staging: iio: tsl2x7x: check return value from tsl2x7x_invoke_change()

The return value from tsl2x7x_invoke_change() was not checked in most
places in the driver. This patch adds the proper error checks. The
return values inside tsl2x7x_invoke_change() are now checked by
this patch as well.

Previously, if there was an error turning the chip back on, then the
driver would attempt to turn the chip off and incorrectly return
success. The code to power off the chip is removed by this patch
since we should fail fast.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/light/tsl2x7x.c

@@ -771,22 +771,24 @@ int tsl2x7x_invoke_change(struct iio_dev *indio_dev)
 {
 	struct tsl2X7X_chip *chip = iio_priv(indio_dev);
 	int device_status = chip->tsl2x7x_chip_status;
+	int ret;
 
 	mutex_lock(&chip->als_mutex);
 	mutex_lock(&chip->prox_mutex);
 
-	if (device_status == TSL2X7X_CHIP_WORKING)
-		tsl2x7x_chip_off(indio_dev);
-
-	tsl2x7x_chip_on(indio_dev);
+	if (device_status == TSL2X7X_CHIP_WORKING) {
+		ret = tsl2x7x_chip_off(indio_dev);
+		if (ret < 0)
+			goto unlock;
+	}
 
-	if (device_status != TSL2X7X_CHIP_WORKING)
-		tsl2x7x_chip_off(indio_dev);
+	ret = tsl2x7x_chip_on(indio_dev);
 
+unlock:
 	mutex_unlock(&chip->prox_mutex);
 	mutex_unlock(&chip->als_mutex);
 
-	return 0;
+	return ret;
 }
 
 static
@@ -965,6 +967,7 @@ static ssize_t in_illuminance0_target_input_store(struct device *dev,
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct tsl2X7X_chip *chip = iio_priv(indio_dev);
 	unsigned long value;
+	int ret;
 
 	if (kstrtoul(buf, 0, &value))
 		return -EINVAL;
@@ -972,7 +975,9 @@ static ssize_t in_illuminance0_target_input_store(struct device *dev,
 	if (value)
 		chip->tsl2x7x_settings.als_cal_target = value;
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
 
 	return len;
 }
@@ -1021,7 +1026,9 @@ static ssize_t in_intensity0_thresh_period_store(struct device *dev,
 	dev_info(&chip->client->dev, "%s: als persistence = %d",
 		 __func__, filter_delay);
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
 
 	return IIO_VAL_INT_PLUS_MICRO;
 }
@@ -1069,7 +1076,10 @@ static ssize_t in_proximity0_thresh_period_store(struct device *dev,
 	dev_info(&chip->client->dev, "%s: prox persistence = %d",
 		 __func__, filter_delay);
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
+
 
 	return IIO_VAL_INT_PLUS_MICRO;
 }
@@ -1080,6 +1090,7 @@ static ssize_t in_illuminance0_calibrate_store(struct device *dev,
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	bool value;
+	int ret;
 
 	if (strtobool(buf, &value))
 		return -EINVAL;
@@ -1087,7 +1098,9 @@ static ssize_t in_illuminance0_calibrate_store(struct device *dev,
 	if (value)
 		tsl2x7x_als_calibrate(indio_dev);
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
 
 	return len;
 }
@@ -1127,7 +1140,7 @@ static ssize_t in_illuminance0_lux_table_store(struct device *dev,
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct tsl2X7X_chip *chip = iio_priv(indio_dev);
 	int value[ARRAY_SIZE(chip->tsl2x7x_device_lux) * 3 + 1];
-	int n;
+	int n, ret;
 
 	get_options(buf, ARRAY_SIZE(value), value);
 
@@ -1155,7 +1168,9 @@ static ssize_t in_illuminance0_lux_table_store(struct device *dev,
 	memset(chip->tsl2x7x_device_lux, 0, sizeof(chip->tsl2x7x_device_lux));
 	memcpy(chip->tsl2x7x_device_lux, &value[1], (value[0] * 4));
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
 
 	return len;
 }
@@ -1166,6 +1181,7 @@ static ssize_t in_proximity0_calibrate_store(struct device *dev,
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	bool value;
+	int ret;
 
 	if (strtobool(buf, &value))
 		return -EINVAL;
@@ -1173,7 +1189,9 @@ static ssize_t in_proximity0_calibrate_store(struct device *dev,
 	if (value)
 		tsl2x7x_prox_cal(indio_dev);
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
 
 	return len;
 }
@@ -1201,6 +1219,7 @@ static int tsl2x7x_write_interrupt_config(struct iio_dev *indio_dev,
 					  int val)
 {
 	struct tsl2X7X_chip *chip = iio_priv(indio_dev);
+	int ret;
 
 	if (chan->type == IIO_INTENSITY) {
 		if (val)
@@ -1214,7 +1233,9 @@ static int tsl2x7x_write_interrupt_config(struct iio_dev *indio_dev,
 			chip->tsl2x7x_settings.interrupts_en &= 0x10;
 	}
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
 
 	return 0;
 }
@@ -1450,9 +1471,7 @@ static int tsl2x7x_write_raw(struct iio_dev *indio_dev,
 		return -EINVAL;
 	}
 
-	tsl2x7x_invoke_change(indio_dev);
-
-	return 0;
+	return tsl2x7x_invoke_change(indio_dev);
 }
 
 static DEVICE_ATTR_RO(in_proximity0_calibscale_available);