From: Dan Williams <dan.j.williams@intel.com>
To: "Ira W. Snyder" <iws@ovro.caltech.edu>
Cc: "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFCv1 1/2] dmaengine: add support for scatterlist to scatterlist transfers
Date: Fri, 24 Sep 2010 15:20:14 -0700 [thread overview]
Message-ID: <1285366814.21375.30.camel@dwillia2-linux> (raw)
In-Reply-To: <20100924220419.GC24654@ovro.caltech.edu>
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
next prev parent reply other threads:[~2010-09-24 22:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-24 19:46 [PATCH RFCv1 0/2] dma: add support for sg-to-sg transfers Ira W. Snyder
2010-09-24 19:46 ` [PATCH RFCv1 1/2] dmaengine: add support for scatterlist to scatterlist transfers Ira W. Snyder
2010-09-24 20:40 ` Dan Williams
2010-09-24 20:40 ` Dan Williams
2010-09-24 21:24 ` Ira W. Snyder
2010-09-24 21:24 ` Ira W. Snyder
2010-09-24 21:53 ` Dan Williams
2010-09-24 21:53 ` Dan Williams
2010-09-24 22:04 ` Ira W. Snyder
2010-09-24 22:20 ` Dan Williams [this message]
2010-09-24 22:53 ` Ira W. Snyder
2010-09-24 19:46 ` [PATCH RFCv1 2/2] fsldma: use generic " Ira W. Snyder
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1285366814.21375.30.camel@dwillia2-linux \
--to=dan.j.williams@intel.com \
--cc=iws@ovro.caltech.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.