Re: Please revert commit dc9372808412edbc653a675a526c2ee6c0c14a91

[Rob Herring <robherring2@gmail.com>]

On 11/22/2011 04:43 PM, Grant Likely wrote:
> On Tue, Nov 22, 2011 at 3:11 PM, Benjamin Herrenschmidt
> <benh@kernel.crashing.org> wrote:
>> Hi Linus !
>>
>> Please, revert commit dc9372808412edbc653a675a526c2ee6c0c14a91
>>
>> "of/irq: of_irq_find_parent: check for parent equal to child"
>>
>> This breaks some powerpc platforms at least. The practice of having a
>> node provide an explicit "interrupt-parent" property pointing to itself
>> is an old trick that we've used in the past to allow a device-node to
>> have interrupts routed to different controllers.
>>
>> In that case, the node also contains an interrupt-map, so the node is
>> its own parent, the interrupt resolution hits the map, which then can
>> route each individual interrupt to a different parent.
> 
> Ah, nuts, yes that is broken then.  Yes, please revert the commit and
> Rob & I will come up with a better solution.
> 
> Rob, I think it can be done by explicitly checking for np ==
> desc->interrupt_parent in of_irq_init() instead of relying on
> of_irq_find_parent() returning NULL.

Okay. I'll prepare a patch to do that.

Rob