[PATCH] iio: mlx90614: fix missing GPIO direction return value checks

[Salah Triki]

The functions gpiod_direction_output() and gpiod_direction_input() can
fail, but their return values were previously ignored.

If an error occurs during the GPIO configuration, the function should
abort the wake-up sequence and return the error code. More importantly,
failing to check these values could lead to the I2C bus remaining
locked if an error occurs after i2c_lock_bus() is called.

Add return value checks and ensure the I2C bus is properly unlocked
via a goto label in case of failure.

Fixes: eb4b07dae4d4 ("iio: mlx90614: Add power management")
Signed-off-by: Salah Triki <salah.triki@xxxxxxxxx>
---
 drivers/iio/temperature/mlx90614.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/temperature/mlx90614.c b/drivers/iio/temperature/mlx90614.c
index 1ad21b73e1b4..ce12b44c84e0 100644
--- a/drivers/iio/temperature/mlx90614.c
+++ b/drivers/iio/temperature/mlx90614.c
@@ -489,6 +489,7 @@ static int mlx90614_sleep(struct mlx90614_data *data)
 static int mlx90614_wakeup(struct mlx90614_data *data)
 {
 	const struct mlx_chip_info *chip_info = data->chip_info;
+	int ret;
 
 	if (!data->wakeup_gpio) {
 		dev_dbg(&data->client->dev, "Wake-up disabled");
@@ -498,9 +499,17 @@ static int mlx90614_wakeup(struct mlx90614_data *data)
 	dev_dbg(&data->client->dev, "Requesting wake-up");
 
 	i2c_lock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
-	gpiod_direction_output(data->wakeup_gpio, 0);
+
+	ret = gpiod_direction_output(data->wakeup_gpio, 0);
+	if (ret)
+		goto out_unlock;
+
 	msleep(chip_info->wakeup_delay_ms);
-	gpiod_direction_input(data->wakeup_gpio);
+
+	ret = gpiod_direction_input(data->wakeup_gpio);
+	if (ret)
+		goto out_unlock;
+
 	i2c_unlock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
 
 	data->ready_timestamp = jiffies +
@@ -515,6 +524,10 @@ static int mlx90614_wakeup(struct mlx90614_data *data)
 	i2c_smbus_read_word_data(data->client, chip_info->op_eeprom_config1);
 
 	return 0;
+
+out_unlock:
+	i2c_unlock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
+	return ret;
 }
 
 /* Return wake-up GPIO or NULL if sleep functionality should be disabled. */
-- 
2.43.0