[PATCH] thermal: fix multiple disbalanced device node counters

[Vladimir Zapolskiy <vz@mleia.com>]

Here on function return all temporarily used device nodes shall
decrement their usage counter. The problems are found with device
nodes allocated by for_each_child_of_node(), of_parse_phandle()
and of_find_node_by_name(), fix all problems at once.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: devicetree@vger.kernel.org
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
---
 drivers/thermal/of-thermal.c |   40 ++++++++++++++++++++++++++++++++--------
 1 file changed, 32 insertions(+), 8 deletions(-)

diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index f8eb625..62143ba 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -387,15 +387,18 @@ thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
 				int (*get_trend)(void *, long *))
 {
 	struct device_node *np, *child, *sensor_np;
+	struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
 
 	np = of_find_node_by_name(NULL, "thermal-zones");
 	if (!np)
 		return ERR_PTR(-ENODEV);
 
-	if (!dev || !dev->of_node)
+	if (!dev || !dev->of_node) {
+		of_node_put(np);
 		return ERR_PTR(-EINVAL);
+	}
 
-	sensor_np = dev->of_node;
+	sensor_np = of_node_get(dev->of_node);
 
 	for_each_child_of_node(np, child) {
 		struct of_phandle_args sensor_specs;
@@ -422,16 +425,21 @@ thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
 		}
 
 		if (sensor_specs.np == sensor_np && id == sensor_id) {
-			of_node_put(np);
-			return thermal_zone_of_add_sensor(child, sensor_np,
-							  data,
-							  get_temp,
-							  get_trend);
+			tzd = thermal_zone_of_add_sensor(child, sensor_np,
+							 data,
+							 get_temp,
+							 get_trend);
+			of_node_put(sensor_specs.np);
+			of_node_put(child);
+			goto exit;
 		}
+		of_node_put(sensor_specs.np);
 	}
+exit:
+	of_node_put(sensor_np);
 	of_node_put(np);
 
-	return ERR_PTR(-ENODEV);
+	return tzd;
 }
 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
 
@@ -623,6 +631,7 @@ static int thermal_of_populate_trip(struct device_node *np,
 
 	/* Required for cooling map matching */
 	trip->np = np;
+	of_node_get(np);
 
 	return 0;
 }
@@ -730,9 +739,14 @@ finish:
 	return tz;
 
 free_tbps:
+	for (i = 0; i < tz->num_tbps; i++)
+		of_node_put(tz->tbps[i].cooling_device);
 	kfree(tz->tbps);
 free_trips:
+	for (i = 0; i < tz->ntrips; i++)
+		of_node_put(tz->trips[i].np);
 	kfree(tz->trips);
+	of_node_put(gchild);
 free_tz:
 	kfree(tz);
 	of_node_put(child);
@@ -742,7 +756,13 @@ free_tz:
 
 static inline void of_thermal_free_zone(struct __thermal_zone *tz)
 {
+	int i;
+
+	for (i = 0; i < tz->num_tbps; i++)
+		of_node_put(tz->tbps[i].cooling_device);
 	kfree(tz->tbps);
+	for (i = 0; i < tz->ntrips; i++)
+		of_node_put(tz->trips[i].np);
 	kfree(tz->trips);
 	kfree(tz);
 }
@@ -814,10 +834,13 @@ int __init of_parse_thermal_zones(void)
 			/* attempting to build remaining zones still */
 		}
 	}
+	of_node_put(np);
 
 	return 0;
 
 exit_free:
+	of_node_put(child);
+	of_node_put(np);
 	of_thermal_free_zone(tz);
 
 	/* no memory available, so free what we have built */
@@ -859,4 +882,5 @@ void of_thermal_destroy_zones(void)
 		kfree(zone->ops);
 		of_thermal_free_zone(zone->devdata);
 	}
+	of_node_put(np);
 }
-- 
1.7.10.4