Intel "Crocus" Gallium3D Now Part Of Mesa's Default Drivers To Build
Intel's i965 classic DRI driver is still the default within Mesa for i965 through Haswell generations of Intel integrated graphics, but the new "Crocus" Gallium3D driver has been added to the default driver build list so it's now at least building by default on x86/x86_64 systems and thus trivial after that to override.
Crocus has come about nicely in a matter of months for providing an open-source Gallium3D driver for i965 through Haswell generations. Intel's Iris Gallium3D driver continues to be the official and default driver for Broadwell graphics and newer, but thanks to the community Crocus is now viable for older generations especially as Mesa developers have expressed possible interest in phasing out classic driver support in the future.
The open-source driver support for old hardware continues to improve.
Since being added to mainline Mesa earlier this year, the Crocus performance has been quite good relative to the i965 classic driver. For most use-cases, Crocus should be similar or better off than the classic driver.
Crocus though still isn't the default driver, but at least now for Mesa 21.3 is added to the default group of Gallium3D drivers for x86/x86_64. So unless overriding the Gallium3D driver list, Crocus will be built/installed moving forward. The i965 classic driver though is still in mainline, so unless opting out of that build, MESA_LOADER_DRIVER_OVERRIDE=crocus is still needed to force this Gallium3D driver to be used for OpenGL / OpenGL ES. In any case just changing the environment variable is easier than potentially having to rebuild Mesa if your distribution/packages are sticking to those defaults.
Hopefully in the future we'll see Crocus used by default for pre-Broadwell hardware and the i965 classic driver can be removed from the tree.