Commit 8acf07c5 authored by Jean Delvare's avatar Jean Delvare
Browse files

hwmon: (it87) Properly handle wrong sensor type requests 



Currently, if someone tries to set the thermal sensor type to an
unsupported value, subsequent accesses to the chip may temporarily
show the sensor in question as disabled. Use a temporary variable
and only update the cached value on success, to prevent such
confusion.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent a00afb97

drivers/hwmon/it87.c

+10 −10
Original line number Original line Diff line number Diff line
@@ -539,15 +539,14 @@ static ssize_t set_sensor(struct device *dev, struct device_attribute *attr, 




	struct it87_data *data = dev_get_drvdata(dev);

	struct it87_data *data = dev_get_drvdata(dev);

	long val;

	long val;

	u8 reg;





	if (strict_strtol(buf, 10, &val) < 0)

	if (strict_strtol(buf, 10, &val) < 0)

		return -EINVAL;

		return -EINVAL;





	mutex_lock(&data->update_lock);

	reg = it87_read_value(data, IT87_REG_TEMP_ENABLE);



	reg &= ~(1 << nr);

	data->sensor = it87_read_value(data, IT87_REG_TEMP_ENABLE);

	reg &= ~(8 << nr);

	data->sensor &= ~(1 << nr);

	data->sensor &= ~(8 << nr);

	if (val == 2) {	/* backwards compatibility */

	if (val == 2) {	/* backwards compatibility */

		dev_warn(dev, "Sensor type 2 is deprecated, please use 4 "

		dev_warn(dev, "Sensor type 2 is deprecated, please use 4 "

			 "instead\n");

			 "instead\n");
@@ -555,13 +554,14 @@ static ssize_t set_sensor(struct device *dev, struct device_attribute *attr, 
	}

	}

	/* 3 = thermal diode; 4 = thermistor; 0 = disabled */

	/* 3 = thermal diode; 4 = thermistor; 0 = disabled */

	if (val == 3)

	if (val == 3)

		data->sensor |= 1 << nr;

		reg |= 1 << nr;

	else if (val == 4)

	else if (val == 4)

		data->sensor |= 8 << nr;

		reg |= 8 << nr;

	else if (val != 0) {

	else if (val != 0)

		mutex_unlock(&data->update_lock);

		return -EINVAL;

		return -EINVAL;

	}



	mutex_lock(&data->update_lock);

	data->sensor = reg;

	it87_write_value(data, IT87_REG_TEMP_ENABLE, data->sensor);

	it87_write_value(data, IT87_REG_TEMP_ENABLE, data->sensor);

	mutex_unlock(&data->update_lock);

	mutex_unlock(&data->update_lock);

	return count;

	return count;

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