drm/meson: add missing of_node_put

[ Upstream commit f672b93e4a0a4947d2e1103ed8780e01e13eadb6 ]

Add an of_node_put when the result of of_graph_get_remote_port_parent is
not available.

An of_node_put is also needed when meson_probe_remote completes.  This was
present at the recursive call, but not in the call from meson_drv_probe.

The semantic match that finds this problem is as follows
(http://coccinelle.lip6.fr):

// <smpl>
@r exists@
local idexpression e;
expression x;
@@
e = of_graph_get_remote_port_parent(...);
... when != x = e
    when != true e == NULL
    when != of_node_put(e)
    when != of_fwnode_handle(e)
(
return e;
|
*return ...;
)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1547372691-28324-4-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index bf5f294f172fa221667ff2f3250df645a0fadc47..611ac340fb2892c90568dc5fc21c87311762da31 100644 (file)
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -368,8 +368,10 @@ static int meson_probe_remote(struct platform_device *pdev,
                remote_node = of_graph_get_remote_port_parent(ep);
                if (!remote_node ||
                    remote_node == parent || /* Ignore parent endpoint */
-                   !of_device_is_available(remote_node))
+                   !of_device_is_available(remote_node)) {
+                       of_node_put(remote_node);
                        continue;
+               }
 
                count += meson_probe_remote(pdev, match, remote, remote_node);
 
@@ -388,10 +390,13 @@ static int meson_drv_probe(struct platform_device *pdev)
 
        for_each_endpoint_of_node(np, ep) {
                remote = of_graph_get_remote_port_parent(ep);
-               if (!remote || !of_device_is_available(remote))
+               if (!remote || !of_device_is_available(remote)) {
+                       of_node_put(remote);
                        continue;
+               }
 
                count += meson_probe_remote(pdev, &match, np, remote);
+               of_node_put(remote);
        }
 
        if (count && !match)