Re: [PATCH v6 3/5] iio: adc: ad7949: add vref selection support

From: Andy Shevchenko
Date: Mon Aug 16 2021 - 08:49:11 EST


On Mon, Aug 16, 2021 at 3:39 PM Liam Beguin <liambeguin@xxxxxxxxx> wrote:
> On Mon Aug 16, 2021 at 4:04 AM EDT, Andy Shevchenko wrote:
> > On Mon, Aug 16, 2021 at 12:35 AM Liam Beguin <liambeguin@xxxxxxxxx>
> > wrote:

...

> > > + tmp = 4096000;
> > > + ret = device_property_read_u32(dev, "adi,internal-ref-microvolt", &tmp);
> >
> > > + if (ret < 0 && ret != -EINVAL) {
>
> Hi Andy,
>
> >
> > What does this check (second part) is supposed to mean?
> > The first part will make it mandatory, is it the goal?
> >
>
> device_property_read_u32() will return -EINVAL if the property isn't
> found in the devicetree.
>
> This checks for errors when the property is defined while keeping it
> optional.

Don't assign and don't check the error code of the API. As simply as that.

> > > + dev_err(dev, "invalid value for adi,internal-ref-microvolt\n");
> > > + return ret;
> > > + }


--
With Best Regards,
Andy Shevchenko