path: root/drivers/hwmon/lm90.c
diff options
authorJean Delvare <khali@linux-fr.org>2008-10-26 17:04:39 +0100
committerJean Delvare <khali@linux-fr.org>2008-10-26 17:04:39 +0100
commitec38fa2b35f13e7fa1d676a5bc997d0df1b02574 (patch)
treedf2ffd6eb0af65516cf0aae37c80c9fd1eee5dc6 /drivers/hwmon/lm90.c
parent1b871826b3dfcdcd78140d17c00e452eec6c12a4 (diff)
hwmon: (lm90) Fix handling of hysteresis value
There are several problems in the way the hysteresis value is handled by the lm90 driver: * In show_temphyst(), specific handling of the MAX6646 is missing, so the hysteresis is reported incorrectly if the critical temperature is over 127 degrees C. * In set_temphyst(), the new hysteresis register value is written to the chip but data->temp_hyst isn't updated accordingly, so there is a short period of time (up to 2 seconds) where the old hystereris value will be returned while the new one is already active. * In set_temphyst(), the critical temperature which is used as a base to compute the value of the hysteresis register lacks device-specific handling. As a result, the value of the hysteresis register might be incorrect for the ADT7461 and MAX6646 chips. Fix these 3 bugs. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Nate Case <ncase@xes-inc.com>
Diffstat (limited to 'drivers/hwmon/lm90.c')
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 3edeebc0b835..6242e72a82c1 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -461,6 +461,8 @@ static ssize_t show_temphyst(struct device *dev, struct device_attribute *devatt
if (data->kind == adt7461)
temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
+ else if (data->kind == max6646)
+ temp = temp_from_u8(data->temp8[attr->index]);
temp = temp_from_s8(data->temp8[attr->index]);
@@ -473,12 +475,19 @@ static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
struct i2c_client *client = to_i2c_client(dev);
struct lm90_data *data = i2c_get_clientdata(client);
long val = simple_strtol(buf, NULL, 10);
- long hyst;
+ int temp;
- hyst = temp_from_s8(data->temp8[2]) - val;
+ if (data->kind == adt7461)
+ temp = temp_from_u8_adt7461(data, data->temp8[2]);
+ else if (data->kind == max6646)
+ temp = temp_from_u8(data->temp8[2]);
+ else
+ temp = temp_from_s8(data->temp8[2]);
+ data->temp_hyst = hyst_to_reg(temp - val);
i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
- hyst_to_reg(hyst));
+ data->temp_hyst);
return count;