From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp09.au.ibm.com ([202.81.31.142]:34089 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753313AbbEAGEh (ORCPT ); Fri, 1 May 2015 02:04:37 -0400 Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 1 May 2015 16:04:35 +1000 Received: from d23relay08.au.ibm.com (d23relay08.au.ibm.com [9.185.71.33]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id C2A7E3578058 for ; Fri, 1 May 2015 16:04:33 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay08.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t4164P0V13959422 for ; Fri, 1 May 2015 16:04:33 +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 t4163xck005989 for ; Fri, 1 May 2015 16:04:00 +1000 From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org, benh@kernel.crashing.org, bhelgaas@google.com, Gavin Shan Subject: [PATCH v4 11/21] powerpc/pci: Don't scan empty slot Date: Fri, 1 May 2015 16:02:58 +1000 Message-Id: <1430460188-31343-12-git-send-email-gwshan@linux.vnet.ibm.com> In-Reply-To: <1430460188-31343-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1430460188-31343-1-git-send-email-gwshan@linux.vnet.ibm.com> Sender: linux-pci-owner@vger.kernel.org List-ID: 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 --- 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 0040343..651a866a 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 -- 2.1.0