From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932784Ab2GCNHv (ORCPT ); Tue, 3 Jul 2012 09:07:51 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:39187 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752252Ab2GCNHu (ORCPT ); Tue, 3 Jul 2012 09:07:50 -0400 Message-ID: <4FF2EEA1.6080204@linaro.org> Date: Tue, 03 Jul 2012 14:07:45 +0100 From: Lee Jones User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: Mark Brown CC: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linus.walleij@stericsson.com, arnd@arndb.de, sameo@linux.intel.com Subject: Re: [PATCH 1/1] mfd: Fix runtime warning caused by duplicate device registration References: <1341316788-12730-1-git-send-email-lee.jones@linaro.org> <20120703123552.GC25995@sirena.org.uk> In-Reply-To: <20120703123552.GC25995@sirena.org.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/07/12 13:35, Mark Brown wrote: > On Tue, Jul 03, 2012 at 12:59:48PM +0100, Lee Jones wrote: >> We register the ab8500 as an MFD device from db8500 code during Device Tree >> boot in order to solve some limitations of DT. However, when Device Tree is >> not enabled, we still want to allow platform code to register the ab8500 in >> the normal way. Here we force MFD device registration of the ab8500 only >> when booting with Device Tree enabled. >> >> Solves this issue: >> WARNING: at fs/sysfs/dir.c:526 sysfs_add_one+0x88/0xb0() >> sysfs: cannot create duplicate filename '/bus/platform/devices/ab8500-core.0' > > Do we really want to create MFD cells like this (which are really Linux > internal things and might vary if another OS or another version of Linux > changes its internal abstractions) from the device tree? We're not creating them. We're merely using current infrastructure. Before, when we probed each device from Device Tree we came up against some fairly major limitations of the Device Tree. As a result, Arnd and I agreed that this was the way to go. See c5395e7ed8f16cc7bb72a783de68659db5aed515 for a short description of the troubles we faced. -- Lee Jones Linaro ST-Ericsson Landing Team Lead M: +44 77 88 633 515 Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog