of: Improve prom_update_property() function

prom_update_property() currently fails if the property doesn't
actually exist yet which isn't what we want. Change to add-or-update
instead of update-only, then we can remove a lot duplicated lines.

Suggested-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index eada3f4ef801..bc86ea2af668 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1073,7 +1073,8 @@ int prom_remove_property(struct device_node *np, struct property *prop)
 }
 
 /*
- * prom_update_property - Update a property in a node.
+ * prom_update_property - Update a property in a node, if the property does
+ * not exist, add it.
  *
  * Note that we don't actually remove it, since we have given out
  * who-knows-how-many pointers to the data using get-property.
@@ -1081,13 +1082,19 @@ int prom_remove_property(struct device_node *np, struct property *prop)
  * and add the new property to the property list
  */
 int prom_update_property(struct device_node *np,
-                         struct property *newprop,
-                         struct property *oldprop)
+                         struct property *newprop)
 {
-        struct property **next;
+        struct property **next, *oldprop;
         unsigned long flags;
         int found = 0;
 
+        if (!newprop->name)
+                return -EINVAL;
+
+        oldprop = of_find_property(np, newprop->name, NULL);
+        if (!oldprop)
+                return prom_add_property(np, newprop);
+
         write_lock_irqsave(&devtree_lock, flags);
         next = &np->properties;
         while (*next) {