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=-11.1 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 C660BC4363A for ; Fri, 23 Oct 2020 14:16:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7997621527 for ; Fri, 23 Oct 2020 14:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750412AbgJWOQi (ORCPT ); Fri, 23 Oct 2020 10:16:38 -0400 Received: from smtp.radex.nl ([178.250.146.7]:59099 "EHLO radex-web.radex.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750404AbgJWOQh (ORCPT ); Fri, 23 Oct 2020 10:16:37 -0400 Received: from [192.168.1.158] (cust-178-250-146-69.breedbanddelft.nl [178.250.146.69]) by radex-web.radex.nl (Postfix) with ESMTPS id C9C9A24065; Fri, 23 Oct 2020 16:16:35 +0200 (CEST) From: Ferry Toth Subject: Re: [PATCH v1 2/2] device property: Don't clear secondary pointer for shared primary firmware node To: Heikki Krogerus , Andy Shevchenko Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Saravana Kannan , linux-acpi@vger.kernel.org, "Rafael J. Wysocki" References: <20201022184100.71659-1-andriy.shevchenko@linux.intel.com> <20201022184100.71659-2-andriy.shevchenko@linux.intel.com> <20201023123544.GB614478@kuha.fi.intel.com> Message-ID: <06eb930d-841f-29d9-e1e3-1f54d7bf10ca@gmail.com> Date: Fri, 23 Oct 2020 16:16:35 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201023123544.GB614478@kuha.fi.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Op 23-10-2020 om 14:35 schreef Heikki Krogerus: > On Thu, Oct 22, 2020 at 09:41:00PM +0300, Andy Shevchenko wrote: >> It appears that firmware nodes can be shared between devices. In such >> case >> when a (child) device is about to be deleted, its firmware node may >> be shared >> and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link >> of the shared primary firmware node. >> >> In order to prevent that, check, if the device has a parent and parent's >> firmware node is shared with its child, and avoid crashing the link. >> >> Fixes: c15e1bdda436 ("device property: Fix the secondary firmware >> node handling in set_primary_fwnode()") >> Reported-by: Ferry Toth >> Signed-off-by: Andy Shevchenko > FWIW: > > Reviewed-by: Heikki Krogerus Tested-by: Ferry Toth >> --- >> drivers/base/core.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/base/core.c b/drivers/base/core.c >> index 41feab679fa1..78114ddac755 100644 >> --- a/drivers/base/core.c >> +++ b/drivers/base/core.c >> @@ -4264,6 +4264,7 @@ static inline bool fwnode_is_primary(struct >> fwnode_handle *fwnode) >> */ >> void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode) >> { >> + struct device *parent = dev->parent; >> struct fwnode_handle *fn = dev->fwnode; >> if (fwnode) { >> @@ -4278,7 +4279,8 @@ void set_primary_fwnode(struct device *dev, >> struct fwnode_handle *fwnode) >> } else { >> if (fwnode_is_primary(fn)) { >> dev->fwnode = fn->secondary; >> - fn->secondary = ERR_PTR(-ENODEV); >> + if (!(parent && fn == parent->fwnode)) >> + fn->secondary = ERR_PTR(-ENODEV); >> } else { >> dev->fwnode = NULL; >> } >> -- 2.28.0