Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751501AbdFHXVP (ORCPT ); Thu, 8 Jun 2017 19:21:15 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:36652 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751382AbdFHXVO (ORCPT ); Thu, 8 Jun 2017 19:21:14 -0400 Date: Thu, 8 Jun 2017 16:21:10 -0700 From: Brian Norris To: Boris Brezillon Cc: Chris Packham , dwmw2@infradead.org, andrew@lunn.ch, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Marek Vasut , Richard Weinberger , Cyrille Pitchen Subject: Re: [PATCH 3/4] mtd: mchp23k256: add partitioning support Message-ID: <20170608232110.GG102137@google.com> References: <20170517053908.26138-1-chris.packham@alliedtelesis.co.nz> <20170517053908.26138-4-chris.packham@alliedtelesis.co.nz> <20170517172911.5f926712@bbrezillon> <20170601184340.GA102137@google.com> <20170601224712.6a81a458@bbrezillon> <20170601220156.GD102137@google.com> <20170602110406.49eda282@bbrezillon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170602110406.49eda282@bbrezillon> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 681 Lines: 13 On Fri, Jun 02, 2017 at 11:04:06AM +0200, Boris Brezillon wrote: > BTW, MTD_NO_ERASE is not the only problem we have with UBI or JFFS2. > Are we guaranteed that an erase operation fills an eraseblock with > ones? Don't we have mem technologies that are filling them with zeros? > Note that mtdram is artificially setting the mem-region to 0xff in its > dummy erase operation, so maybe it's a implicit rule that ->_erase() is > supposed to fill eraseblocks with 0xff. I've wondered about the general assumption. But mtdram isn't really a good example, because it clearly calls itself a "test mtd device". So it makes sense it would emulate common MTDs (i.e., flash memory). Brian