* Please revert commit dc9372808412edbc653a675a526c2ee6c0c14a91
@ 2011-11-22 22:11 Benjamin Herrenschmidt
2011-11-22 22:43 ` Grant Likely
0 siblings, 1 reply; 3+ messages in thread
From: Benjamin Herrenschmidt @ 2011-11-22 22:11 UTC (permalink / raw)
To: Linus Torvalds
Cc: devicetree-discuss, linuxppc-dev, Tanmay Inamdar, Rob Herring
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.
Cheers,
Ben.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Please revert commit dc9372808412edbc653a675a526c2ee6c0c14a91
2011-11-22 22:11 Please revert commit dc9372808412edbc653a675a526c2ee6c0c14a91 Benjamin Herrenschmidt
@ 2011-11-22 22:43 ` Grant Likely
2011-11-22 23:36 ` Rob Herring
0 siblings, 1 reply; 3+ messages in thread
From: Grant Likely @ 2011-11-22 22:43 UTC (permalink / raw)
To: Benjamin Herrenschmidt
Cc: linuxppc-dev, devicetree-discuss, Linus Torvalds, Tanmay Inamdar,
Rob Herring
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.
g.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Please revert commit dc9372808412edbc653a675a526c2ee6c0c14a91
2011-11-22 22:43 ` Grant Likely
@ 2011-11-22 23:36 ` Rob Herring
0 siblings, 0 replies; 3+ messages in thread
From: Rob Herring @ 2011-11-22 23:36 UTC (permalink / raw)
To: Grant Likely
Cc: devicetree-discuss, linuxppc-dev, Rob Herring, Tanmay Inamdar,
Linus Torvalds
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
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-11-22 22:11 Please revert commit dc9372808412edbc653a675a526c2ee6c0c14a91 Benjamin Herrenschmidt
2011-11-22 22:43 ` Grant Likely
2011-11-22 23:36 ` Rob Herring
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