drm/sun4i: backend: add missing of_node_puts

The device node iterators perform an of_node_get on each
iteration, so a jump out of the loop requires an of_node_put.

Remote and port also have augmented reference counts, so drop them
on each iteration and at the end of the function, respectively.
Remote is only used for the address it contains, not for the
contents of that address, so the reference count can be dropped
immediately.

The semantic patch that fixes the first part of this problem is
as follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression root,e;
local idexpression child;
iterator name for_each_child_of_node;
@@

 for_each_available_child_of_node(root, child) {
   ... when != of_node_put(child)
       when != e = child
+  of_node_put(child);
?  break;
   ...
}
... when != child
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1547369264-24831-5-git-send-email-Julia.Lawall@lip6.fr

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index 9e9255ee59cd83138f5572f0d31df50aec9cc244..a021bab11a4f9b1ee8f0c3172fc42d626ec979e2 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -786,17 +786,18 @@ static struct sun4i_frontend *sun4i_backend_find_frontend(struct sun4i_drv *drv,
                remote = of_graph_get_remote_port_parent(ep);
                if (!remote)
                        continue;
+               of_node_put(remote);
 
                /* does this node match any registered engines? */
                list_for_each_entry(frontend, &drv->frontend_list, list) {
                        if (remote == frontend->node) {
-                               of_node_put(remote);
                                of_node_put(port);
+                               of_node_put(ep);
                                return frontend;
                        }
                }
        }
-
+       of_node_put(port);
        return ERR_PTR(-EINVAL);
 }