From patchwork Tue Jan 5 09:11:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liao, Bard" X-Patchwork-Id: 357599 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 A2408C433E9 for ; Tue, 5 Jan 2021 09:13:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DD5D229CA for ; Tue, 5 Jan 2021 09:13:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727926AbhAEJNi (ORCPT ); Tue, 5 Jan 2021 04:13:38 -0500 Received: from mga17.intel.com ([192.55.52.151]:50274 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727922AbhAEJNh (ORCPT ); Tue, 5 Jan 2021 04:13:37 -0500 IronPort-SDR: aFYyTwkkOO51OzhiK9CXy4FsjM4rmXkqDabpuIHL0OILHRtiU2dY1/wHrHZpftN70r1mu/r8Ub IYD7g0sU2NsQ== X-IronPort-AV: E=McAfee;i="6000,8403,9854"; a="156862078" X-IronPort-AV: E=Sophos;i="5.78,476,1599548400"; d="scan'208";a="156862078" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2021 01:11:51 -0800 IronPort-SDR: VVhF95p9st5xLBTXdLZ6yja8BVMHiBlCOm/ZMHGL6AmvzZXwA4+G3hwSiRE1uoUxK+B8JXqBOA jypsA8TDu8mQ== X-IronPort-AV: E=Sophos;i="5.78,476,1599548400"; d="scan'208";a="378794974" Received: from bard-ubuntu.sh.intel.com ([10.239.13.33]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2021 01:11:49 -0800 From: Bard Liao To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, andriy.shevchenko@linux.intel.com, linux-acpi@vger.kernel.org, heikki.krogerus@linux.intel.com, rafael@kernel.org Cc: bard.liao@intel.com Subject: [PATCH 2/2] device property: add description of fwnode cases Date: Tue, 5 Jan 2021 17:11:46 +0800 Message-Id: <20210105091146.25422-3-yung-chuan.liao@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210105091146.25422-1-yung-chuan.liao@linux.intel.com> References: <20210105091146.25422-1-yung-chuan.liao@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org There are only four valid fwnode cases which are - primary --> secondary --> -ENODEV - primary --> NULL - secondary --> -ENODEV - NULL dev->fwnode should be converted between the 4 cases above no matter how/when set_primary_fwnode() and set_secondary_fwnode() are called. Describe it in the code so people will keep it in mind. Signed-off-by: Bard Liao Reviewed-by: Heikki Krogerus --- drivers/base/core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 51b9545a050b..17eb14607074 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -4414,6 +4414,12 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode) * * Set the device's firmware node pointer to @fwnode, but if a secondary * firmware node of the device is present, preserve it. + * + * Valid fwnode cases are: + * - primary --> secondary --> -ENODEV + * - primary --> NULL + * - secondary --> -ENODEV + * - NULL */ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode) { @@ -4432,6 +4438,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode) } else { if (fwnode_is_primary(fn)) { dev->fwnode = fn->secondary; + /* Set fn->secondary = NULL to keep fn as a primary fwnode */ if (!(parent && fn == parent->fwnode)) fn->secondary = NULL; } else {