From mboxrd@z Thu Jan 1 00:00:00 1970 From: 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> References: <1438834307-26960-1-git-send-email-gwshan@linux.vnet.ibm.com> Return-path: In-Reply-To: <1438834307-26960-1-git-send-email-gwshan@linux.vnet.ibm.com> Sender: linux-pci-owner@vger.kernel.org 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 List-Id: devicetree@vger.kernel.org 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 -- 2.1.0