[PATCH 4/6] clocksource/drivers/davinci: Fix clock reference leak in of_davinci_timer_register

[Wentao Liang]

of_davinci_timer_register() looks up the timer clock with of_clk_get(),
which takes a reference on the clock, and passes it to
davinci_timer_register(). That function enables the clock and keeps it
enabled for the lifetime of the timer, but it never takes ownership of
the reference and never calls clk_put(); only the error paths of
of_davinci_timer_register() dropped the reference, so on success the
reference obtained by of_clk_get() leaked.

Drop the reference unconditionally after davinci_timer_register()
returns: on failure the clock has already been disabled and unprepared
by davinci_timer_register(), and on success the clock stays enabled
while the consumer reference is released.

Fixes: 721154f972aa ("clocksource/drivers/davinci: Add support for clockevents")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
 drivers/clocksource/timer-davinci.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/timer-davinci.c b/drivers/clocksource/timer-davinci.c
index 16ee0687ef31..54700738fcd4 100644
--- a/drivers/clocksource/timer-davinci.c
+++ b/drivers/clocksource/timer-davinci.c
@@ -376,8 +376,11 @@ static int __init of_davinci_timer_register(struct device_node *np)
 	}
 
 	rv = davinci_timer_register(clk, &timer_cfg);
-	if (rv)
-		clk_put(clk);
+	/*
+	 * The clock is left enabled on success, but the consumer reference
+	 * taken by of_clk_get() is not needed anymore in either case.
+	 */
+	clk_put(clk);
 
 	return rv;
 }
-- 
2.34.1