There are already separate branches of the xf86-video-radeonhd driver
for AtomBIOS support
and another one for improved 2D acceleration, but today we have yet another branch. This new branch is called "CS" and what it does is change all calls within the driver for the command sequences (the "CS") into macros.
As Luc Verhaegen explained in his mailing list message
, inline functions should yield the same performance as macros, but it reality it's not -- at least not with GCC on OpenSuSE 10.3. Luc had turned key parts of these calls into macros and as a result he has experienced much greater performance. With this CS branch introducing a command submission infrastructure for R500 MMIO, this will allow for use of the GPU's CP (Command Processor) in a direct fashion without depending upon any Direct Rendering Manager.
For an end-user, this isn't something too exciting but ultimately should yield some interesting results.