On Fri, Sep 25, 2020 at 12:35:49PM +0300, Andy Shevchenko wrote:
> On Thu, Sep 24, 2020 at 6:07 AM Kent Gibson <warthog...@gmail.com> wrote:
> > On Wed, Sep 23, 2020 at 06:47:28PM +0300, Andy Shevchenko wrote:
> > > On Tue, Sep 22, 2020 at 5:35 AM Kent Gibson <warthog...@gmail.com> wrote:
>
> ...
>
> > Also, this code is drawn from lineevent_irq_thread(), which is ordered
> > this way.
>
> Negative conditionals are slightly harder to read.
>
> ...
>
> > > > + if (!line->timestamp_ns) {
> > > > + le.timestamp_ns = ktime_get_ns();
> > > > + if (lr->num_lines != 1)
> > > > + line->req_seqno = atomic_inc_return(&lr->seqno);
> > > > + } else {
> > > > + le.timestamp_ns = line->timestamp_ns;
> > > > > + }
> > >
> > > Ditto.
> >
> > Firstly, drawn from lineevent_irq_thread() which is structured this way.
> >
> > In this case the comment relates to the condition being true, so
> > re-ordering the if/else would be confusing - unless the comment were
> > moved into the corresponding body??
>
> Yes.
>
Does that mean I should re-order and move the comment into the body?
That would work for me - the normal case is line->timestamp_ns being
set.
> ...
>
> > > > + irq = gpiod_to_irq(line->desc);
> > > > + if (irq <= 0)
> > > > + return -ENODEV;
> > >
> > > So, you mean this is part of ABI. Can we return more appropriate code,
> > > because getting no IRQ doesn't mean we don't have a device.
> > > Also does 0 case have the same meaning?
> >
> > Firstly, this code is drawn from lineevent_create(), so any changes
> > here should be considered for there as well - though this may
> > constitute an ABI change??
>
> For v1 probably, for v2 we are free to fix this.
>
> > I agree ENODEV doesn't seem right here. Are you ok with ENXIO?
>
> Yes.
>
Will do. And in the debounce patch as well.
> > From gpiod_to_irq():
> >
> > /* Zero means NO_IRQ */
> > if (!retirq)
> > return -ENXIO;
> >
> > so it can't even return a 0 :-| - we're just being cautious.
>
> I would drop = part then.
>
ok, but you'd better not come after me in a subsequent review for not
checking the 0 case!
Cheers,
Kent.
