1 files changed, 32 insertions, 0 deletions

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index bbb0c7443b9b..1002befd87d5 100644
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -719,6 +719,32 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
         mutex_unlock(&data->update_lock);
         return count;
 }
+
+/* Returns 0 if OK, -EINVAL otherwise */
+static int check_trip_points(struct device *dev, int nr)
+{
+        const struct it87_data *data = dev_get_drvdata(dev);
+        int i, err = 0;
+
+        if (has_old_autopwm(data)) {
+                for (i = 0; i < 3; i++) {
+                        if (data->auto_temp[nr][i] > data->auto_temp[nr][i + 1])
+                                err = -EINVAL;
+                }
+                for (i = 0; i < 2; i++) {
+                        if (data->auto_pwm[nr][i] > data->auto_pwm[nr][i + 1])
+                                err = -EINVAL;
+                }
+        }
+
+        if (err) {
+                dev_err(dev, "Inconsistent trip points, not switching to "
+                        "automatic mode\n");
+                dev_err(dev, "Adjust the trip points and try again\n");
+        }
+        return err;
+}
+
 static ssize_t set_pwm_enable(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t count)
 {
@@ -731,6 +757,12 @@ static ssize_t set_pwm_enable(struct device *dev,
         if (strict_strtol(buf, 10, &val) < 0 || val < 0 || val > 2)
                 return -EINVAL;
 
+        /* Check trip points before switching to automatic mode */
+        if (val == 2) {
+                if (check_trip_points(dev, nr) < 0)
+                        return -EINVAL;
+        }
+
         mutex_lock(&data->update_lock);
 
         if (val == 0) {