In early January was when Jerome published new R600-class 2D color tiling patches that support from the original Radeon HD 2000 series through the Radeon HD 6900 series. The R600 2D color tiling support is designed to deliver major performance boosts when it works correctly, but the initial support published last month was rather buggy. Since then, Glisse has worked a great deal on improving the 2D color tiling support.
Announced on the mailing list yesterday was completing the R600 2D color tiling support. Jerome believes the color tiling patches no longer cause any regresses -- including when using an older (unsupported) kernel -- and is ready for merging all of the patches. The ColorTiling2D option though still needs to be enabled within the xorg.conf for proper support. The 2D tiling covers the front-buffer and depth/stencil buffer.
Utilizing R600-class 2D color tiling requires patches to the Linux kernel, Mesa, libdrm, and the xf86-video-ati DDX driver. The kernel patches should land for the Linux 3.4 kernel, a new libdrm release is happening soon, and the Mesa-side Gallium3D patches will land for the Mesa 8.1 release this summer.
The performance-improving 2D color tiling support for the R300 through R500 (Radeon X1000) series support landed some time ago and is already enabled by default.