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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 12B8DC55179 for ; Fri, 23 Oct 2020 12:35:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C059D2463C for ; Fri, 23 Oct 2020 12:35:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S463859AbgJWMfw (ORCPT ); Fri, 23 Oct 2020 08:35:52 -0400 Received: from mga09.intel.com ([134.134.136.24]:50491 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S373078AbgJWMfv (ORCPT ); Fri, 23 Oct 2020 08:35:51 -0400 IronPort-SDR: 7BNfCakLMaEFZGcEC5Yf4najxrgrYw35gNWEi90LdH5zCqNyScSHccZuQa6PfelIkZqERYuIkD XD9qo1W2t5Xg== X-IronPort-AV: E=McAfee;i="6000,8403,9782"; a="167789278" X-IronPort-AV: E=Sophos;i="5.77,408,1596524400"; d="scan'208";a="167789278" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Oct 2020 05:35:48 -0700 IronPort-SDR: yX3P1NLute2OCFJbEoV2QgCeJ3Khe2GYWQ1s2O/XgWeGaIkBy0U6njMb8AAT2MWShOKKjD80aN 4NWoOOjn9brw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,408,1596524400"; d="scan'208";a="423415808" Received: from kuha.fi.intel.com ([10.237.72.162]) by fmsmga001.fm.intel.com with SMTP; 23 Oct 2020 05:35:45 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Fri, 23 Oct 2020 15:35:44 +0300 Date: Fri, 23 Oct 2020 15:35:44 +0300 From: Heikki Krogerus To: Andy Shevchenko Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Saravana Kannan , linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , Ferry Toth Subject: Re: [PATCH v1 2/2] device property: Don't clear secondary pointer for shared primary firmware node Message-ID: <20201023123544.GB614478@kuha.fi.intel.com> References: <20201022184100.71659-1-andriy.shevchenko@linux.intel.com> <20201022184100.71659-2-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201022184100.71659-2-andriy.shevchenko@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org 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 > --- > 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 -- heikki