On Thu, Aug 16, 2012 at 05:44:29PM -0400, Matt Porter wrote:

Add a DMA engine driver for the TI EDMA controller. This driver
is implemented as a wrapper around the existing DaVinci private
DMA implementation. This approach allows for incremental conversion
of each peripheral driver to the DMA engine API. The EDMA driver
supports slave transfers but does not yet support cyclic transfers.

Have you looked at the virt-dma support?  That should allow you to
avoid some common errors, like forgetting that stuff submitted but
not issued should not be started even if the channel is currently
running.