A Lot More Intel Tiger Lake / Gen12 Xe Graphics Code Merged To Mesa 19.3

With Mesa 19.3 embarking on its feature freeze this week unless the period is extended, Intel developers have been working on landing more of their Gen12 graphics code into this release for future Tiger Lake CPUs as well as the basis for their first Xe discrete graphics card.

For Mesa 19.3 is a lot of Intel's Gen13 graphics code bring-up to go along with their changes coming for Linux 5.5. For both kernel and user-space, it will likely be a few more releases each before the Gen12 graphics support is squared away, which should be fine since the first Xe graphics card isn't expected until H2'2020 and the same goes for the Tiger Lake CPUs with Gen12 graphics.

On top of all the early enablement work that was already merged for Gen12, this week there has been a lot of other extra code wired up particularly around compression support. The newest bit to land is confirmation of Gen12 supporting lossless compression with multi-samples during MSAA. "GEN12 adds the ability to losslessly compress each sample plane in a multisampled buffer that uses MCS compression."

HiZ CCS sampling and other HiZ bits have been merged for Gen12, which is important for performance.

And a lot of other code is now in place too, but still more than likely Mesa 20.0 will likely be around the base requirement where all the initial bring-up is in place for decent launch support. Mesa 20.0 is also the release where Intel is enabling the Iris Gallium3D driver by default -- though in the case of Gen12, only Iris Gallium3D is supported anyways for OpenGL.