From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.free-electrons.com ([88.190.12.23]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QUeYi-0006VA-HP for linux-mtd@lists.infradead.org; Thu, 09 Jun 2011 12:42:01 +0000 Message-ID: <4DF0C03E.90909@free-electrons.com> Date: Thu, 09 Jun 2011 14:44:46 +0200 From: David Wagner MIME-Version: 1.0 To: dedekind1@gmail.com Subject: Re: impact of 2X_PROGRAM on read operations References: <4DECC41F.5060808@free-electrons.com> <1307370761.3112.76.camel@localhost> In-Reply-To: <1307370761.3112.76.camel@localhost> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org, kmpark@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 06/06/2011 04:32 PM, Artem Bityutskiy wrote: > On Mon, 2011-06-06 at 14:12 +0200, David Wagner wrote: >> Is there a way to safely read without 2X_PROGRAM enabled once it has >> been flashed with a 2X_PROGRAM-enabled flasher (e.g. patched u-boot). > > Not sure about u-boot, but AFAIK 2x is a completely separate mode which > gives you I/O speed-up but makes things incompatible with "normal" mode. > E.g., you can mount JFFS2 only in one of the modes. > Ok, so I guess it doesn't make sense trying to address the issue of incompatibilities. I may have to check once again, but I'm pretty sure, however, that I managed to flash a UBI image with a 2X_PROGRAM-enabled u-boot and read it with a regular kernel. The u-boot code for 2X_PROGRAM handling seems to basically be a copy-paste from the kernel. If the diagram in my first mail is correct, that could not be possible. Kyungmin, do you know what's wrong in my reasoning ? Regards, David Wagner. -- David Wagner, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com