[PATCH v2] media: xilinx: fix leaked of_node references

[Wen Yang]

The call to of_get_child_by_name returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
drivers/media/platform/xilinx/xilinx-vipp.c:487:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 477, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-vipp.c:491:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 477, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:732:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:741:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:757:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.
drivers/media/platform/xilinx/xilinx-tpg.c:764:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 717, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Cc: Patrice Chotard <patrice.chotard@xxxxxx>
Cc: Hyun Kwon <hyun.kwon@xxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: Michal Simek <michal.simek@xxxxxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
v2: fix Comparison to NULL

 drivers/media/platform/xilinx/xilinx-tpg.c  | 18 +++++++++++++-----
 drivers/media/platform/xilinx/xilinx-vipp.c |  8 +++++---
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/xilinx/xilinx-tpg.c b/drivers/media/platform/xilinx/xilinx-tpg.c
index ed01bed..e71d022 100644
--- a/drivers/media/platform/xilinx/xilinx-tpg.c
+++ b/drivers/media/platform/xilinx/xilinx-tpg.c
@@ -713,10 +713,13 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)
 	struct device_node *port;
 	unsigned int nports = 0;
 	bool has_endpoint = false;
+	int ret = 0;
 
 	ports = of_get_child_by_name(node, "ports");
-	if (ports == NULL)
+	if (!ports) {
 		ports = node;
+		of_node_get(ports);
+	}
 
 	for_each_child_of_node(ports, port) {
 		const struct xvip_video_format *format;
@@ -729,7 +732,8 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)
 		if (IS_ERR(format)) {
 			dev_err(dev, "invalid format in DT");
 			of_node_put(port);
-			return PTR_ERR(format);
+			ret = PTR_ERR(format);
+			goto out_put_node;
 		}
 
 		/* Get and check the format description */
@@ -738,7 +742,8 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)
 		} else if (xtpg->vip_format != format) {
 			dev_err(dev, "in/out format mismatch in DT");
 			of_node_put(port);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out_put_node;
 		}
 
 		if (nports == 0) {
@@ -754,14 +759,17 @@ static int xtpg_parse_of(struct xtpg_device *xtpg)
 
 	if (nports != 1 && nports != 2) {
 		dev_err(dev, "invalid number of ports %u\n", nports);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out_put_node;
 	}
 
 	xtpg->npads = nports;
 	if (nports == 2 && has_endpoint)
 		xtpg->has_input = true;
 
-	return 0;
+out_put_node:
+	of_node_put(ports);
+	return ret;
 }
 
 static int xtpg_probe(struct platform_device *pdev)
diff --git a/drivers/media/platform/xilinx/xilinx-vipp.c b/drivers/media/platform/xilinx/xilinx-vipp.c
index edce040..307717c 100644
--- a/drivers/media/platform/xilinx/xilinx-vipp.c
+++ b/drivers/media/platform/xilinx/xilinx-vipp.c
@@ -472,7 +472,7 @@ static int xvip_graph_dma_init(struct xvip_composite_device *xdev)
 {
 	struct device_node *ports;
 	struct device_node *port;
-	int ret;
+	int ret = 0;
 
 	ports = of_get_child_by_name(xdev->dev->of_node, "ports");
 	if (ports == NULL) {
@@ -484,11 +484,13 @@ static int xvip_graph_dma_init(struct xvip_composite_device *xdev)
 		ret = xvip_graph_dma_init_one(xdev, port);
 		if (ret < 0) {
 			of_node_put(port);
-			return ret;
+			goto out_put_node;
 		}
 	}
 
-	return 0;
+out_put_node:
+	of_node_put(ports);
+	return ret;
 }
 
 static void xvip_graph_cleanup(struct xvip_composite_device *xdev)
-- 
2.9.5