[PATCH 16/17] Input: st-keyscan - use guard notation when acquiring mutex

[Dmitry Torokhov]

This makes the code more compact and error handling more robust
by ensuring that mutexes are released in all code paths when control
leaves critical section.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
---
 drivers/input/keyboard/st-keyscan.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/input/keyboard/st-keyscan.c b/drivers/input/keyboard/st-keyscan.c
index 0d27324af809..e53ef4c670e4 100644
--- a/drivers/input/keyboard/st-keyscan.c
+++ b/drivers/input/keyboard/st-keyscan.c
@@ -216,14 +216,13 @@ static int keyscan_suspend(struct device *dev)
 	struct st_keyscan *keypad = platform_get_drvdata(pdev);
 	struct input_dev *input = keypad->input_dev;
 
-	mutex_lock(&input->mutex);
+	guard(mutex)(&input->mutex);
 
 	if (device_may_wakeup(dev))
 		enable_irq_wake(keypad->irq);
 	else if (input_device_enabled(input))
 		keyscan_stop(keypad);
 
-	mutex_unlock(&input->mutex);
 	return 0;
 }
 
@@ -232,17 +231,19 @@ static int keyscan_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct st_keyscan *keypad = platform_get_drvdata(pdev);
 	struct input_dev *input = keypad->input_dev;
-	int retval = 0;
+	int error;
 
-	mutex_lock(&input->mutex);
+	guard(mutex)(&input->mutex);
 
-	if (device_may_wakeup(dev))
+	if (device_may_wakeup(dev)) {
 		disable_irq_wake(keypad->irq);
-	else if (input_device_enabled(input))
-		retval = keyscan_start(keypad);
+	} else if (input_device_enabled(input)) {
+		error = keyscan_start(keypad);
+		if (error)
+			return error;
+	}
 
-	mutex_unlock(&input->mutex);
-	return retval;
+	return 0;
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops,
-- 
2.46.0.295.g3b9ea8a38a-goog