From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp01.au.ibm.com ([202.81.31.143]:46535 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965175AbcBQDqB (ORCPT ); Tue, 16 Feb 2016 22:46:01 -0500 Received: from localhost by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 17 Feb 2016 13:45:59 +1000 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, dja@axtens.net, bhelgaas@google.com, robherring2@gmail.com, grant.likely@linaro.org, Gavin Shan Subject: [PATCH v8 31/45] powerpc/pci: Don't scan empty slot Date: Wed, 17 Feb 2016 14:44:14 +1100 Message-Id: <1455680668-23298-32-git-send-email-gwshan@linux.vnet.ibm.com> In-Reply-To: <1455680668-23298-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1455680668-23298-1-git-send-email-gwshan@linux.vnet.ibm.com> Sender: linux-pci-owner@vger.kernel.org List-ID: In hotplug case, function pci_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 one more check to skip scanning PCI bus that doesn't have any subordinate devices from device-tree, 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 7929a1c..3628c38 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 -- 2.1.0