Re: [PATCH v3 3/7] irqchip: gic: Support hierarchy irq domain.

From: Marc Zyngier
Date: Mon Oct 13 2014 - 08:10:55 EST


This is a multi-part message in MIME format.On 13/10/14 11:43, Joe.C wrote:
> On Thu, 2014-10-09 at 17:59 +0100, Marc Zyngier wrote:
>> On 09/10/14 15:29, Joe.C wrote
>>> @@ -952,7 +988,11 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>>>
>>> gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
>>>
>>> - if (of_property_read_u32(node, "arm,routable-irqs",
>>> + if (IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) &&
>>> + of_find_property(node, "arm,irq-domain-hierarchy", NULL))
>>> + gic->domain = irq_domain_add_linear(node, gic_irqs,
>>> + &gic_irq_domain_hierarchy_ops, gic);
>>
>> I really think that looking for a property is the wrong thing to do. If
>> "node" is non-NULL, then we're pretty sure that we're initializing from
>> DT, and that a pure linear domain should be the right thing, leaving the
>> legacy stuff for the few non-DT platforms that are still around.
>>
>> Thanks,
>>
>> M.
>
> The only reason I introduce "arm,irq-domain-hierarchy" property is
> trying to keep original behavior when hierarchy irq domain is not used.
> Without this, when a board init GIC with DT, all driver will have to use
> devicetree. I'm not sure we want to break things like this.

I don't think we want to support a "middle of the road" setup, where the
GIC is probed by DT, but some devices have hardcoded interrupts.

> I will remove this and just use linear for all DT in my next version.

I came up with the attached patch, which allows me to boot my test
platform (together with the other fix I posted earlier).

Thanks,

M.
--
Jazz is not dead. It just smells funny...