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authorJean Delvare <khali@linux-fr.org>2010-04-14 18:14:09 +0400
committerJean Delvare <khali@linux-fr.org>2010-04-14 18:14:09 +0400
commit8acf07c5a7674e53f2d320d540aec5d714b105cf (patch)
tree4a7f46597031fcede0c2fdd6851e353784070758
parenta00afb97e23fd904b12a3f4de3237d8ab2f68738 (diff)
downloadlinux-8acf07c5a7674e53f2d320d540aec5d714b105cf.tar.xz
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>
-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 5e39e2d40380..a65ba31cad29 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;