Hi Biju,
On Mon, Aug 21, 2023 at 10:21 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > On Sun, Aug 20, 2023 at 7:12 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > wrote:
> > > Convert enum->pointer for data in the match tables, so that
> > > device_get_match_data() can do match against OF/ACPI/I2C tables, once
> > > i2c bus type match support added to it and it returns NULL for non-match.
> > >
> > > Therefore it is better to convert enum->pointer for data match and
> > > extend match support for both ID and OF tables using
> > > i2c_get_match_data() by adding struct sbs_data with flags variable and
> > > replacing flags->data in struct sbs_info.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> >
> > > --- a/drivers/power/supply/sbs-battery.c
> > > +++ b/drivers/power/supply/sbs-battery.c
> > > @@ -201,6 +201,10 @@ static const enum power_supply_property
> > > string_properties[] = {
> > >
> > > #define NR_STRING_BUFFERS ARRAY_SIZE(string_properties)
> > >
> > > +struct sbs_data {
> > > + u32 flags;
> > > +};
> >
> > Unless you plan to add more members to struct sbs_data, I see no point in
> > this patch: it only increases kernel size.
> >
> > The various "data" members in <foo>_id structures are intended to contain
> > either a pointer or a single integral value.
>
> The match data value for sbs_battery is 0. Here the API returns
> NULL for a non-match. That is the reason it is converted to pointer.
>
> So, we cannot differentiate actual matched data and error in this case.
If the driver's .probe() method is called, there must have been a
valid match, so i2c_get_match_data() will never return NULL due to
a non-match.
BTW, the driver does not check for a NULL return value from
*_get_match_data() anyway (and there is no reason to change this!).
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
