Re: PCI DMA to small buffers on cache-incoherent arch

David S. Miller
2002-06-13T09:43:29Z

From: David Brownell <david-b@pacbell.net>
Date: Wed, 12 Jun 2002 22:13:17 -0700

David S. Miller wrote:
> We have two problems we want to solve, the DMA alignment stuff and
> using consistent memory for these small buffers. Therefore moving to
> consistent memory (by whatever mechanism the USB desires to implement
> this) is the way to go.

Right, the alignment stuff is a correctness issue, the consistent
memory issue is a performance concern. I like to think that 2.5
will have a lot less correctness issues in the USB stack, so it
can start to pay more attention to performance concerns.

I want to reemphasize that by going to consistent memory we solve
both problems, in particular the alignment stuff becomes a non-issue.