With Mesa 20.0 scheduled for branching today (though that could be delayed a few days potentially depending upon last minute requests), there's been a flurry of Radeon Vulkan "RADV" driver activity to squeeze into this first Mesa release series of 2020.

While Mesa 20.0 will be entering its feature freeze this week and branching ahead of the stable release expected in about one month, for now the Mesa 19.3 series is the newest available for stable users.

In addition to the AMD RadeonSI Gallium3D driver's on-disk shader cache and in-memory shader cache there is now a "live shader cache" to help with deduplication of compiled shader objects.

Mesa developers are planning to end feature work on Mesa 20.0 next week as this first quarter update to the Mesa 3D graphics stack.

The V3D Gallium3D driver that most notably offers the open-source graphics support for the Raspberry Pi 4 is now an official OpenGL ES 3.1 implementation.

The Valve-backed ACO compiler back-end that is optionally used by the RADV Radeon Vulkan driver has continued growing in popularity with Linux gamers and also has continued maturing a lot for Mesa 20.0 that is due out later this quarter.

There hasn't been a new Mesa stable release in a number of weeks due to the Christmas and New Year's holidays but that changed today with Mesa 19.3.2 as the first significant point release of Mesa 19.3.

The NIR intermediate representation is already faster than GLSL IR and TGSI but could be seeing even quicker linking speeds moving forward.

Zink was one of the Mesa/Gallium3D innovations that saw mainline status in 2019 for offering OpenGL support atop Vulkan hardware drivers. While an interesting approach, so far only the dated OpenGL 2.1 support has been exposed but the Collabora-led effort is closing in on OpenGL 3.0 capabilities.

Mesa3D as principally the collection of Linux OpenGL/Vulkan drivers is up to 2,996,270 lines of code (and documentation / associated scripts) within its Git tree! That should put it over the three million mark very soon while the Git activity was up by about 20% in 2019.

Similar to the trend with other Mesa drivers, the Radeon R600g driver for supporting Radeon HD 2000 through Radeon HD 6000 series graphics cards has been seeing experimental work to introduce a NIR back-end for this modern intermediate representation. That R600 NIR support now has a merge request open meaning it could possibly land still for Mesa 20.0.

Mesa 20.0 continues getting more interesting with the infrastructure around the Gallium3D LLVM "Gallivm" and TGSI IR now supporting tessellation.

Mesa's LLVMpipe Gallium3D driver has long been about running OpenGL on GPUs as a software fallback / debug path but as of this morning in Mesa 20.0-devel there is now the experimental ability of having OpenCL support making use of OpenCL "Clover" with NIR for CPU-based execution.

Joining the NIR driver bandwagon recently was LLVMpipe adding support for this new intermediate representation. Now with that support having matured, Mesa 20.0-devel's LLVMpipe software OpenGL driver is switching to NIR by default in place of TGSI.

While Mesa 19.3 was just released last week, Mesa 19.3.1 is now available rather than on its bi-weekly release cadence in order to avoid the Christmas and New Year's holidays.

The Broadcom V3D Gallium3D driver within Mesa 20.0 now has initial support for geometry shaders as needed by OpenGL ES 3.2.

After a few weeks worth of delays due to blocker bugs the release of Mesa 19.3 is out today as a big end-of-year upgrade to the open-source OpenGL and Vulkan drivers for Linux systems. Intel and AMD Radeon driver changes largely dominate the work as always but there is a growing number of embedded driver changes and other enhancements for this crucial piece to the open-source 3D ecosystem.

Mesa 20.0 due out in Q1'2020 is now the magical release that is set to switch on RadeonSI NIR usage by default in place of the TGSI intermediate representation. What makes this IR switch-over prominent is that OpenGL 4.6 is then enabled by default on this open-source Gallium3D driver supporting Radeon HD 7000 series GPUs and newer.

The TURNIP Mesa Vulkan driver providing support for recent Qualcomm Adreno graphics processors and akin to the Freedreno Gallium3D driver has added an important performance-boosting feature.

One of the most frequent complaints we hear from Linux gamers running open-source GPU drivers is over the lack of the hardware vendors supporting any feature-rich control panels like they do on Windows. There are many Linux driver tunables exposed by these open-source graphics drivers, but often they can only be manipulated via command-line options, environment variables, boot parameters, and other less than straight-forward means especially for recent converts from Windows and other novice Linux users. ADriConf has been doing a fairly decent job as a third-party means of helping to improve the situation and now there is talk of it supporting Vulkan driver settings.

As part of the ongoing effort for Intel's plans to use their new Gallium3D OpenGL Linux driver by default on next quarter's Mesa 20.0 for Broadwell "Gen8" graphics and newer, another step in that direction was achieved on Friday.

Even with the holidays fast approaching Mesa developers continue to be quite busy in landing new features ahead of next quarter's Mesa 20.0 release. The Lima Gallium3D driver and Turnip Vulkan driver are the latest benefiting from the Git code.

In addition to the discussion over potentially dropping non-Gallium3D drivers from Mesa or otherwise potentially forking a portion of the code, AMD's Marek Olšák made a separate proposal about renaming the Gallium3D "state tracker" concept to being "API" implementations.

Mesa 19.3 continues running behind schedule but stands chances for releasing next week if the lingering blocker bugs are closed.

Longtime open-source AMD graphics driver developer Marek Olšák has kicked off a discussion over the possibility in the not too distant future of either dropping non-Gallium3D drivers from Mesa (and moving them off to a maintenance branch or the like) or forking some of Mesa's existing code to allow it to be better optimized for Gallium3D use-cases. Due to raised concerns, other possibilities are also being expressed like simply moving ahead with optimizing the Mesa code-base for Gallium3D at a cost of potentially hitting dead code more often with the classic drivers.

The Panfrost Gallium3D driver that is the open-source OpenGL community-led driver for supporting Arm Mali Midgard/Bifrost architectures now has stable support for the T720 GPU.

While originally Intel planned to transition their OpenGL driver default to the modern "Iris" Gallium3D driver rather than the longstanding "i965" DRI driver for Mesa 19.3, that was pushed back to Mesa 20.0 for introduction in Q1'2020. In aiming to make that revised milestone a reality, a new option has been added to Mesa 20.0 with the Meson build system for being able to indicate the Intel OpenGL driver preference.

More Mesa drivers continue to be embracing NIR as the modern intermediate representation shared between these OpenGL and Vulkan open-source implementations.

While Mesa 19.3.0 was supposed to be out last week, it didn't happen nor is it happening this week due to blocker bugs. Given the US holiday week, it's looking like Mesa 19.3's blocker bugs might not be cleared in time for releasing next week either, but in any case the Mesa 19.3 Release Candidate 5 is now available for testing.

While the Radeon "ACO" compiler back-end performance is already looking very good in the speed department over the AMDGPU LLVM back-end for the Vulkan driver as shown in recent benchmarks, it's getting even better.