Tested with the following script and values
---

{
  # Access hwmon
  cd /sys/class/hwmon/hwmon1/

  # Set to 1 => 82
  echo -n ' [TEST] Set to 1 : '
  echo '1' >./fan1_max
  cat ./fan1_max

  # Set to 1234 => 1234
  echo -n ' [TEST] Set to 1234 : '
  echo '1234' >./fan1_max
  cat ./fan1_max

  # Reset to 0 => 0
  echo -n ' [TEST] Set to 0 : '
  echo '0' >./fan1_max
  cat ./fan1_max
}
---

Signed-off-by: Adrian DC <radian.dc@gmail.com>
---
 drivers/hwmon/adt7470.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
index dbee6926fa05..712bc41b4a0d 100644
--- a/drivers/hwmon/adt7470.c
+++ b/drivers/hwmon/adt7470.c
@@ -662,11 +662,15 @@ static int adt7470_fan_write(struct device *dev, u32 attr, int channel, long val
 	struct adt7470_data *data = dev_get_drvdata(dev);
 	int err;
 
-	if (val <= 0)
+	if (val < 0)
 		return -EINVAL;
 
-	val = FAN_RPM_TO_PERIOD(val);
-	val = clamp_val(val, 1, 65534);
+	if (val) {
+		val = FAN_RPM_TO_PERIOD(val);
+		val = clamp_val(val, 1, 65534);
+	} else {
+		val = FAN_PERIOD_INVALID;
+	}
 
 	switch (attr) {
 	case hwmon_fan_min:
-- 
2.43.0

On 1/5/25 11:55, Adrian DC wrote:
> Tested with the following script and values

The patch description is supposed to explain the reason for the changes,
not test results. Test results are useful, but only appropriate after "---".

Guenter

> ---
> 
> {
>    # Access hwmon
>    cd /sys/class/hwmon/hwmon1/
> 
>    # Set to 1 => 82
>    echo -n ' [TEST] Set to 1 : '
>    echo '1' >./fan1_max
>    cat ./fan1_max
> 
>    # Set to 1234 => 1234
>    echo -n ' [TEST] Set to 1234 : '
>    echo '1234' >./fan1_max
>    cat ./fan1_max
> 
>    # Reset to 0 => 0
>    echo -n ' [TEST] Set to 0 : '
>    echo '0' >./fan1_max
>    cat ./fan1_max
> }
> ---
> 
> Signed-off-by: Adrian DC <radian.dc@gmail.com>
> ---
>   drivers/hwmon/adt7470.c | 10 +++++++---
>   1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
> index dbee6926fa05..712bc41b4a0d 100644
> --- a/drivers/hwmon/adt7470.c
> +++ b/drivers/hwmon/adt7470.c
> @@ -662,11 +662,15 @@ static int adt7470_fan_write(struct device *dev, u32 attr, int channel, long val
>   	struct adt7470_data *data = dev_get_drvdata(dev);
>   	int err;
>   
> -	if (val <= 0)
> +	if (val < 0)
>   		return -EINVAL;
>   
> -	val = FAN_RPM_TO_PERIOD(val);
> -	val = clamp_val(val, 1, 65534);
> +	if (val) {
> +		val = FAN_RPM_TO_PERIOD(val);
> +		val = clamp_val(val, 1, 65534);
> +	} else {
> +		val = FAN_PERIOD_INVALID;
> +	}
>   
>   	switch (attr) {
>   	case hwmon_fan_min: