From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756166AbYDSF4x (ORCPT ); Sat, 19 Apr 2008 01:56:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751963AbYDSF4n (ORCPT ); Sat, 19 Apr 2008 01:56:43 -0400 Received: from www.tglx.de ([62.245.132.106]:51187 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751926AbYDSF4n (ORCPT ); Sat, 19 Apr 2008 01:56:43 -0400 Date: Sat, 19 Apr 2008 07:56:34 +0200 (CEST) From: Thomas Gleixner To: Alex Dubov cc: linux-kernel@vger.kernel.org, joern@logfs.org, ben@fluff.org Subject: Re: Smartmedia/xd card support - request for comments In-Reply-To: <51700.66276.qm@web36708.mail.mud.yahoo.com> Message-ID: References: <51700.66276.qm@web36708.mail.mud.yahoo.com> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 18 Apr 2008, Alex Dubov wrote: > mtd_blkdevs breaks the block layer request into separate pages, > effectively disabling lower layer from making decision based on a > real data block size, and using dma to any useful extent. What is > the proposed way to deal with this? Wrong in two aspects. 1) it does not break the request into separate pages. It breaks it into mtd_blktrans_ops->blksize chunks, which is set by the blkdev user. 2) Using DMA on raw NAND Flash is on per page basis except you have an "intellegent" controller chip which does the low level handling of the nand flash itself. Such controllers do not necessarily fit into MTD. > (By the way, first question already puts us into a "quirk" area of > the statement "smartmedia are flash chips with quirks". Both > memorystick and smartmedia are always operated in tandem with their > controllers, as you could notice.) I have no idea what you want to tell me. there is no quirk in a smartmedia card. Thanks, tglx