[PATCH 4/7] hwmon: (it87) Ensure that pwm control cache is current before updating values

[Guenter Roeck <linux@roeck-us.net>]

If sensor attributes were never read, the pwm control data has not been
initiialized, which can cause wrong driver behavior. Ensure that cached
data is current before acting on it.

Cc: stable@vger.kernel.org # 4.4+
Reported-by: Kevin Folz <kfolz@evertz.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/it87.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index 11a28b233006..85918d8a747a 100644
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -1360,6 +1360,7 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
 		return -EINVAL;
 
 	mutex_lock(&data->update_lock);
+	it87_update_pwm_ctrl(data, nr);
 	if (has_newer_autopwm(data)) {
 		/*
 		 * If we are in automatic mode, the PWM duty cycle register
@@ -1472,6 +1473,7 @@ static ssize_t set_pwm_temp_map(struct device *dev,
 	}
 
 	mutex_lock(&data->update_lock);
+	it87_update_pwm_ctrl(data, nr);
 	data->pwm_temp_map[nr] = reg;
 	/*
 	 * If we are in automatic mode, write the temp mapping immediately;
-- 
2.7.4