[PATCH 2/2] gpio/tegra: Dynamically allocate IRQ base, and support DT

[Stephen Warren]

Jamie Iles wrote at Thursday, December 01, 2011 9:55 AM:
> On Thu, Dec 01, 2011 at 08:52:49AM -0800, Stephen Warren wrote:
> > Jamie Iles wrote at Thursday, December 01, 2011 7:11 AM:
> > > On Thu, Dec 01, 2011 at 07:42:57AM -0600, Rob Herring wrote:
> > > > On 11/30/2011 06:45 PM, Stephen Warren wrote:
...
> > > > > +	irq_domain.irq_base = irq_alloc_descs(-1, 0, TEGRA_NR_GPIOS, 0);
> > > > > +	if (irq_domain.irq_base < 0) {
> > > > > +		dev_err(&pdev->dev, "Couldn't allocate IRQ numbers\n");
> > > > > +		return -ENODEV;
> > > > > +	}
> > > > > +	irq_domain.nr_irq = TEGRA_NR_GPIOS;
> > > > > +	irq_domain.ops = &irq_domain_ops;
> > > >
> > > > Why don't you just use irq_domain_simple_ops?
> > >
> > > This would need the patch I posted earlier
> > > (https://lkml.org/lkml/2011/12/1/109) so they can work for the
> > > !CONFIG_OF case ;-)
> >
> > Part of my reasoning was that simple_ops appeared to be intended for
> > DT-based controllers; is it safe to use those ops for a controller that
> > wasn't instantiated from DT? I know that right now, the only op in that
> > structure is dt_translate, and that won't ever be called for the non-DT
> > case, but is there a guarantee that more functions won't be added to
> > the simple ops, and that they won't assume DT is in use, and fail if
> > not?
> >
> > If these are safe to use in the non-DT case, then yet I could build off
> > Jamie's patch, although managing the dependencies might be awkward.
> 
> Yes, it's absolutely fine to use it just that irq_simple_ops isn't
> currently exported unless you have CONFIG_OF_IRQ set so you'd get an
> undefined reference for !CONFIG_OF at the moment.

OK, sounds good.

So, I think we have a few options:
1) Merge my change as-is, and simplify it later once your patch is in.
2) Put your change in a branch, and merge it into both its usual place,
and the Tegra/ARM branches, so I can rebase my patch on top of it.
3) Have the usual maintainer ack it (I see Rob already did, but I think
Thomas is the maintainer here right?) and just put both patches into the
Tegra/ARM tree. This of course means non-Tegra branches have to wait for
it rather than the other way around.

(1) seems simplest, but (2) is probably doable. Thomas?

-- 
nvpublic