iio: light: gp2ap020a00f: fix iio_triggered_buffer_{predisable,postenable} positions

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
the poll functions.

For the predisable hook, the disable code should occur before detaching
the poll func, and for the postenable hook, the poll func should be
attached before the enable code.

This change moves the postenable/predisable hooks into the correct
positions.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/gp2ap020a00f.c

@@ -1390,6 +1390,12 @@ static int gp2ap020a00f_buffer_postenable(struct iio_dev *indio_dev)
 
 	mutex_lock(&data->lock);
 
+	err = iio_triggered_buffer_postenable(indio_dev);
+	if (err < 0) {
+		mutex_unlock(&data->lock);
+		return err;
+	}
+
 	/*
 	 * Enable triggers according to the scan_mask. Enabling either
 	 * LIGHT_CLEAR or LIGHT_IR scan mode results in enabling ALS
@@ -1420,14 +1426,12 @@ static int gp2ap020a00f_buffer_postenable(struct iio_dev *indio_dev)
 		goto error_unlock;
 
 	data->buffer = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
-	if (!data->buffer) {
+	if (!data->buffer)
 		err = -ENOMEM;
-		goto error_unlock;
-	}
-
-	err = iio_triggered_buffer_postenable(indio_dev);
 
 error_unlock:
+	if (err < 0)
+		iio_triggered_buffer_predisable(indio_dev);
 	mutex_unlock(&data->lock);
 
 	return err;
@@ -1436,14 +1440,10 @@ static int gp2ap020a00f_buffer_postenable(struct iio_dev *indio_dev)
 static int gp2ap020a00f_buffer_predisable(struct iio_dev *indio_dev)
 {
 	struct gp2ap020a00f_data *data = iio_priv(indio_dev);
-	int i, err;
+	int i, err = 0;
 
 	mutex_lock(&data->lock);
 
-	err = iio_triggered_buffer_predisable(indio_dev);
-	if (err < 0)
-		goto error_unlock;
-
 	for_each_set_bit(i, indio_dev->active_scan_mask,
 		indio_dev->masklength) {
 		switch (i) {
@@ -1465,7 +1465,8 @@ static int gp2ap020a00f_buffer_predisable(struct iio_dev *indio_dev)
 	if (err == 0)
 		kfree(data->buffer);
 
-error_unlock:
+	iio_triggered_buffer_predisable(indio_dev);
+
 	mutex_unlock(&data->lock);
 
 	return err;