From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [PATCH] ARM: OMAP3: gpmc: add BCH ecc api and modes Date: Wed, 25 Apr 2012 18:44:37 +0300 Message-ID: <1335368681.6356.16.camel@koala> References: <1334652536-4442-1-git-send-email-ivan.djelic@parrot.com> <1335365341.6356.5.camel@koala> <20120425152310.GR3739@atomide.com> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-+Mt5edcrmWCUlDGUCrIi" Return-path: Received: from mail-lb0-f174.google.com ([209.85.217.174]:59663 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752281Ab2DYPoo (ORCPT ); Wed, 25 Apr 2012 11:44:44 -0400 Received: by lbbgf7 with SMTP id gf7so203441lbb.19 for ; Wed, 25 Apr 2012 08:44:42 -0700 (PDT) In-Reply-To: <20120425152310.GR3739@atomide.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tony Lindgren Cc: linux-omap@vger.kernel.org, linux-mtd@lists.infradead.org, Ivan Djelic --=-+Mt5edcrmWCUlDGUCrIi Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2012-04-25 at 08:23 -0700, Tony Lindgren wrote: > Hi, >=20 > * Artem Bityutskiy [120425 07:52]: > > On Tue, 2012-04-17 at 10:48 +0200, Ivan Djelic wrote: > > > This patch adds a simple BCH ecc computation api, similar to the > > > existing Hamming ecc api. It is intended to be used by the MTD layer. > > > It implements the following features: > > >=20 > > > - support 4-bit and 8-bit ecc computation > > > - do not protect user bytes in spare area, only data area is protecte= d > > > - ecc for an erased NAND page (0xFFs) is also a sequence of 0xFFs > > >=20 > > > This last feature is obtained by adding a constant polynomial to > > > the hardware computed ecc. It allows to correct bitflips in blank pag= es > > > and is extremely useful to support filesystems such as UBIFS, which e= xpect > > > erased pages to contain only 0xFFs. > > >=20 > > > This api has been tested on an OMAP3630 board. > > >=20 > > > Signed-off-by: Ivan Djelic > >=20 > > Hi Tony, > >=20 > > what do you think about merging this patch? This is the enabler for > > making UBIFS actually usable on OMAP platforms which use BCH ECC. There > > are 2 other MTD patches which depend on this - so I wonder if it is > > easier to merge this one via the MTD tree, providing it has your/others= ' > > ack(s). >=20 > Looks OK to me, however there are other pending GPMC patches to convert > it to a platform device device driver. Need to look those closer though. > Anyways, it's best that I queue them to avoid merge conflicts. Sure. > Do you these for other changes for UBIFS? Not in UBIFS, but in drivers/mtd/nand/omap2.c - Ivan sent another patch which adds BCH support to to omap2.c, was sent to linux-omap, subject "[PATCH] mtd: nand: omap: add support for hardware BCH ecc" > If so, I can set up an immutable > branch for GPMC that you can merge in as well. I guess this would be a good idea, but probably it is better to do this when you believe you merged most gpmc patches, so probably closer to the final -rc? --=20 Best Regards, Artem Bityutskiy --=-+Mt5edcrmWCUlDGUCrIi 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 v1.4.11 (GNU/Linux) iQEcBAABAgAGBQJPmBvlAAoJEJtuLFy+q7fehPMIALBX8kO36EKXAld0t1ih1Pcs jEg0tyt+BN0HWpQYTfIqVnNcrw5BNtVOmmyxAM7bts0uTvNyEWhvKUyBJQFLbSLj iVUXsQwBIQLIl5bPj05mw+mVtsSST3m7C1kQtOs4bH2kyKCOQ7lkVWGmeG6/lz0E CvpqYJgptXcLxxcr6KjeIE2pFTnBaOz5mMoiuY9UAm/bgSDDpZhcXM+tONGWt8NO ffTdmA3BsDIMY4DJ8KrnJsQaJeM2HUagVUGzIn6dlpYO9lSpLqnclv4YsnL3zq4l 9UB2dT32EmLP/YJri5u6MS5PtgWNOAia9OwukvcXPZACrP+APVGdxEHjqKxqrM8= =bXgA -----END PGP SIGNATURE----- --=-+Mt5edcrmWCUlDGUCrIi--