From patchwork Thu Jun 4 06:41:59 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 6544201 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 2E20F9F6CE for ; Thu, 4 Jun 2015 06:44:17 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 602172074E for ; Thu, 4 Jun 2015 06:44:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 743F320752 for ; Thu, 4 Jun 2015 06:44:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752465AbbFDGoN (ORCPT ); Thu, 4 Jun 2015 02:44:13 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:38570 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752571AbbFDGoD (ORCPT ); Thu, 4 Jun 2015 02:44:03 -0400 Received: from /spool/local by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 4 Jun 2015 16:44:02 +1000 Received: from d23dlp03.au.ibm.com (202.81.31.214) by e23smtp01.au.ibm.com (202.81.31.207) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 4 Jun 2015 16:44:00 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 95FFC3578054; Thu, 4 Jun 2015 16:43:59 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t546hpt438142044; Thu, 4 Jun 2015 16:43:59 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t546hPCu014338; Thu, 4 Jun 2015 16:43:27 +1000 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id t546hP51013814; Thu, 4 Jun 2015 16:43:25 +1000 Received: from bran.ozlabs.ibm.com (unknown [9.192.254.114]) by ozlabs.au.ibm.com (Postfix) with ESMTP id E0E7FA040C; Thu, 4 Jun 2015 16:42:35 +1000 (AEST) Received: from gwshan (shangw.ozlabs.ibm.com [10.61.2.199]) by bran.ozlabs.ibm.com (Postfix) with ESMTP id EBE94E387C; Thu, 4 Jun 2015 16:42:35 +1000 (AEST) Received: by gwshan (Postfix, from userid 1000) id DB1009422B2; Thu, 4 Jun 2015 16:42:35 +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, bhelgaas@google.com, aik@ozlabs.ru, panto@antoniou-consulting.com, robherring2@gmail.com, grant.likely@linaro.org, Gavin Shan Subject: [PATCH v5 30/42] powerpc/pci: Don't scan empty slot Date: Thu, 4 Jun 2015 16:41:59 +1000 Message-Id: <1433400131-18429-31-git-send-email-gwshan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1433400131-18429-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1433400131-18429-1-git-send-email-gwshan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15060406-1618-0000-0000-0000023555C8 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. The patch adds condition of skipping scanning PCI bus without child devices, in order to avoid kernel crash. Signed-off-by: Gavin Shan --- v5: * Derived from PATCH[v4 11/21] --- 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 21973e7..ca392fc 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