Re: [PATCH] hwmon: gpio-fan: allow to stop FANs when CONFIG_PM is disabled

[Guenter Roeck]

On Mon, Feb 02, 2026 at 04:58:57PM +0100, Gabor Juhos wrote:
> When CONFIG_PM is disabled, the GPIO controlled FANs can't be stopped by
> using the sysfs attributes since commit 0d01110e6356 ("hwmon: (gpio-fan)
> Add regulator support").
> 
> Using either the 'pwm1' or the 'fan1_target' attribute fails the same way:
> 
>   $ echo 0 > /sys/class/hwmon/hwmon1/pwm1
>   ash: write error: Function not implemented
>   $ echo 0 > /sys/class/hwmon/hwmon1/fan1_target
>   ash: write error: Function not implemented
> 
> Both commands were working flawlessly before the mentioned commit.
> 
> The issue happens because pm_runtime_put_sync() returns with -ENOSYS
> when CONFIG_PM is disabled, and the set_fan_speed() function handles
> this as an error.
> 
> In order to restore the previous behaviour, change the error check in
> the set_fan_speed() function to ignore the -ENOSYS error code.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 0d01110e6356 ("hwmon: (gpio-fan) Add regulator support")
> Signed-off-by: Gabor Juhos <j4g8y7@xxxxxxxxx>

Applied.

Thanks,
Guenter