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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 2B11FC2BA19 for ; Wed, 15 Apr 2020 15:06:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0713020857 for ; Wed, 15 Apr 2020 15:06:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S371202AbgDOPG2 (ORCPT ); Wed, 15 Apr 2020 11:06:28 -0400 Received: from mx2.suse.de ([195.135.220.15]:60700 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394091AbgDOPGU (ORCPT ); Wed, 15 Apr 2020 11:06:20 -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 E4142AFBE; Wed, 15 Apr 2020 15:06:17 +0000 (UTC) From: Nicolas Saenz Julienne To: saravanak@google.com, Greg Kroah-Hartman , devicetree@vger.kernel.org, Rob Herring , Frank Rowand Cc: Nicolas Saenz Julienne , linux-kernel@vger.kernel.org Subject: [PATCH 2/4] of: property: Do not link to disabled devices Date: Wed, 15 Apr 2020 17:05:47 +0200 Message-Id: <20200415150550.28156-3-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200415150550.28156-1-nsaenzjulienne@suse.de> References: <20200415150550.28156-1-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 device link 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 --- drivers/of/property.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/of/property.c b/drivers/of/property.c index a8c2b13521b27..487685ff8bb19 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1052,6 +1052,13 @@ static int of_link_to_phandle(struct device *dev, struct device_node *sup_np, return -ENODEV; } + /* 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; + } + /* * Don't allow linking a device node as a consumer of one of its * descendant nodes. By definition, a child node can't be a functional -- 2.26.0