1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index dbd33605cc1..fedae89d8f7 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -121,10 +121,13 @@ void __devinit pci_bus_add_devices(struct pci_bus *bus)
                  * If there is an unattached subordinate bus, attach
                  * it and then scan for unattached PCI devices.
                  */
-                if (dev->subordinate && list_empty(&dev->subordinate->node)) {
-                        spin_lock(&pci_bus_lock);
-                        list_add_tail(&dev->subordinate->node, &dev->bus->children);
-                        spin_unlock(&pci_bus_lock);
+                if (dev->subordinate) {
+                       if (list_empty(&dev->subordinate->node)) {
+                               spin_lock(&pci_bus_lock);
+                               list_add_tail(&dev->subordinate->node,
+                                               &dev->bus->children);
+                               spin_unlock(&pci_bus_lock);
+                       }
                         pci_bus_add_devices(dev->subordinate);
 
                         sysfs_create_link(&dev->subordinate->class_dev.kobj, &dev->dev.kobj, "bridge");