From mboxrd@z Thu Jan  1 00:00:00 1970
From: robherring2@gmail.com (Rob Herring)
Date: Fri, 08 Jul 2011 17:04:34 -0500
Subject: PL330 alignment requirement questions
In-Reply-To: <2034464824.379455.1310162217325.JavaMail.root@sz0140a.emeryville.ca.mail.comcast.net>
References: <2034464824.379455.1310162217325.JavaMail.root@sz0140a.emeryville.ca.mail.comcast.net>
Message-ID: <4E177EF2.9010900@gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 07/08/2011 04:56 PM, johnlinn at comcast.net wrote:
> I'm testing our PL330 with the driver/dma/pl330 driver and see some
> strangeness that's probably my own setup issue.
> 
> I'm also using drivers/dmatest to test it with memory to memory
> copies. I'm seeing that the copy alignment (copy_align) is not setup
> (it's 0) such that I see errors on some transfers at the end of the
> transfer.
> 
> If I setup the copy_align to be 3 or larger then I don't see these
> errors. This number doesn't make much sense to me and I'm digging
> into the details (seems like 4 would make sense).  I just wanted to
> see if anyone had tested with dmatest and seen anything similar.
> 
I ran this dmatest with Versatile Express and the example FPGA image
from ARM with the PL330 and also saw errors. You've narrowed it down
farther than I did and I don't have it setup currently.

Rob