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-rw-r--r--drivers/hwmon/nct6775.c32
1 files changed, 19 insertions, 13 deletions
diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
index 2b493d0682af..2a9fc8c9fb9e 100644
--- a/drivers/hwmon/nct6775.c
+++ b/drivers/hwmon/nct6775.c
@@ -2847,6 +2847,8 @@ store_temp_tolerance(struct device *dev, struct device_attribute *attr,
* Fan speed tolerance is a tricky beast, since the associated register is
* a tick counter, but the value is reported and configured as rpm.
* Compute resulting low and high rpm values and report the difference.
+ * A fan speed tolerance only makes sense if a fan target speed has been
+ * configured, so only display values other than 0 if that is the case.
*/
static ssize_t
show_speed_tolerance(struct device *dev, struct device_attribute *attr,
@@ -2855,19 +2857,23 @@ show_speed_tolerance(struct device *dev, struct device_attribute *attr,
struct nct6775_data *data = nct6775_update_device(dev);
struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
int nr = sattr->index;
- int low = data->target_speed[nr] - data->target_speed_tolerance[nr];
- int high = data->target_speed[nr] + data->target_speed_tolerance[nr];
- int tolerance;
-
- if (low <= 0)
- low = 1;
- if (high > 0xffff)
- high = 0xffff;
- if (high < low)
- high = low;
-
- tolerance = (fan_from_reg16(low, data->fan_div[nr])
- - fan_from_reg16(high, data->fan_div[nr])) / 2;
+ int target = data->target_speed[nr];
+ int tolerance = 0;
+
+ if (target) {
+ int low = target - data->target_speed_tolerance[nr];
+ int high = target + data->target_speed_tolerance[nr];
+
+ if (low <= 0)
+ low = 1;
+ if (high > 0xffff)
+ high = 0xffff;
+ if (high < low)
+ high = low;
+
+ tolerance = (fan_from_reg16(low, data->fan_div[nr])
+ - fan_from_reg16(high, data->fan_div[nr])) / 2;
+ }
return sprintf(buf, "%d\n", tolerance);
}