From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [PATCH] mtd: omap2-nand: avoid unaligned DMA accesses, fall back on prefetch method Date: Fri, 28 Sep 2012 06:35:45 +0300 Message-ID: <1348803345.1830.2.camel@kyv> References: <1348155850-26174-1-git-send-email-arnout@mind.be> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-PeYRArTOnmsCKx5t8CSp" Return-path: Received: from mail-la0-f46.google.com ([209.85.215.46]:55187 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755352Ab2I1DgG (ORCPT ); Thu, 27 Sep 2012 23:36:06 -0400 Received: by lagh6 with SMTP id h6so781736lag.19 for ; Thu, 27 Sep 2012 20:36:04 -0700 (PDT) In-Reply-To: <1348155850-26174-1-git-send-email-arnout@mind.be> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Arnout Vandecappelle (Essensium/Mind)" Cc: linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org, David Woodhouse , Tony Lindgren , Sven Krauss --=-PeYRArTOnmsCKx5t8CSp Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2012-09-20 at 17:44 +0200, Arnout Vandecappelle (Essensium/Mind) wrote: > It's difficult to reproduce the error, because the buffers are > aligned most of the time. Can you just take one of the mtd tests (e.g., mtd_speedtest), amend it a little and make sure it uses unaligned buffers? > Perhaps a better method is to fetch the first few unaligned bytes > with the prefetch method, and then continue with DMA. However, > since it's hard to force an unaligned buffer, it's also hard to > test that this method works. Yes, this would be a lot cleaner. --=20 Best Regards, Artem Bityutskiy --=-PeYRArTOnmsCKx5t8CSp Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAABAgAGBQJQZRsRAAoJECmIfjd9wqK0WukP/16ei9hMSBIum7Tn4z+BOSYM 4sak8j58lqy8JIl3VA8/Pgvj3guVWCF8vexBvCpcELmtVia7UsGWLdNlCpGT4sAI lATz5rqyytiEoPvwjDTL0WxFZo0tgvPQ44NoDtbyOMHxgPj6/NzqAMlHyG2QQDJA JCsV7lxqa73TY7aL9NvCHxkyUKx7CgP+zwpqghdTl8Z1c/MBGmWyPr9Do/jyUuCC ugQBsKWta41jZbW1VYas9HrtvsMJSV71pt5WpYaRDH+5EVOxrlxu2DCxFvakFBNV f5tdDhFULRIwhtgMRmEW0RHP47PbTcmEaEFB6MgvJr/r6SjpMqIhvrbsx16kj6h8 Fm6a5fUw5lJzL/Bo9BKNNskEhbq7zPFIcw1H9Dqd9zmXtEkoQx52RkcDgFLfZzAm WNoCmUvWEWTN6C4sjt6aCrmTkPRkWJp2sf32WWl+WfjJIBUmfTsiS3B7DKqGqdOJ 07LWT6wpE4NG/5PcrHaHHmxNW1ev0nbyx+moNHSAtI5e5msv59WkAlVlF9BI9Tvx dltIHhKWt2pcP6ijmkq90YR7xq6A4GDqB68UyWuk/4LXBVHu0/5biCrv/JiHDXTd n4qM+KDdPJKXzv4JRyS7l87Tp7Sd8J5ZFQizNnzvouUFpYzdN3iDVatFH1orgZc0 BbYK/HDrHn1sg8DcT6W4 =LXSN -----END PGP SIGNATURE----- --=-PeYRArTOnmsCKx5t8CSp--