From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753741Ab2LDNWL (ORCPT ); Tue, 4 Dec 2012 08:22:11 -0500 Received: from bear.ext.ti.com ([192.94.94.41]:39607 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753708Ab2LDNWF (ORCPT ); Tue, 4 Dec 2012 08:22:05 -0500 From: "Philip, Avinash" To: "artem.bityutskiy@linux.intel.com" CC: "ivan.djelic@parrot.com" , "Mohammed, Afzal" , "linux-doc@vger.kernel.org" , "tony@atomide.com" , "gregkh@linuxfoundation.org" , "devicetree-discuss@lists.ozlabs.org" , "broonie@opensource.wolfsonmicro.com" , "Nori, Sekhar" , "linux-kernel@vger.kernel.org" , "Hebbar, Gururaja" , "linux-mtd@lists.infradead.org" , "rmk+kernel@arm.linux.org.uk" , "dwmw2@infradead.org" Subject: RE: [PATCH v2 0/3] mtd: nand: OMAP: ELM error correction support for BCH ecc Thread-Topic: [PATCH v2 0/3] mtd: nand: OMAP: ELM error correction support for BCH ecc Thread-Index: AQHNtzjAYJXEaMIpjk+PG7tWZP2/spfqfEcAgAaEjeCAAudd0IABibAAgABzjZCADDxHAIAGr3dw Date: Tue, 4 Dec 2012 13:20:50 +0000 Deferred-Delivery: Tue, 4 Dec 2012 13:20:00 +0000 Message-ID: <518397C60809E147AF5323E0420B992E3EA108CE@DBDE01.ent.ti.com> References: <1351667307-447-1-git-send-email-avinashphilip@ti.com> <1352978534.2221.33.camel@sauron.fi.intel.com> <518397C60809E147AF5323E0420B992E3E9EC70D@DBDE01.ent.ti.com> <1353581032.2701.34.camel@sauron.fi.intel.com> <518397C60809E147AF5323E0420B992E3E9EE329@DBDE01.ent.ti.com> <1354278498.30168.117.camel@sauron.fi.intel.com> In-Reply-To: <1354278498.30168.117.camel@sauron.fi.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.24.170.142] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id qB4DMJAV008886 On Fri, Nov 30, 2012 at 17:58:18, Artem Bityutskiy wrote: > On Thu, 2012-11-22 at 14:37 +0000, Philip, Avinash wrote: > > Idea here is to make faster scanning of erased page without bit flips. > > For omap nand driver ecc reported by hardware is non-zero and non > > 0xff. > > So comparing with the standard vector for erased page and skipping > > error > > correction for erased page without bit flips. > > So you mean that when you read a page, and you see there are bit-flips, > you start correcting them. But if you notice that the page is actually > an erased page, you optimize this case by not running the correction > machinery, but just filling the buffer with 0xFFs. Right? Yes it is an optimization for erased page bit flip handling. On erased page, ecc bytes not valid. So no direct correction machinery available for bit flips in erased page. Hence I was checking if any bit flips reported in erased page. If bit flip present in erased page and falls under correctable level, report the page with 0xff with correctable errors. Thanks Avinash > > > -- > Best Regards, > Artem Bityutskiy > {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I