of patches to the xf86-video-ati Git repository today for the Radeon DDX. Notably the patches make for always allowing DRI2 page-flipping to be used with TearFree and the same goes for DRI Present page-flipping with the TearFree option. Long story short, page-flipping should now always work in the TearFree mode.

As a reminder of the TearFree option from the driver's man page, "Set the default value of the per-output 'TearFree' property, which controls tearing prevention using the hardware page flipping mechanism. TearFree is on for any CRTC associated with one or more outputs with TearFree on. Two separate scanout buffers need to be allocated for each CRTC with TearFree on."

The work is available via FreeDesktop.org Git.