On Thu, Jul 22, 2010 at 08:39:17AM +0100, Russell King - ARM Linux wrote:

On Wed, Jul 21, 2010 at 09:30:34PM -0700, Zach Pfeffer wrote:

quoted

This goes to the nub of the issue. We need a lot of 1 MB physically
contiguous chunks. The system is going to fragment and we'll never get
our 12 1 MB chunks that we'll need, since the DMA API allocator uses
the system pool it will never succeed.

By the "DMA API allocator" I assume you mean the coherent DMA interface,
The DMA coherent API and DMA streaming APIs are two separate sub-interfaces
of the DMA API and are not dependent on each other.

I didn't know that, but yes. As far as I can tell they both allocate
memory from the VM. We'd need a way to hook in our our own minimized
mapping allocator.