Re: [PATCH 3/4] iio: ltr501: ltr501_read_ps(): add missing endianness conversion

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 10.06.2021 16:21:30, Andy Shevchenko wrote:
> On Thu, Jun 10, 2021 at 3:55 PM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
> >
> > From: Oliver Lang <Oliver.Lang@gossenmetrawatt.com>
> >
> > The PS ADC Channel data is spread over 2 registers in little-endian
> > form. This patch adds the missing endianness conversion.
> >
> > Fixes: 2690be905123 ("iio: Add Lite-On ltr501 ambient light / proximity sensor driver")
> > Signed-off-by: Oliver Lang <Oliver.Lang@gossenmetrawatt.com>
> > Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> > ---
> >  drivers/iio/light/ltr501.c | 16 ++++++----------
> >  1 file changed, 6 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
> > index 79898b72fe73..0e3f97ef3cdd 100644
> > --- a/drivers/iio/light/ltr501.c
> > +++ b/drivers/iio/light/ltr501.c
> > @@ -407,20 +407,16 @@ static int ltr501_read_als(const struct ltr501_data *data, __le16 buf[2])
> >                                 buf, 2 * sizeof(__le16));
> >  }
> >
> > -static int ltr501_read_ps(const struct ltr501_data *data)
> > +static int ltr501_read_ps(const struct ltr501_data *data, __le16 *buf)
> >  {
> > -       int ret, status;
> > +       int ret;
> >
> >         ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
> >         if (ret < 0)
> >                 return ret;
> >
> > -       ret = regmap_bulk_read(data->regmap, LTR501_PS_DATA,
> > -                              &status, 2);
> > -       if (ret < 0)
> > -               return ret;
> > -
> > -       return status;
> > +       return regmap_bulk_read(data->regmap, LTR501_PS_DATA,
> > +                               buf, sizeof(__le16));
> 
> This is slightly weird since we pass a pointer to a buffer of one
> element (buffer can be longer, but here it's always one element is in
> use). The original code is better (initially). Also making caller to
> do endiannes conversion each time is not good.

We decided to implement the same semantics as ltr501_read_als(), where
the caller does the endianness conversion. I'll change the code and send
a v2 (with a proper cover letter subject :))

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
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