Mesa 21.3-rc4 Release Led By Many Zink Fixes

Mesa 21.3 as the final feature release for this collection of open-source OpenGL and Vulkan drivers isn't yet ready to go as some blocker bugs persist, but available now is the fourth weekly release candidate.

Blocking Mesa 21.3 still are regressions affecting various dEQP failures, a regression breaking builds for all non-Linux platforms like macOS / BSDs / Solaris / Haiku / Cygwin / Hurd, Piglit test failures, and a rendering issue with Tomb Raider paired with RadeonSI Gallium3D.

There are just under three dozen changes with Mesa 21.3-rc4 while over half of them are Zink Gallium3D fixes. That Zink OpenGL-on-Vulkan implementation has been seeing many fixes recently, 17 of which were back-ported for Mesa 21.3 this week. Upstream Mesa 22.0-devel in fact is close to reaching OpenGL 4.6 conformance for Zink and more OpenGL games continuing to work with ease for this "driver".

Aside from all the Zink patches, RADV has a fix to disable its coherent L2 cache optimization on cards with non-coherent L2, Lavapipe is no longer advertising EXT_acquire_xlib_display, RadeonSI has enabled shader culling for indirect draws, and various other minor fixes.

The list of Mesa 21.3-rc4 changes can be found via the release announcement.

Mesa 21.3 is bringing many driver improvements ranging from RADV ray-tracing support in experimental form to RADV NGG culling, OpenGL ES 3.2 for Zink, and more.