On Thu, Aug 14, 2003 at 02:52:07PM -0700, cgd@broadcom.com wrote:
> Note that those are choices for a particular implementation.  There
> are many implementations for which BUS_DMA_COHERENT should be
> cacheable, as well.

After some offline discussion with Nathan, I think I'm agreeing
with you.  I would still want to have something that does mean
totally "raw" (uncached, coherent, not bufferred) as well--for
debugging uses and for other situations where you may just really
want totally uncached access.

For this to work, though, we would (as you note) have to define
COHERENT as a required part of the interface, and I'd add a
BUS_DMA_NOCACHE (or BUS_DMA_RAW or whatever makes sense).

Does that make more sense?

-allen

-- 
 Allen Briggs                     briggs@wasabisystems.com
 Wasabi Systems, Inc.             http://www.wasabisystems.com/