Mesa 19.2 R600 Gallium3D Can Advertise OpenGL 4.5 With Select GPUs
This Gallium3D driver is what provides Linux OpenGL support from the Radeon HD 2000 "R600" through Radeon HD 6000 (pre-GCN) series. Granted, only the Radeon HD 5800 and HD 6900 series is currently able to offer OpenGL 4.x support out-of-the-box with Mesa right now until the FP64 emulation support is all in place for being able to flip on GL_ARB_gpu_shader_fp64 that otherwise blocks OpenGL 4.0 support.
But if you are running an HD 5800/6900 series graphics card still, it's possible to hit OpenGL 4.5 with Mesa code in recent weeks. The last GL 4.5 blocker for R600g was the GL_KHR_robustness extension and that was taken care of. Confirmed in this commit that slipped under my radar until being pointed out by a Phoronix reader, R600 now marks GL 4.5 as "DONE."
While advertising OpenGL 4.5, the Radeon HD 5800/6900 series hardware is still too slow for playing most of today's modern Linux games (not to mention the newer game ports being Vulkan-based and using DXVK with Vulkan for Steam Play is a more performant experience, but pre-GCN hardware won't see a Vulkan driver) but it's nice that the milestone is finally reached.