Phoronix: Radeon 3.8 DRM Picks Up Last Round Of Features
While there was already one round of driver changes for the AMD Radeon DRM kernel driver to be found in the Linux 3.8 kernel, followed by a second pull days later that landed a-synchronous DMA engine support, there's now a third set of changes targeting the Radeon driver in this next kernel release...
Michael, you missed a rather important fact here: The pull request also contains the code for the CP-DMA command submission checker, that is the DMA engine controlled by the command processor (the execution unit that is responsible for GFX and compute jobs).
So this is the stuff necessary to use the synchronous DMA engine. With it we should now have all available DMA engines (synchronous and asynchronous) public and an additional major bit of the Radeon hardware documented.