Re: [PATCH v7 05/14] crypto: marvell/CESA: add TDMA support

From: Boris Brezillon
Date: Wed Jun 17 2015 - 11:58:45 EST


On Wed, 17 Jun 2015 17:34:02 +0200
Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> wrote:

> On Wed, 17 Jun 2015 23:08:08 +0800
> Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
>
> > On Wed, Jun 17, 2015 at 03:32:02PM +0200, Boris Brezillon wrote:
> > >
> > > Hi Herbert,
> > >
> > > I send you this patch alone so that you can verify I'm now properly
> > > manipulating the SG list. Once I have your confirmation I'll send
> > > the whole series again and annoy all the people in Cc one more time
> > > ;-).
> >
> > Thanks. The only problem that I can see is the fact you're not
> > checking for req->src == req->dst. If they're equal then you must
> > not map it twice. Instead it should be mapped as DMA_BIDIRECTIONAL.
>
> I can check for that too, but note that it doesn't prevent one from
> providing different scatterlist structures pointing to the same memory
> region.

Actually, I don't know if it's a problem or not, so if it's not, please
ignore my comment.

> This being said, checking for req->src == req->dst should fix the case
> where dst and src are pointing to the same scatterlist, which is a good
> start.

Here is an incremental patch [1], please let me know if something else
is missing.

Thanks,

Boris

[1]http://code.bulix.org/x8mz8x-88568


--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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