From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932182Ab1BWJhj (ORCPT ); Wed, 23 Feb 2011 04:37:39 -0500 Received: from mail-bw0-f51.google.com ([209.85.214.51]:33161 "EHLO mail-bw0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755049Ab1BWJhh (ORCPT ); Wed, 23 Feb 2011 04:37:37 -0500 Message-ID: <4D64D55B.50405@monstr.eu> Date: Wed, 23 Feb 2011 10:37:31 +0100 From: Michal Simek Reply-To: monstr@monstr.eu User-Agent: Thunderbird 2.0.0.22 (X11/20090625) MIME-Version: 1.0 To: Arnd Bergmann CC: devicetree-discuss@lists.ozlabs.org, Grant Likely , linux-i2c@vger.kernel.org, john.williams@petalogix.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] i2c: xiic: Use 32bit accesses only References: <1298396971-611-1-git-send-email-monstr@monstr.eu> <4D64C08F.5030604@monstr.eu> <201102230936.09921.arnd@arndb.de> In-Reply-To: <201102230936.09921.arnd@arndb.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Arnd Bergmann wrote: > On Wednesday 23 February 2011 09:08:47 Michal Simek wrote: >> Grant Likely wrote: >>> On Tue, Feb 22, 2011 at 10:49 AM, Michal Simek wrote: >>>> i2c driver is used for LE/BE that's why is useful to use >>>> 32bit accesses. Then it is not necessary to solve any >>>> endian issues. >>> Are you sure? I would expect the BE version needs to use >>> io{read,write}32be variants of the accessors. What platforms have you >>> tested on? >> iowrite32 is the same with iowrite32be for Microblaze. >> I have no problem to change it to iowrite32be if you like. >> >> I have tested it on microblaze big and little endian platforms. > > I think what Grant was saying is that iowrite32 being the same as > iowrite32be is a bug, because iowrite32 is documented to be little-endian. Can you pointed me to that documentation? > > This is probably fine as long as you don't have any PCI devices, > but if you ever get PCI support, it won't work. Microblaze have PCI support but I don't have the board for testing. > > Also, it heavily confuses other developers such as Grant and me > if one architecture defines things to mean something completely > different from the other architectures. As I see will be good to review microblaze io.h and use generic one. Thanks, Michal -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/ Microblaze U-BOOT custodian