[PATCH v6] irq: add irq_domain support to generic-chip
Shawn Guo
shawn.guo at linaro.org
Thu Feb 9 18:36:04 EST 2012
On Thu, Feb 09, 2012 at 04:31:04PM -0600, Rob Herring wrote:
> On 02/09/2012 01:48 PM, Shawn Guo wrote:
> > On Wed, Feb 08, 2012 at 04:55:22PM -0600, Rob Herring wrote:
...
> >> + if (node)
> >> + d = irq_domain_add_linear(node, hwirq_cnt,
> >> + &irq_gc_irq_domain_ops, gc);
> >> + else
> >> + d = irq_domain_add_legacy(node, hwirq_cnt, irq_base, 0,
> >> + &irq_gc_irq_domain_ops, gc);
> >> +
> > I do not think it's good to make this decision based on whether it's
> > dt or non-dt case. That said, it's fairly valid and actually
> > encouraged that non-dt users use linear domain too, and also the
> > irqdomain core has no limit on dt users to use legacy domain. Instead,
> > it's much more reasonable to make this decision based on if irq_base,
> > something like you did in your v3 patch.
> >
> >
> > - if (node)
> > + if ((int) irq_base < 0)
> >
>
> Really, we want to discourage/limit the use of legacy domains.
That's exactly the point I want to make. Your current code forces
non-dt users to use legacy domain, since they always get 'node' as
NULL. We should check irq_base, so that non-dt users can chose to
use linear domain by passing irq_base as something like -1.
Regards,
Shawn
> This is
> only used for ISA irqs on powerpc. Unfortunately, there's not really a
> way to use linear domains for non-DT ATM. But maybe we can fix that.
>
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