Subject: [PATCH v2 4/7] ARM: pxa: add devicetree code for irq handling

From: [email-masked] (Daniel Mack)
Date: Mon, 30 Jul 2012 10:34:04 +0200

On 30.07.2012 10:31, Arnd Bergmann wrote:
> On Sunday 29 July 2012, Daniel Mack wrote:
>> Hmm, PXA25x (which does not feature IRQ priorities) shares a fair amount
>> of peripherals with other PXA series (which do have support for that). I
>> would much like to reflect that fact by inherhiting device nodes from
>> one dtsi to the other. Hence, if at all, we would need to have two cells
>> always, and just ignore the second argument on PXA25x.
> 
> But that can only work if the interrupt numbers are identical between PXA25x
> and the other SoCs. Are they?

Yes.

>> And I also wonder whether using the second spec value for a priority
>> wouldn't be somehow abusive? Isn't that considered to denote the trigger
>> flags in contexts of interrupt controllers? At least, that is what
>> irq_domain_xlate_twocell() assumes.
> 
> You would not use irq_domain_xlate_twocell in that scenario but provide your
> own, which is ok. Interpreting the second cell as the trigger flags is just
> a convenient default because it's the most common use for that.

I see. Don't know how much sense it makes to have that detail
configurable though. Haojian? And I think we can still change that
detail later.

Daniel