Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030894AbbD1OET (ORCPT ); Tue, 28 Apr 2015 10:04:19 -0400 Received: from skprod3.natinst.com ([130.164.80.24]:44883 "EHLO ni.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965832AbbD1OER (ORCPT ); Tue, 28 Apr 2015 10:04:17 -0400 Date: Tue, 28 Apr 2015 09:03:47 -0500 From: Josh Cartwright To: punnaiah choudary kalluri Cc: Brian Norris , Richard Weinberger , Ben Shelton , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" , David Woodhouse , Punnaiah Choudary Kalluri , Boris Brezillon Subject: Re: [PATCH 1/3] mtd: nand: Add on-die ECC support Message-ID: <20150428140347.GC2798@jcartwri.amer.corp.natinst.com> References: <1427292151-3835-1-git-send-email-richard@nod.at> <1427292151-3835-2-git-send-email-richard@nod.at> <20150427213558.GA22780@bshelton-desktop> <553EB5E4.3050309@nod.at> <20150427232353.GD32500@ld-irv-0074> <20150428032213.GI19571@brian-ubuntu> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-MIMETrack: Itemize by SMTP Server on US-AUS-MGWOut1/AUS/H/NIC(Release 8.5.3FP6|November 21, 2013) at 04/28/2015 09:03:47 AM, Serialize by Router on US-AUS-MGWOut1/AUS/H/NIC(Release 8.5.3FP6|November 21, 2013) at 04/28/2015 09:03:47 AM, Serialize complete at 04/28/2015 09:03:47 AM Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="B4IIlcmfBL/1gGOG" Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2015-04-28_05:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2368 Lines: 62 --B4IIlcmfBL/1gGOG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 28, 2015 at 09:14:26AM +0530, punnaiah choudary kalluri wrote: > On Tue, Apr 28, 2015 at 8:52 AM, Brian Norris wrote: > > On Tue, Apr 28, 2015 at 08:18:12AM +0530, punnaiah choudary kalluri wro= te: > >> On Tue, Apr 28, 2015 at 4:53 AM, Brian Norris wrote: [..] > >> Agree that read_buf need not be returning raw data always including > >> my new driver for arasan nand flash controller. > > > > I agree with that. At the moment, chip->read_buf() really has very > > driver-specific meaning. Not sure if that's really a good thing, but > > it's the way things are... > > > >> http://lkml.iu.edu/hypermail/linux/kernel/1504.2/00313.html > > > > In the half a minute I just spent looking at this (I may review it > > properly later), I noted a few things: > > > > 1. you don't implement ecc.read_page_raw(); this means we'll probably > > have trouble supporting on-die ECC with your driver, among other things >=20 > On-die ECC is optional as long as the controller has better ecc coverage. > The arasan controller supports up to 24 bit ecc. There is no point to use > on-die ECC and will always use hw ecc even for On-die ecc devices. Maybe this is true of the controller instantiated in the Zynq MPSoC chips, but the Zynq 7000 series SMC is documented to support only 1-bit ECC. (Which is why we're looking at your pl353 driver and this set). Josh --B4IIlcmfBL/1gGOG Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAABCAAGBQJVP5M/AAoJEKp7ZBKwQFArIKEH/0hmA21KwBjUnbtnD7FsisjE gHNWB6Zlthj14lrSMgVv6nKPnB7+InYHn4y6B4eNYOE6urQfP9kVSoN87WDilW2G yzdVesiS93Mkha7e0Ix9Cyg1G021ndM+X/Yaq903O0RCbzmBVOmxkVeLr7gbO1vS 8ywJ1Hw1LceicKRopkOJwfjI63Tk9FmgDWiWpD3/D2wO+ImIq7CgzkrtNKavb0HY SYZf95jWJZIL419PrbjDlSvIX5LJ646XIuFulUBZJ8xE8qeNjmNhtxj7Mp/8PxFS yT1p11XV5GxqebyQWOHy1agRWhuI3+qWME8FoOY2/pO7apcSxEgiOqPGSs2FMOg= =v0qL -----END PGP SIGNATURE----- --B4IIlcmfBL/1gGOG-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/