Re: [PATCH 1/1] Input: ab8500-ponkey: Make the distinction betweenDT and non-DT boots

From: Lee Jones
Date: Wed Aug 08 2012 - 04:04:35 EST


On Tue, Aug 07, 2012 at 06:03:34PM +0100, Mark Brown wrote:
> On Tue, Aug 07, 2012 at 06:01:30PM +0100, Lee Jones wrote:
>
> > Okay, so I've just spent a small amount of time looking at this. I think
> > the best place for this would be in *_get_virq(), using the same logic that
> > selected a *_legacy or *_linear domain in the first place. The only thing
> > the domain can test for is the 'type' of domain and the requested IRQ. This
> > is where the issue lies. If a hwirq to virq conversion is requested, but a
> > virq is passed (which happens in the non-DT case) a WARN() is triggered
> > because the irq passed is bigger than first_irq + size. I think *_get_virq()
> > should ensure that only a hwirq is passed to irq_create_mapping().
>
> > Let me know if you had other ideas.
>
> I'd expect your driver to always pass a hwirq into _get_virq() here.

Okay, actually this isn't so easy. Currently we have:

During DT boot:
- No platform data is passed, hence no IRQ base for AB8500 is either
- No IRQ base means we register a Linear IRQ Domain
- MFD sees there is no base and leaves the IRQ resource as a hwirq
- AB8500 child devices use *_get_virq() to convert the hwirq to a virq

During non-DT boot:
- Platform data is passed, which contains an IRQ base
- If an IRQ base is requested we use it to register a Legacy IRQ Domain
- MFD adds the IRQ base to the hwirq and registers it as a virq
- AB8500 child devices use *_get_virq() to convert virq to virq - *ERROR*

I guess my suggestion falls-back to placing logic in *_get_virq() to only
call irq_create_mapping() when when !ab8500->irq_base.

--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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