diff --git a/kernel/resource.c b/kernel/resource.c
index 38b8d11c9eaf46233028dc30c36b79c97399a62f..bce773cc5e4169022d8a1f5fbc6380771ae41fe2 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -325,7 +325,7 @@ EXPORT_SYMBOL(release_resource);
  *
  * If a resource is found, returns 0 and *res is overwritten with the part
  * of the resource that's within [start..end]; if none is found, returns
- * -1.
+ * -ENODEV.  Returns -EINVAL for invalid parameters.
  *
  * This function walks the whole tree and not just first level children
  * unless @first_level_children_only is true.
@@ -359,16 +359,16 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 			break;
 	}
 
+	if (p) {
+		/* copy data */
+		res->start = max(start, p->start);
+		res->end = min(end, p->end);
+		res->flags = p->flags;
+		res->desc = p->desc;
+	}
+
 	read_unlock(&resource_lock);
-	if (!p)
-		return -1;
-
-	/* copy data */
-	res->start = max(start, p->start);
-	res->end = min(end, p->end);
-	res->flags = p->flags;
-	res->desc = p->desc;
-	return 0;
+	return p ? 0 : -ENODEV;
 }
 
 static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,