Re: [PATCH v1 1/1] hwmon: (isl28022) Don't check for specific errors when parsing properties

[Geert Uytterhoeven]

Hi Andy,

CC devicetree

On Thu, 19 Feb 2026 at 15:06, Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> Instead of checking for the specific error codes (that can be considered
> a layering violation to some extent) check for the property existence first
> and then either parse it, or apply a default value.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

Thanks for your patch!

> --- a/drivers/hwmon/isl28022.c
> +++ b/drivers/hwmon/isl28022.c
> @@ -337,21 +337,28 @@ DEFINE_SHOW_ATTRIBUTE(shunt_voltage);
>   */
>  static int isl28022_read_properties(struct device *dev, struct isl28022_data *data)
>  {
> +       const char *propname;
>         u32 val;
>         int err;
>
> -       err = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
> -       if (err == -EINVAL)
> +       propname = "shunt-resistor-micro-ohms";
> +       if (device_property_present(dev, propname)) {
> +               err = device_property_read_u32(dev, propname, &val);
> +               if (err)
> +                       return err;
> +       } else {
>                 val = 10000;
> -       else if (err < 0)
> -               return err;
> +       }
>         data->shunt = val;

IIRC, we have removed superfluous presence checks all over the tree
during the past few years? E.g. of_property_read_*() is documented to
return -EINVAL if a property does not exist.
So this patch looks like a step back to me...

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