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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 2CEF0C38A2C for ; Fri, 17 Apr 2020 16:55:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F04F122202 for ; Fri, 17 Apr 2020 16:55:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727913AbgDQQzA (ORCPT ); Fri, 17 Apr 2020 12:55:00 -0400 Received: from mx2.suse.de ([195.135.220.15]:42424 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727840AbgDQQy6 (ORCPT ); Fri, 17 Apr 2020 12:54:58 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 06275AE21; Fri, 17 Apr 2020 16:54:55 +0000 (UTC) From: Nicolas Saenz Julienne To: saravanak@google.com, linux-kernel@vger.kernel.org, Rob Herring , Frank Rowand , Greg Kroah-Hartman Cc: devicetree@vger.kernel.org, Nicolas Saenz Julienne Subject: [PATCH v2 2/2] of: property: Do not link to disabled devices Date: Fri, 17 Apr 2020 18:54:42 +0200 Message-Id: <20200417165442.1856-3-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200417165442.1856-1-nsaenzjulienne@suse.de> References: <20200417165442.1856-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When creating a consumer/supplier relationship between two devices, make sure the supplier node is actually active. Otherwise this will create a link relationship that will never be fulfilled. This, in the worst case scenario, will hang the system during boot. Note that, in practice, the fact that a device-tree represented consumer/supplier relationship isn't fulfilled will not prevent devices from successfully probing. Fixes: a3e1d1a7f5fc ("of: property: Add functional dependency link from DT bindings") Signed-off-by: Nicolas Saenz Julienne --- Changes since v1: - Move availability check into the compatible search routine and bail if device node disabled drivers/of/property.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/of/property.c b/drivers/of/property.c index dc034eb45defd..14b6266dd054b 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1045,8 +1045,25 @@ static int of_link_to_phandle(struct device *dev, struct device_node *sup_np, * Find the device node that contains the supplier phandle. It may be * @sup_np or it may be an ancestor of @sup_np. */ - while (sup_np && !of_find_property(sup_np, "compatible", NULL)) + while (sup_np) { + + /* + * Don't allow linking a device node as consumer of a disabled + * node. + */ + if (!of_device_is_available(sup_np)) { + dev_dbg(dev, "Not linking to %pOFP - Not available\n", + sup_np); + of_node_put(sup_np); + return -ENODEV; + } + + if (of_find_property(sup_np, "compatible", NULL)) + break; + sup_np = of_get_next_parent(sup_np); + } + if (!sup_np) { dev_dbg(dev, "Not linking to %pOFP - No device\n", tmp_np); return -ENODEV; -- 2.26.0