From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933773AbXCZJqS (ORCPT ); Mon, 26 Mar 2007 05:46:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933775AbXCZJqS (ORCPT ); Mon, 26 Mar 2007 05:46:18 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:55531 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933773AbXCZJqR (ORCPT ); Mon, 26 Mar 2007 05:46:17 -0400 Subject: Re: [PATCH 00/22 take 3] UBI: Unsorted Block Images From: David Woodhouse To: =?ISO-8859-1?Q?J=F6rn?= Engel Cc: David Lang , Thomas Gleixner , Matt Mackall , Josh Boyer , Artem Bityutskiy , Linux Kernel Mailing List , Frank Haverkamp , Christoph Hellwig In-Reply-To: <20070326010443.GF19691@lazybastard.org> References: <20070319223205.GZ4892@waste.org> <1174351366.13341.739.camel@localhost.localdomain> <20070321110528.GC3785@lazybastard.org> <1174476334.10840.49.camel@localhost.localdomain> <20070325200826.GA19691@lazybastard.org> <20070325225528.GD19691@lazybastard.org> <1174866394.2866.2.camel@shinybook.infradead.org> <20070326000149.GE19691@lazybastard.org> <1174868485.20505.284.camel@pmac.infradead.org> <20070326010443.GF19691@lazybastard.org> Content-Type: text/plain; charset=UTF-8 Date: Mon, 26 Mar 2007 10:45:57 +0100 Message-Id: <1174902357.20505.292.camel@pmac.infradead.org> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 (2.8.3-1.fc6.dwmw2.1) Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2007-03-26 at 03:04 +0200, Jörn Engel wrote: > That limitation stems from ECC and ECC is done in software. Currently > everyone and his dog is doing ECC in chunks of 256 bytes on NAND. So > your minimum write size is 256 bytes _if you care about ECC_. If you > don't care, you can write single bits on NAND, just as you can on NOR. No, on NAND flash it's a limitation of the hardware. The number of write cycles you can perform to a given page is limited. Exceed it and the contents of that page become undefined due to leakage, until you next erase it. -- dwmw2