[PATCH RFCv1 1/2] dmaengine: add support for scatterlist to scatterlist transfers

Dan Williams dan.j.williams at intel.com
Sat Sep 25 08:20:14 EST 2010


On Fri, 2010-09-24 at 15:04 -0700, Ira W. Snyder wrote:
> On Fri, Sep 24, 2010 at 02:53:14PM -0700, Dan Williams wrote:
> > What about overrun or underrun do we not care if src_total != dst_total?
> > 
> > Otherwise looks ok.
> > 
> 
> I don't know if we should care about that. The algorithm handles that
> case just fine. It copies the maximum amount it can, which is exactly
> min(src_total, dst_total). Whichever scatterlist runs out of entries
> first is the shortest.
> 
> As a real world example, my driver verifies that both scatterlists have
> exactly the right number of bytes available before trying to program the
> hardware.

Ok, just handle the prep failure and I think we are good to go.

--
Dan




More information about the Linuxppc-dev mailing list