RE: [PATCH v4 5/6] iio: imu: Add support for adis16475

["Sa, Nuno" <Nuno.Sa@analog.com>]

> From: linux-iio-owner@vger.kernel.org <linux-iio-owner@vger.kernel.org>
> On Behalf Of Andy Shevchenko
> Sent: Dienstag, 7. April 2020 11:55
> To: Sa, Nuno <Nuno.Sa@analog.com>
> Cc: linux-iio <linux-iio@vger.kernel.org>; devicetree
> <devicetree@vger.kernel.org>; Jonathan Cameron <jic23@kernel.org>;
> Hartmut Knaack <knaack.h@gmx.de>; Lars-Peter Clausen
> <lars@metafoo.de>; Peter Meerwald-Stadler <pmeerw@pmeerw.net>; Rob
> Herring <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>;
> Ardelean, Alexandru <alexandru.Ardelean@analog.com>; Hennerich,
> Michael <Michael.Hennerich@analog.com>
> Subject: Re: [PATCH v4 5/6] iio: imu: Add support for adis16475
> 
> On Tue, Apr 7, 2020 at 12:26 PM Sa, Nuno <Nuno.Sa@analog.com> wrote:
> >
> > > From: Andy Shevchenko <andy.shevchenko@gmail.com>
> > > Sent: Dienstag, 7. April 2020 11:19
> > > To: Sa, Nuno <Nuno.Sa@analog.com>
> > > Cc: linux-iio <linux-iio@vger.kernel.org>; devicetree
> > > <devicetree@vger.kernel.org>; Jonathan Cameron <jic23@kernel.org>;
> > > Hartmut Knaack <knaack.h@gmx.de>; Lars-Peter Clausen
> > > <lars@metafoo.de>; Peter Meerwald-Stadler <pmeerw@pmeerw.net>;
> Rob
> > > Herring <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>;
> > > Ardelean, Alexandru <alexandru.Ardelean@analog.com>; Hennerich,
> > > Michael <Michael.Hennerich@analog.com>
> > > Subject: Re: [PATCH v4 5/6] iio: imu: Add support for adis16475
> 
> ...
> 
> > > > > > +       for_each_set_bit(bit, indio_dev->active_scan_mask,
> > > > > > +                        indio_dev->masklength) {
> > > > >
> > > > > One line?
> > > > >
> > > >
> > > > It goes beyond 80 col limit... I know I could initialize these to some local
> > > const but...
> > >
> > > That's why question mark is there.
> > > Nonetheless, if it ~2-3 characters more, I would leave it on one line
> anyway.
> > >
> > > JFYI: readability has a priority over 80 limit.
> > >
> >
> > Thanks! I would say it also depends on the maintainer (not sure)? Some are
> more
> > strict about checkpatch...
> > Btw, the line will have 84 if one liner...
> 
> Let's leave it to maintainer then.
> 
> > > > > > +       }
> 
> ...
> 
> > > > > > +       irq_type = irqd_get_trigger_type(desc);
> > > > > > +       if (irq_type == IRQF_TRIGGER_RISING) {
> > >
> > > > > > +               polarity = 1;
> > >
> > > For the sake of consistency I would assign irq_flag here as well.
> > >
> >
> > The library will do it by default, But that's me using "inside" info... or maybe
> if
> > I document that in patch 2 (the struct kernel docs) we would not really
> need to
> > assign it here?
> 
> I see now. From my point of view the library here does an ill turn
> because it hides some details which driver needs to do anyway.
> I prefer explicit over implicit at least here.
> 

Let's explicitly assign the irq_flag then...

> I would say okay, if there is no such code (like below) would be
> present in the driver.

Now that I think about, this is actually code that, probably, could go inside the
library since this is pretty standard for this kind of devices. Anyways, that's
another story...

- Nuno Sá
> > > > > > +       } else if (irq_type == IRQF_TRIGGER_FALLING) {
> > > > > > +               polarity = 0;
> > > > > > +               st->adis.irq_flag = IRQF_TRIGGER_FALLING;
> > > > > > +       } else {
> > > > > > +               dev_err(&spi->dev, "Invalid interrupt type 0x%x
> specified\n",
> > > > > > +                       irq_type);
> > > > > > +               return -EINVAL;
> > > > > > +       }
> > > > >
> > > > > Here is the problem. You got type, but you compare it to flags. It's
> > > > > not correct.
> > > > > Although values are the same, the meaning is different.
> > > > >
> > > >
> > > > Hmm, thanks! Honestly, this was copy paste from adis16480 and I never
> > > realized this. I will
> > > > use IRQ_TYPE_EDGE_RISING and IRQ_TYPE_EDGE_FALLING.
> 
> --
> With Best Regards,
> Andy Shevchenko