On Fri, Oct 21, 2022 at 10:10:08AM +0300, Matti Vaittinen wrote:
> On 10/20/22 17:34, Andy Shevchenko wrote:
> > On Thu, Oct 20, 2022 at 02:37:15PM +0300, Matti Vaittinen wrote:
...
> > > + ret = regmap_bulk_read(data->regmap, chan->address, &data->buffer,
> > > + sizeof(__le16));
> > > + if (ret)
> > > + return ret;
> > > +
> > > + *val = le16_to_cpu(data->buffer[0]);
> >
> > 'p'-variant of the above would look better
> >
> > *val = le16_to_cpup(data->buffer);
> >
> > since it will be the same as above address without any additional arithmetics.
> >
>
> I guess there is no significant performance difference? To my eye the
> le16_to_cpu(data->buffer[0]) is much more clear. I see right from the call
> that we have an array here and use the first member. If there is no obvious
> technical merit for using le16_to_cpup(data->buffer) over
> le16_to_cpu(data->buffer[0]), then I do really prefer the latter for
> clarity.
Then you probably wanted to have &data->buffer[0] as a parameter to
regmap_bulk_read()?
...
> > > + if (data->trigger_enabled) {
> > > + iio_trigger_poll_chained(data->trig);
> > > + ret = IRQ_HANDLED;
> > > + }
> > > +
> > > + if (data->state & KX022A_STATE_FIFO) {
> >
> > > + ret = __kx022a_fifo_flush(idev, KX022A_FIFO_LENGTH, true);
> > > + if (ret > 0)
> > > + ret = IRQ_HANDLED;
> >
> > I don't like it. Perhaps
> >
> > bool handled = false;
> > int ret;
> >
> > ...
> > ret = ...
> > if (ret > 0)
> > handled = true;
> > ...
> >
> > return IRQ_RETVAL(handled);
>
> I don't see the benefit of adding another variable 'handled'.
> If I understand correctly, it just introduces one extra 'if' in IRQ thread
> handling while hiding the return value in IRQ_RETVAL() - macro.
>
> I do like seeing the IRQ_NONE being returned by default and IRQ_HANDLED only
> when "handlers" are successfully executed. Adding extra variable just
> obfuscates this (from my eyes) while adding also the additional 'if'.
You assigning semantically different values to the same variable inside the
function.
--
With Best Regards,
Andy Shevchenko
