From patchwork Wed Nov 4 13:12:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 7550191 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 5DF13BEEA4 for ; Wed, 4 Nov 2015 13:26:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 776092054B for ; Wed, 4 Nov 2015 13:26:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EAD032053A for ; Wed, 4 Nov 2015 13:26:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752296AbbKDN0D (ORCPT ); Wed, 4 Nov 2015 08:26:03 -0500 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:49290 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751891AbbKDN0C (ORCPT ); Wed, 4 Nov 2015 08:26:02 -0500 Received: from /spool/local by e28smtp02.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 4 Nov 2015 18:55:59 +0530 Received: from d28dlp03.in.ibm.com (9.184.220.128) by e28smtp02.in.ibm.com (192.168.1.132) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 4 Nov 2015 18:55:57 +0530 X-Helo: d28dlp03.in.ibm.com X-MailFrom: gwshan@linux.vnet.ibm.com X-RcptTo: linux-pci@vger.kernel.org Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id CF8591258059; Wed, 4 Nov 2015 18:55:56 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay05.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tA4DGnBN45809870; Wed, 4 Nov 2015 18:55:56 +0530 Received: from d28av05.in.ibm.com (localhost [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tA4DDJaB031360; Wed, 4 Nov 2015 18:43:21 +0530 Received: from gwshan ([9.192.177.12]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with SMTP id tA4DDAOX030585; Wed, 4 Nov 2015 18:43:16 +0530 Received: by gwshan (Postfix, from userid 1000) id 8507B942D01; Thu, 5 Nov 2015 00:13:07 +1100 (AEDT) From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org, devicetree@vger.kernel.org, benh@kernel.crashing.org, mpe@ellerman.id.au, aik@ozlabs.ru, bhelgaas@google.com, grant.likely@linaro.org, robherring2@gmail.com, panto@antoniou-consulting.com, frowand.list@gmail.com, Gavin Shan Subject: [PATCH v7 35/50] powerpc/pci: Don't scan empty slot Date: Thu, 5 Nov 2015 00:12:35 +1100 Message-Id: <1446642770-4681-36-git-send-email-gwshan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1446642770-4681-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1446642770-4681-1-git-send-email-gwshan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15110413-0005-0000-0000-000008838BA7 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In hotplug case, function pcibios_add_pci_devices() is called to rescan the specified PCI bus, which might not have any child devices. Access to the PCI bus's child device node will cause kernel crash without exception. This adds condition to skip scanning PCI bus that doesn't have any subordinate devices, in order to avoid kernel crash. Signed-off-by: Gavin Shan --- arch/powerpc/kernel/pci-hotplug.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c index 96e2cc3..825b39c 100644 --- a/arch/powerpc/kernel/pci-hotplug.c +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -120,7 +120,8 @@ void pci_add_pci_devices(struct pci_bus *bus) if (mode == PCI_PROBE_DEVTREE) { /* use ofdt-based probe */ of_rescan_bus(dn, bus); - } else if (mode == PCI_PROBE_NORMAL) { + } else if (mode == PCI_PROBE_NORMAL && + dn->child && PCI_DN(dn->child)) { /* * Use legacy probe. In the partial hotplug case, we * probably have grandchildren devices unplugged. So