Re: [PATCH] platform/x86: asus-wmi: do not enforce a battery charge threshold

[Antheas Kapenekakis]

On Wed, 4 Mar 2026 at 14:26, Denis Benato <denis.benato@xxxxxxxxx> wrote:
>
> Users are complaining for the battery limit being reset at 100% during
> the boot process while the general consensus appears to not apply
> unsolecited hardware changes, therefore stop resetting the battery

*unsolicited. But I would rephrase to using this causes the device to
reset its limits on boot, which might have been set by e.g. windows so
if userspace is not aware to restore them, this causes a functionality
degradation. This is the case with the current implementation by KDE.

> charge limit at boot and return -ENODATA on charge_end_threshold to
> signal for an unknown limit.
>
> Suggested-by: Antheas Kapenekakis <lkml@xxxxxxxxxxx>
> Suggested-by: Derek J. Clark <derekjohn.clark@xxxxxxxxx>
> Signed-off-by: Denis Benato <denis.benato@xxxxxxxxx>
> ---
>  drivers/platform/x86/asus-wmi.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 6ba49bd375df..dc330a8ee2f2 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -1557,7 +1557,10 @@ static ssize_t charge_control_end_threshold_show(struct device *device,
>                                                  struct device_attribute *attr,
>                                                  char *buf)
>  {
> -       return sysfs_emit(buf, "%d\n", charge_end_threshold);
> +       if ((charge_end_threshold >= 0) && (charge_end_threshold <= 100))
> +               return sysfs_emit(buf, "%d\n", charge_end_threshold);
> +
> +       return -ENODATA;

Please verify this does not cause KDE to display a warning and block
modifying the energy consumption. If it does as has been my
experience, communicate with KDE devs or Gnome (if it has a similar
issue) and block this from merging until there is a solution from
their side.

Returning an error from this function when there is proper function is
a slight ABI change compared to current drivers that implement this
method.

Thanks,
Antheas

>  }
>
>  static DEVICE_ATTR_RW(charge_control_end_threshold);
> @@ -1580,11 +1583,11 @@ static int asus_wmi_battery_add(struct power_supply *battery, struct acpi_batter
>                 return -ENODEV;
>
>         /* The charge threshold is only reset when the system is power cycled,
> -        * and we can't get the current threshold so let set it to 100% when
> -        * a battery is added.
> +        * and we can't read the current threshold, however the majority of
> +        * platforms retains it, therefore signal the threshold as unknown
> +        * until user explicitly sets it to a new value.
>          */
> -       asus_wmi_set_devstate(ASUS_WMI_DEVID_RSOC, 100, NULL);
> -       charge_end_threshold = 100;
> +       charge_end_threshold = -1;
>
>         return 0;
>  }
> --
> 2.53.0
>
>