linux-kernel - [PATCH v2] clocksource/drivers/integrator-ap: add missing of_node

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Date:   Sun, 25 Nov 2018 00:00:49 -0500
From:   Yangtao Li <tiny.windzz@...il.com>
To:     daniel.lezcano@...aro.org, tglx@...utronix.de
Cc:     linux-kernel@...r.kernel.org, Yangtao Li <tiny.windzz@...il.com>
Subject: [PATCH v2] clocksource/drivers/integrator-ap: add missing of_node_put()

of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
integrator_ap_timer_init_of() doesn't do that.The pri_node and the
sec_node are used as an identifier to compare against the current node,
we can directly drop the refcount after getting the node from path as
it is not used aspointer. In addition, a single variable is needed,
so fix it.

Signed-off-by: Yangtao Li <tiny.windzz@...il.com>
---
Changes in v2:
-update changeelog
-simplify fix
-change two variable to one
---
 drivers/clocksource/timer-integrator-ap.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
index 76e526f58620..bbd0977d579a 100644
--- a/drivers/clocksource/timer-integrator-ap.c
+++ b/drivers/clocksource/timer-integrator-ap.c
@@ -181,8 +181,7 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
 	int irq;
 	struct clk *clk;
 	unsigned long rate;
-	struct device_node *pri_node;
-	struct device_node *sec_node;
+	struct device_node *alias_node;
 
 	base = of_io_request_and_map(node, 0, "integrator-timer");
 	if (IS_ERR(base))
@@ -204,7 +203,14 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
 		return err;
 	}
 
-	pri_node = of_find_node_by_path(path);
+	alias_node = of_find_node_by_path(path);
+
+	/* Drop the refcount of node */
+	of_node_put(alias_node);
+
+	if (node == alias_node)
+		/* The primary timer lacks IRQ, use as clocksource */
+		return integrator_clocksource_init(rate, base);
 
 	err = of_property_read_string(of_aliases,
 				"arm,timer-secondary", &path);
@@ -213,14 +219,12 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
 		return err;
 	}
 
+	alias_node = of_find_node_by_path(path);
 
-	sec_node = of_find_node_by_path(path);
-
-	if (node == pri_node)
-		/* The primary timer lacks IRQ, use as clocksource */
-		return integrator_clocksource_init(rate, base);
+	/* Drop the refcount of node */
+	of_node_put(alias_node);
 
-	if (node == sec_node) {
+	if (node == alias_node) {
 		/* The secondary timer will drive the clock event */
 		irq = irq_of_parse_and_map(node, 0);
 		return integrator_clockevent_init(rate, base, irq);
-- 
2.17.0