PCI: OF: Don't crash when bridge parent is NULL.

In pcibios_get_phb_of_node(), we will crash while booting if
bus->bridge->parent is NULL.

Check for this case and avoid dereferencing the NULL pointer.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index c94d37e..f092993 100644 (file)
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -55,7 +55,7 @@ struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
         */
        if (bus->bridge->of_node)
                return of_node_get(bus->bridge->of_node);
-       if (bus->bridge->parent->of_node)
+       if (bus->bridge->parent && bus->bridge->parent->of_node)
                return of_node_get(bus->bridge->parent->of_node);
        return NULL;
 }