From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831Ab0IBLmo (ORCPT ); Thu, 2 Sep 2010 07:42:44 -0400 Received: from www84.your-server.de ([213.133.104.84]:41864 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751147Ab0IBLmn (ORCPT ); Thu, 2 Sep 2010 07:42:43 -0400 Subject: Re: [PATCH] Add quick erase format option From: Stefani Seibold To: dedekind1@gmail.com Cc: David Woodhouse , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , Artem Bityutskiy , "linux-mtd@lists.infradead.org" , "Enzinger, Robert (EXT-Other - DE/Munich)" In-Reply-To: <1283425100.3085.5.camel@brekeke> References: <1281342353-18180-1-git-send-email-stefani@seibold.net> <1281343038.12908.25.camel@localhost> <1281343974.18398.13.camel@wall-e.seibold.net> <1281353344.2332.8.camel@brekeke> <1281362069.20181.16.camel@wall-e.seibold.net> <1283081435.2131.24.camel@brekeke> <1283236978.6083.28.camel@wall-e.seibold.net> <1283302043.2018.92.camel@brekeke> <1283410392.6920.36.camel@wall-e.seibold.net> <1283425100.3085.5.camel@brekeke> Content-Type: text/plain; charset="ISO-8859-15" Date: Thu, 02 Sep 2010 13:42:43 +0200 Message-ID: <1283427763.9613.0.camel@wall-e.seibold.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.2 Content-Transfer-Encoding: 7bit X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Donnerstag, den 02.09.2010, 13:58 +0300 schrieb Artem Bityutskiy: > On Thu, 2010-09-02 at 08:53 +0200, Stefani Seibold wrote: > > --do-not-use-me is the best. But more seriously i think we should it > > split it into two options. --all-erased and --check-erased. The first > > assumes that all PEB are erased, while the second do the check if the > > PEB is erased and if not it will be erased. > > > > So we can handle NAND's, which have a fast erase, and NOR's which are > > very slow. With this we are able to pick the best option for the > > manufacturing. > > I am fine with checking, but what bothers me is that you check only 64 > bytes out of 128KiB - why this is enough to make sure the eraseblock is > erased? > > Probably it is ok for you, but in for general use-case this is wrong, > even checking all 128KiB is wrong, because of the unstable bits. > > What I think will make more sense is to add general option --verify or > something like that. It would read everything the utility wrote and > verify it is identical to what was written. Probably this can be done in > libmtd. > > Then you will be able to combine --all-erased with --verify and achieve > what you want. > Agree. I will create a patch for this in the next few days. - Stefani