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>

1 files changed, 9 insertions, 7 deletions

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 7c253469f23b..2911abe550f1 100644
--- 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);