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 <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/staging/iio/light/tsl2x7x.c

···
 {
 	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);
+	if (device_status == TSL2X7X_CHIP_WORKING) {
+		ret = tsl2x7x_chip_off(indio_dev);
+		if (ret < 0)
+			goto unlock;
+	}
 
-	tsl2x7x_chip_on(indio_dev);
+	ret = tsl2x7x_chip_on(indio_dev);
 
-	if (device_status != TSL2X7X_CHIP_WORKING)
-		tsl2x7x_chip_off(indio_dev);
-
+unlock:
 	mutex_unlock(&chip->prox_mutex);
 	mutex_unlock(&chip->als_mutex);
 
-	return 0;
+	return ret;
 }
 
 static
···
 	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;
···
 	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;
 }
···
 	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;
 }
···
 	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;
 }
···
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	bool value;
+	int ret;
 
 	if (strtobool(buf, &value))
 		return -EINVAL;
···
 	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;
 }
···
 	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);
 
···
 	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;
 }
···
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	bool value;
+	int ret;
 
 	if (strtobool(buf, &value))
 		return -EINVAL;
···
 	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;
 }
···
 					  int val)
 {
 	struct tsl2X7X_chip *chip = iio_priv(indio_dev);
+	int ret;
 
 	if (chan->type == IIO_INTENSITY) {
 		if (val)
···
 			chip->tsl2x7x_settings.interrupts_en &= 0x10;
 	}
 
-	tsl2x7x_invoke_change(indio_dev);
+	ret = tsl2x7x_invoke_change(indio_dev);
+	if (ret < 0)
+		return ret;
 
 	return 0;
 }
···
 		return -EINVAL;
 	}
 
-	tsl2x7x_invoke_change(indio_dev);
-
-	return 0;
+	return tsl2x7x_invoke_change(indio_dev);
 }
 
 static DEVICE_ATTR_RO(in_proximity0_calibscale_available);