Mesa's Lima Gallium3D Driver Lands 4x MSAA Support

A decade after Luc Verhaegen started the Lima driver effort for reverse-engineering Arm Mali graphics, developers continue occasionally working on improvements to this Gallium3D driver for older generations of Mali hardware. The most recent feature work is finally enabling 4x MSAA support.

With Mesa 22.2 due out next quarter, the Lima Gallium3D driver now supports 4x multi-sample anti-aliasing (MSAA). The 4x MSAA is achievable with Mali's "Utgard" hardware that first debuted in 2007.

With this patch by Vasily Khoruzhick adding over one hundred lines of new code to the Lima driver, MSAA 4x support is working and GL_EXT_multisampled_render_to_texture is now exposed.

This follows Lima work from earlier this month switching over to a Lima-specific blitter. Lima in Mesa 22.2 is also now making use of NIR loop unrolling similar to the other drivers. This open-source driver continues improving even with the supported Arm Mali hardware advancing in age while Panfrost/PanVK also continues improving for the newer Mali spectrum of hardware.