From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [PATCH] omap : nand : fix subpage ecc issue with prefetch Date: Fri, 06 May 2011 21:56:17 +0300 Message-ID: <1304708177.7222.101.camel@localhost> References: <1304334638-2198-1-git-send-email-kishore.kadiyala@ti.com> <1304621338.7222.55.camel@localhost> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-ey0-f174.google.com ([209.85.215.174]:55241 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932502Ab1EFS7t (ORCPT ); Fri, 6 May 2011 14:59:49 -0400 Received: by eyx24 with SMTP id 24so1060312eyx.19 for ; Fri, 06 May 2011 11:59:48 -0700 (PDT) In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Vimal Singh Cc: Kishore Kadiyala , linux-omap@vger.kernel.org, linux-mtd@lists.infradead.org, bdefaria@adeneo-embedded.com On Fri, 2011-05-06 at 13:00 +0530, Vimal Singh wrote: > On Fri, May 6, 2011 at 12:18 AM, Artem Bityutskiy wrote: > > On Mon, 2011-05-02 at 16:40 +0530, Kishore Kadiyala wrote: > >> For prefetch engine, read and write got broken in commit '2c01946= c'. > >> We never hit a scenario of not getting 'gpmc_prefetch_enable' > >> call success. > >> When reading/writing a subpage with a non divisible by 4 ecc numbe= r > >> of bytes, the mis-aligned bytes gets handled first before enabling > >> the Prefetch engine, then it reads/writes rest of the bytes. > >> > >> Signed-off-by: Kishore Kadiyala > >> Signed-off-by: Vimal Singh > >> Reported-by: Bryan DE FARIA > > > > This needs a better commit message with more explanation and analys= is of > > the problem and how it was fixed.This commit message is not very > > understandable. And then it needs also: >=20 > How about a commit log like this: Looks better, thanks. Waiting for the new patch. >=20 > When reading/writing a subpage (When HW ECC is not available/enable) > for number of bytes not aligned to 4, the mis-aligned bytes gets > handled first (by cpu copy mathod) before enabling the Prefetch > engin to/from 'p' (start of buffer 'buf'). > Then it reads/writes rest of the bytes with the help of Prefetch > engine, if available, or again by cpu copy mathod. Currnetly, > reading/writing of rest of bytes, is not done correctly. Its trying t= o > read/write again to/from begining of buffer 'buf', overwriting the > mis-aligned bytes. >=20 > For prefetch engine read and write it got broken in commit '2c01946c'= =2E > And we never hit the scenario of not getting 'gpmc_prefetch_enable' > call sucess. So, problem did not get caught up. >=20 > This patch fixes the issue. --=20 Best Regards, Artem Bityutskiy (=D0=90=D1=80=D1=82=D1=91=D0=BC =D0=91=D0=B8=D1=82=D1=8E= =D1=86=D0=BA=D0=B8=D0=B9) -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html