AMDGPU GFX9+ Format Modifiers Being Worked On For Better DCC Handling

RADV Vulkan driver developer Bas Nieuwenhuizen of Google has ventured into kernel space in working on format modifiers support for Vega/GFX9 and newer.

This DRM format modifiers support for GFX9+ is being worked on for helping to evaluate when delta color compression (DCC) can be used and any other requirements around that DCC handling. Bas explained, "This is particularly useful to determine if we can use DCC, and whether we need an extra display compatible DCC metadata plane."

DCC is a big performance help so any improvements in this area are certainly enticing. RADV has already employed DCC for at least some GPUs / combinations while this format modifiers support should help them in ensuring its properly used.

More details via this patch message for the AMDGPU kernel change. Bas also has been working on the associated user-space format modifiers support to the common AMD code within Mesa.