From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 615BCCA9EA9 for ; Fri, 18 Oct 2019 16:22:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40D9E20869 for ; Fri, 18 Oct 2019 16:22:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436854AbfJRQWF (ORCPT ); Fri, 18 Oct 2019 12:22:05 -0400 Received: from [217.140.110.172] ([217.140.110.172]:45050 "EHLO foss.arm.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1727154AbfJRQWE (ORCPT ); Fri, 18 Oct 2019 12:22:04 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9EB30CA2; Fri, 18 Oct 2019 09:21:37 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E10B3F718; Fri, 18 Oct 2019 09:21:36 -0700 (PDT) Subject: Re: [PATCH 2/2] mfd: mfd-core: Honour Device Tree's request to disable a child-device To: Lee Jones , broonie@kernel.org, linus.walleij@linaro.org, daniel.thompson@linaro.org, arnd@arndb.de Cc: baohua@kernel.org, stephan@gerhold.net, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20191018122647.3849-1-lee.jones@linaro.org> <20191018122647.3849-3-lee.jones@linaro.org> From: Robin Murphy Message-ID: Date: Fri, 18 Oct 2019 17:21:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20191018122647.3849-3-lee.jones@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/10/2019 13:26, Lee Jones wrote: > Until now, MFD has assumed all child devices passed to it (via > mfd_cells) are to be registered. It does not take into account > requests from Device Tree and the like to disable child devices > on a per-platform basis. > > Well now it does. > > Reported-by: Barry Song > Reported-by: Stephan Gerhold > Signed-off-by: Lee Jones > --- > drivers/mfd/mfd-core.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c > index eafdadd58e8b..24c139633524 100644 > --- a/drivers/mfd/mfd-core.c > +++ b/drivers/mfd/mfd-core.c > @@ -182,6 +182,11 @@ static int mfd_add_device(struct device *parent, int id, > if (parent->of_node && cell->of_compatible) { > for_each_child_of_node(parent->of_node, np) { > if (of_device_is_compatible(np, cell->of_compatible)) { > + if (!of_device_is_available(np)) { > + /* Ignore disabled devices error free */ > + ret = 0; > + goto fail_alias; > + } Is it possible for a device to have multiple children of the same type? If so, it seems like this might not work as desired if, say, the first child was disabled but subsequent ones weren't. It might make sense to use for_each_available_child_of_node() for the outer loop, then check afterwards if anything was found. Robin. > pdev->dev.of_node = np; > pdev->dev.fwnode = &np->fwnode; > break; >