[PATCH v2 20/22] Input: regulator-haptic - use guard notation when acquiring mutex

[Dmitry Torokhov]

Using guard notation 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@xxxxxxxxx>
---

v2: drop no linger used "error" variable in regulator_haptic_suspend()

 drivers/input/misc/regulator-haptic.c |   24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/drivers/input/misc/regulator-haptic.c b/drivers/input/misc/regulator-haptic.c
index 02f73b7c0462..3666ba6d1f30 100644
--- a/drivers/input/misc/regulator-haptic.c
+++ b/drivers/input/misc/regulator-haptic.c
@@ -83,12 +83,10 @@ static void regulator_haptic_work(struct work_struct *work)
 	struct regulator_haptic *haptic = container_of(work,
 					struct regulator_haptic, work);
 
-	mutex_lock(&haptic->mutex);
+	guard(mutex)(&haptic->mutex);
 
 	if (!haptic->suspended)
 		regulator_haptic_set_voltage(haptic, haptic->magnitude);
-
-	mutex_unlock(&haptic->mutex);
 }
 
 static int regulator_haptic_play_effect(struct input_dev *input, void *data,
@@ -205,19 +203,15 @@ static int regulator_haptic_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
-	int error;
 
-	error = mutex_lock_interruptible(&haptic->mutex);
-	if (error)
-		return error;
-
-	regulator_haptic_set_voltage(haptic, 0);
+	scoped_guard(mutex_intr, &haptic->mutex) {
+		regulator_haptic_set_voltage(haptic, 0);
+		haptic->suspended = true;
 
-	haptic->suspended = true;
-
-	mutex_unlock(&haptic->mutex);
+		return 0;
+	}
 
-	return 0;
+	return -EINTR;
 }
 
 static int regulator_haptic_resume(struct device *dev)
@@ -226,7 +220,7 @@ static int regulator_haptic_resume(struct device *dev)
 	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 	unsigned int magnitude;
 
-	mutex_lock(&haptic->mutex);
+	guard(mutex)(&haptic->mutex);
 
 	haptic->suspended = false;
 
@@ -234,8 +228,6 @@ static int regulator_haptic_resume(struct device *dev)
 	if (magnitude)
 		regulator_haptic_set_voltage(haptic, magnitude);
 
-	mutex_unlock(&haptic->mutex);
-
 	return 0;
 }