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authorJean Delvare <khali@linux-fr.org>2010-04-14 16:14:09 +0200
committerJean Delvare <khali@linux-fr.org>2010-04-14 16:14:09 +0200
commit8acf07c5a7674e53f2d320d540aec5d714b105cf (patch)
tree4a7f46597031fcede0c2fdd6851e353784070758 /drivers/hwmon/it87.c
parenta00afb97e23fd904b12a3f4de3237d8ab2f68738 (diff)
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: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/hwmon/it87.c')
-rw-r--r--drivers/hwmon/it87.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index 5e39e2d4038..a65ba31cad2 100644
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -539,15 +539,14 @@ static ssize_t set_sensor(struct device *dev, struct device_attribute *attr,
struct it87_data *data = dev_get_drvdata(dev);
long val;
+ u8 reg;
if (strict_strtol(buf, 10, &val) < 0)
return -EINVAL;
- mutex_lock(&data->update_lock);
-
- data->sensor = it87_read_value(data, IT87_REG_TEMP_ENABLE);
- data->sensor &= ~(1 << nr);
- data->sensor &= ~(8 << nr);
+ reg = it87_read_value(data, IT87_REG_TEMP_ENABLE);
+ reg &= ~(1 << nr);
+ reg &= ~(8 << nr);
if (val == 2) { /* backwards compatibility */
dev_warn(dev, "Sensor type 2 is deprecated, please use 4 "
"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 */
if (val == 3)
- data->sensor |= 1 << nr;
+ reg |= 1 << nr;
else if (val == 4)
- data->sensor |= 8 << nr;
- else if (val != 0) {
- mutex_unlock(&data->update_lock);
+ reg |= 8 << nr;
+ else if (val != 0)
return -EINVAL;
- }
+
+ mutex_lock(&data->update_lock);
+ data->sensor = reg;
it87_write_value(data, IT87_REG_TEMP_ENABLE, data->sensor);
mutex_unlock(&data->update_lock);
return count;