[PATCH] hwmon: (gsc-hwmon) fix fan pwm setpoint show functions

[PATCH] hwmon: (gsc-hwmon) fix fan pwm setpoint show functions

[Tim Harvey]

The Linux hwmon sysfs API values for pwmX_auto_pointY_pwm represent an
integer value between 0 (0%) to 255 (100%) and the pwmX_auto_pointY_temp
represent millidegrees Celcius.

Commit a6d80df47ee2 ("hwmon: (gsc-hwmon) fix fan pwm temperature
scaling") properly addressed the incorrect scaling in the
pwm_auto_point_temp_store implementation but erroneously scaled
the pwm_auto_point_pwm_show (pwm value) instead of the
pwm_auto_point_temp_show (temp value) resulting in:
 # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_pwm
 25500
 # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_temp
 4500

Fix the scaling of these attributes:
 # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_pwm
 255
 # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_temp
 45000

Fixes: a6d80df47ee2 ("hwmon: (gsc-hwmon) fix fan pwm temperature scaling")
Cc: stable@vger.kernel.org
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
 drivers/hwmon/gsc-hwmon.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/gsc-hwmon.c b/drivers/hwmon/gsc-hwmon.c
index 0f9af82cebec..105b9f9dbec3 100644
--- a/drivers/hwmon/gsc-hwmon.c
+++ b/drivers/hwmon/gsc-hwmon.c
@@ -64,7 +64,7 @@ static ssize_t pwm_auto_point_temp_show(struct device *dev,
 		return ret;
 
 	ret = regs[0] | regs[1] << 8;
-	return sprintf(buf, "%d\n", ret * 10);
+	return sprintf(buf, "%d\n", ret * 100);
 }
 
 static ssize_t pwm_auto_point_temp_store(struct device *dev,
@@ -99,7 +99,7 @@ static ssize_t pwm_auto_point_pwm_show(struct device *dev,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 
-	return sprintf(buf, "%d\n", 255 * (50 + (attr->index * 10)));
+	return sprintf(buf, "%d\n", 255 * (50 + (attr->index * 10)) / 100);
 }
 
 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point1_pwm, pwm_auto_point_pwm, 0);
-- 
2.34.1

Re: [PATCH] hwmon: (gsc-hwmon) fix fan pwm setpoint show functions

[Guenter Roeck]

On Fri, Jul 18, 2025 at 01:02:59PM -0700, Tim Harvey wrote:
> The Linux hwmon sysfs API values for pwmX_auto_pointY_pwm represent an
> integer value between 0 (0%) to 255 (100%) and the pwmX_auto_pointY_temp
> represent millidegrees Celcius.
> 
> Commit a6d80df47ee2 ("hwmon: (gsc-hwmon) fix fan pwm temperature
> scaling") properly addressed the incorrect scaling in the
> pwm_auto_point_temp_store implementation but erroneously scaled
> the pwm_auto_point_pwm_show (pwm value) instead of the
> pwm_auto_point_temp_show (temp value) resulting in:
>  # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_pwm
>  25500
>  # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_temp
>  4500
> 
> Fix the scaling of these attributes:
>  # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_pwm
>  255
>  # cat /sys/class/hwmon/hwmon0/pwm1_auto_point6_temp
>  45000
> 
> Fixes: a6d80df47ee2 ("hwmon: (gsc-hwmon) fix fan pwm temperature scaling")
> Cc: stable@vger.kernel.org
> Signed-off-by: Tim Harvey <tharvey@gateworks.com>

Applied.

Thanks,
Guenter