[PATCH v3 1/4] iio: accel: bmc150: convert to guard(mutex)

[Rajveer Chaudhari <rajveer.chaudhari.linux@gmail.com>]

Replace manual mutex_lock/mutex_unlock pair with guard(mutex)
in bmc150_accel_buffer_predisable() and
bmc150_accel_buffer_postenable(). This ensures the mutex is
released on all return paths and allows returning directly
without a goto label.

Signed-off-by: Rajveer Chaudhari <rajveer.chaudhari.linux@gmail.com>
---
v3: stop initialising ret=0 at start, making clear about good path.
moved return ret up into the if (ret) {} block in
bmc150_accel_buffer_postenable().

v2: Cleaned mutex_unlock and goto in
bmc150_accel_buffer_postenable(),
Dropped Header alignment change.
---
 drivers/iio/accel/bmc150-accel-core.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c
index 42ccf0316ce5..4772dc6fcee9 100644
--- a/drivers/iio/accel/bmc150-accel-core.c
+++ b/drivers/iio/accel/bmc150-accel-core.c
@@ -7,6 +7,7 @@
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
@@ -1480,20 +1481,20 @@ static int bmc150_accel_buffer_preenable(struct iio_dev *indio_dev)
 static int bmc150_accel_buffer_postenable(struct iio_dev *indio_dev)
 {
 	struct bmc150_accel_data *data = iio_priv(indio_dev);
-	int ret = 0;
+	int ret;
 
 	if (iio_device_get_current_mode(indio_dev) == INDIO_BUFFER_TRIGGERED)
 		return 0;
 
-	mutex_lock(&data->mutex);
+	guard(mutex)(&data->mutex);
 
 	if (!data->watermark)
-		goto out;
+		return 0;
 
 	ret = bmc150_accel_set_interrupt(data, BMC150_ACCEL_INT_WATERMARK,
 					 true);
 	if (ret)
-		goto out;
+		return ret;
 
 	data->fifo_mode = BMC150_ACCEL_FIFO_MODE_FIFO;
 
@@ -1502,12 +1503,10 @@ static int bmc150_accel_buffer_postenable(struct iio_dev *indio_dev)
 		data->fifo_mode = 0;
 		bmc150_accel_set_interrupt(data, BMC150_ACCEL_INT_WATERMARK,
 					   false);
+		return ret;
 	}
 
-out:
-	mutex_unlock(&data->mutex);
-
-	return ret;
+	return 0;
 }
 
 static int bmc150_accel_buffer_predisable(struct iio_dev *indio_dev)
@@ -1517,19 +1516,16 @@ static int bmc150_accel_buffer_predisable(struct iio_dev *indio_dev)
 	if (iio_device_get_current_mode(indio_dev) == INDIO_BUFFER_TRIGGERED)
 		return 0;
 
-	mutex_lock(&data->mutex);
+	guard(mutex)(&data->mutex);
 
 	if (!data->fifo_mode)
-		goto out;
+		return 0;
 
 	bmc150_accel_set_interrupt(data, BMC150_ACCEL_INT_WATERMARK, false);
 	__bmc150_accel_fifo_flush(indio_dev, BMC150_ACCEL_FIFO_LENGTH, false);
 	data->fifo_mode = 0;
 	bmc150_accel_fifo_set_mode(data);
 
-out:
-	mutex_unlock(&data->mutex);
-
 	return 0;
 }
 
-- 
2.53.0