From: Xing Tong Wu <xingtong.wu@xxxxxxxxxxx> Setting the fan speed is only valid in manual mode; it is not possible to set the fan's speed in automatic mode. Return error and show error message when attempting to set the fan speed in automatic mode. Signed-off-by: Xing Tong Wu <xingtong.wu@xxxxxxxxxxx> --- drivers/hwmon/nct6775-core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/hwmon/nct6775-core.c b/drivers/hwmon/nct6775-core.c index 575db6cb96e9..3fb9896c61ce 100644 --- a/drivers/hwmon/nct6775-core.c +++ b/drivers/hwmon/nct6775-core.c @@ -2551,6 +2551,14 @@ store_pwm(struct device *dev, struct device_attribute *attr, const char *buf, int err; u16 reg; + if (index == 0 && data->pwm_enable[nr] != manual) { + dev_err(dev, + "The pwm%d doesn't support manual fan speed control in automatic mode.\n", + nr + 1); + dev_err(dev, "Please set pwm%d_enable to manual mode.\n", nr + 1); + return -EOPNOTSUPP; + } + err = kstrtoul(buf, 10, &val); if (err < 0) return err; -- 2.25.1