powerpc/powernv: Don't crash if there are no OPAL consoles

Some machines might provide the console via a different mechanism
such as direct access to a UART from Linux, in which case OPAL
might not expose any console. In that case, the code would cause
a NULL dereference.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 7c25346..2911abe 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -380,18 +380,20 @@ static int __init opal_init(void)
                pr_warn("opal: Node not found\n");
                return -ENODEV;
        }
+
+       /* Register OPAL consoles if any ports */
        if (firmware_has_feature(FW_FEATURE_OPALv2))
                consoles = of_find_node_by_path("/ibm,opal/consoles");
        else
                consoles = of_node_get(opal_node);
-
-       /* Register serial ports */
-       for_each_child_of_node(consoles, np) {
-               if (strcmp(np->name, "serial"))
-                       continue;
-               of_platform_device_create(np, NULL, NULL);
+       if (consoles) {
+               for_each_child_of_node(consoles, np) {
+                       if (strcmp(np->name, "serial"))
+                               continue;
+                       of_platform_device_create(np, NULL, NULL);
+               }
+               of_node_put(consoles);
        }
-       of_node_put(consoles);
 
        /* Find all OPAL interrupts and request them */
        irqs = of_get_property(opal_node, "opal-interrupts", &irqlen);