From: Xing Tong Wu <xingtong.wu@xxxxxxxxxxx> [ Upstream commit 8b3800256abad20e91c2698607f9b28591407b19 ] 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 when attempting to set the fan speed in automatic mode. Signed-off-by: Xing Tong Wu <xingtong.wu@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20231121081604.2499-3-xingtong_wu@xxxxxxx Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/hwmon/nct6775-core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/hwmon/nct6775-core.c b/drivers/hwmon/nct6775-core.c index d928eb8ae5a3..92a49fafe2c0 100644 --- a/drivers/hwmon/nct6775-core.c +++ b/drivers/hwmon/nct6775-core.c @@ -2553,6 +2553,13 @@ store_pwm(struct device *dev, struct device_attribute *attr, const char *buf, int err; u16 reg; + /* + * The fan control mode should be set to manual if the user wants to adjust + * the fan speed. Otherwise, it will fail to set. + */ + if (index == 0 && data->pwm_enable[nr] > manual) + return -EBUSY; + err = kstrtoul(buf, 10, &val); if (err < 0) return err; -- 2.43.0
