Re: [PATCH v4 1/9] power: supply: sysfs: print single value in uevent for POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR

[Armin Wolf]

Am 24.11.24 um 18:55 schrieb Thomas Weißschuh:

> Nov 24, 2024 18:47:39 Armin Wolf <W_Armin@xxxxxx>:
>
> > Am 11.11.24 um 22:40 schrieb Thomas Weißschuh:
> >
> > > Currently an uevent contains the same string representation of a
> > > property as sysfs. However for POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR this
> > > is specially formatted to indicate all possible values.
> > > This doesn't make sense for uevents and complicates parsing.
> > > Instead only include the currently active value in uevents.
> > >
> > > As currently no in-tree driver uses POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR
> > > this change is not a problem.
> > > Soon the property will actually be used so fix the formatting before
> > > that happens.
> > AFAIK the cros-charge-behaviour driver does use POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR,
> > so we have to make sure that no userspace application uses this uevent information.
> It only does so after this series.
> Currently it uses the ad-hoc sysfs attributes which don't show up in uevent.
> (I'm the maintainer)

I see, in this case you can ignore my comment.

Thank,
Armin Wolf

> > Other than that:
> >
> > Reviewed-by: Armin Wolf <W_Armin@xxxxxx>
> Thanks!
>
> > > Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
> > > ---
> > >    drivers/power/supply/power_supply_sysfs.c | 20 ++++++++++++++++----
> > >    1 file changed, 16 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
> > > index 571de43fcca9827cf0fe3023e453defbf1eaec7d..a7351b9c8fe34a464a4e69b1a1a4a4179c1a4b4f 100644
> > > --- a/drivers/power/supply/power_supply_sysfs.c
> > > +++ b/drivers/power/supply/power_supply_sysfs.c
> > > @@ -268,9 +268,11 @@ static ssize_t power_supply_show_enum_with_available(
> > >      return count;
> > >    }
> > >
> > > -static ssize_t power_supply_show_property(struct device *dev,
> > > -                     struct device_attribute *attr,
> > > -                     char *buf) {
> > > +static ssize_t power_supply_format_property(struct device *dev,
> > > +                       bool uevent,
> > > +                       struct device_attribute *attr,
> > > +                       char *buf)
> > > +{
> > >      ssize_t ret;
> > >      struct power_supply *psy = dev_get_drvdata(dev);
> > >      const struct power_supply_attr *ps_attr = to_ps_attr(attr);
> > > @@ -303,6 +305,8 @@ static ssize_t power_supply_show_property(struct device *dev,
> > >                  psy->desc->usb_types, value.intval, buf);
> > >          break;
> > >      case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR:
> > > +       if (uevent) /* no possible values in uevents */
> > > +           goto default_format;
> > >          ret = power_supply_charge_behaviour_show(dev, psy->desc->charge_behaviours,
> > >                               value.intval, buf);
> > >          break;
> > > @@ -310,6 +314,7 @@ static ssize_t power_supply_show_property(struct device *dev,
> > >          ret = sysfs_emit(buf, "%s\n", value.strval);
> > >          break;
> > >      default:
> > > +default_format:
> > >          if (ps_attr->text_values_len > 0 &&
> > >                  value.intval < ps_attr->text_values_len && value.intval >= 0) {
> > >              ret = sysfs_emit(buf, "%s\n", ps_attr->text_values[value.intval]);
> > > @@ -321,6 +326,13 @@ static ssize_t power_supply_show_property(struct device *dev,
> > >      return ret;
> > >    }
> > >
> > > +static ssize_t power_supply_show_property(struct device *dev,
> > > +                     struct device_attribute *attr,
> > > +                     char *buf)
> > > +{
> > > +   return power_supply_format_property(dev, false, attr, buf);
> > > +}
> > > +
> > >    static ssize_t power_supply_store_property(struct device *dev,
> > >                         struct device_attribute *attr,
> > >                         const char *buf, size_t count) {
> > > @@ -437,7 +449,7 @@ static int add_prop_uevent(const struct device *dev, struct kobj_uevent_env *env
> > >      pwr_attr = &power_supply_attrs[prop];
> > >      dev_attr = &pwr_attr->dev_attr;
> > >
> > > -   ret = power_supply_show_property((struct device *)dev, dev_attr, prop_buf);
> > > +   ret = power_supply_format_property((struct device *)dev, true, dev_attr, prop_buf);
> > >      if (ret == -ENODEV || ret == -ENODATA) {
> > >          /*
> > >           * When a battery is absent, we expect -ENODEV. Don't abort;