From patchwork Thu Aug 6 04:11:34 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 6955501 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7E4E49F358 for ; Thu, 6 Aug 2015 04:13:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9B185203E3 for ; Thu, 6 Aug 2015 04:13:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3BEA2063D for ; Thu, 6 Aug 2015 04:13:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753229AbbHFENZ (ORCPT ); Thu, 6 Aug 2015 00:13:25 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:56526 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753525AbbHFENT (ORCPT ); Thu, 6 Aug 2015 00:13:19 -0400 Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 6 Aug 2015 14:13:17 +1000 Received: from d23dlp03.au.ibm.com (202.81.31.214) by e23smtp02.au.ibm.com (202.81.31.208) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 6 Aug 2015 14:13:16 +1000 X-Helo: d23dlp03.au.ibm.com X-MailFrom: gwshan@linux.vnet.ibm.com X-RcptTo: linux-pci@vger.kernel.org Received: from d23relay06.au.ibm.com (d23relay06.au.ibm.com [9.185.63.219]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 63CF73578064; Thu, 6 Aug 2015 14:13:15 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t764D6h7065998; Thu, 6 Aug 2015 14:13:14 +1000 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t764Cbvb001284; Thu, 6 Aug 2015 14:12:42 +1000 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id t764CbMT000638; Thu, 6 Aug 2015 14:12:37 +1000 Received: from bran.ozlabs.ibm.com (unknown [9.192.254.114]) by ozlabs.au.ibm.com (Postfix) with ESMTP id 7DF0EA0404; Thu, 6 Aug 2015 14:12:06 +1000 (AEST) Received: from gwshan (shangw.ozlabs.ibm.com [10.61.2.199]) by bran.ozlabs.ibm.com (Postfix) with ESMTP id 71428E38F9; Thu, 6 Aug 2015 14:12:06 +1000 (AEST) Received: by gwshan (Postfix, from userid 1000) id 5582F94222F; Thu, 6 Aug 2015 14:12:06 +1000 (AEST) 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, bhelgaas@google.com, grant.likely@linaro.org, robherring2@gmail.com, panto@antoniou-consulting.com, aik@ozlabs.ru, Gavin Shan Subject: [PATCH v6 29/42] powerpc/pci: Don't scan empty slot Date: Thu, 6 Aug 2015 14:11:34 +1000 Message-Id: <1438834307-26960-30-git-send-email-gwshan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1438834307-26960-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1438834307-26960-1-git-send-email-gwshan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15080604-0005-0000-0000-00000240F953 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.0 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, 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 of skipping scanning PCI bus without child 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 59c4361..c307d9a 100644 --- a/arch/powerpc/kernel/pci-hotplug.c +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -92,7 +92,8 @@ void pcibios_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