From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Fri, 28 Mar 2014 10:01:58 +0100
From: Lothar =?UTF-8?B?V2HDn21hbm4=?= <LW@KARO-electronics.de>
To: Huang Shijie <b32955@freescale.com>
Subject: Re: [PATCHv2 1/1] mtd: gpmi: make blockmark swapping optional
Message-ID: <20140328100158.042a3d68@ipc1.ka-ro>
In-Reply-To: <53353524.9020605@freescale.com>
References: <532BCFCC.4080205@freescale.com>
 <1395399017-19005-1-git-send-email-LW@KARO-electronics.de>
 <20140324095902.GB11377@localhost>
 <20140326095156.3e5585b8@ipc1.ka-ro>
 <5332AEE7.2040402@freescale.com>
 <20140326125502.0e8d0657@ipc1.ka-ro>
 <20140327095956.GA29623@localhost>
 <20140327132109.06258526@ipc1.ka-ro>
 <5334D9F7.2030001@freescale.com>
 <20140328091646.1ce03f90@ipc1.ka-ro>
 <53353524.9020605@freescale.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Cc: Fabio Estevam <fabio.estevam@freescale.com>,
 Mark Rutland <mark.rutland@arm.com>, Shawn Guo <shawn.guo@linaro.org>,
 Russell King <linux@arm.linux.org.uk>, Pawel Moll <pawel.moll@arm.com>,
 Arnd Bergmann <arnd@arndb.de>, Ian Campbell <ijc+devicetree@hellion.org.uk>,
 Artem Bityutskiy <artem.bityutskiy@linux.intel.com>, linux-doc@vger.kernel.org,
 linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
 Rob Herring <robh+dt@kernel.org>, linux-mtd@lists.infradead.org,
 linux-arm-kernel@lists.infradead.org, Rob Landley <rob@landley.net>,
 Kumar Gala <galak@codeaurora.org>, Brian Norris <computersforpeace@gmail.com>,
 David Woodhouse <dwmw2@infradead.org>, Sascha Hauer <kernel@pengutronix.de>,
 Shawn Guo <shawn.guo@freescale.com>
List-Id: Linux MTD discussion mailing list <linux-mtd.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/linux-mtd/>
List-Post: <mailto:linux-mtd@lists.infradead.org>
List-Help: <mailto:linux-mtd-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=subscribe>

Hi,

Huang Shijie wrote:
> =E4=BA=8E 2014=E5=B9=B403=E6=9C=8828=E6=97=A5 16:16, Lothar Wa=C3=9Fmann =
=E5=86=99=E9=81=93:
> > Still there is no need for the Linux NAND driver to be able to read or
> > write partitions in a format that the Boot ROM can understand. Thus it
> If you do not use the NAND boot, there really no need to do so.
>
There is no need for the ROM code to access any other partition than
the bootloader itself. Thus Linux can perfectly well be booted from
NAND without any byte swapping.

> Since you need the NAND boot, we should enable the swapping for imx28.
>
Why? There is no need for Linux to do any swapping when not accessing
the bootloader partition.

> > is perfectly legal to allow disregarding the BB marks and solely rely on
> > a flash based BBT.
> >
> The BB mark is in the page 0 of a NAND block. But the swapping can occur=
=20
> in _each_ page of
> a NAND block, _NOT_ only the page 0.
>=20
> I think you are confusing at these two things.
>=20
No, I'm not confusing anything. The swapping in any other page than
page 0 is completely useless. Thus, when there is no need to recognize
the BB markers, there in no need to do any swapping too.


Lothar Wa=C3=9Fmann
--=20
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstra=C3=9Fe 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Gesch=C3=A4ftsf=C3=BChrer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info@karo-electronics.de
___________________________________________________________