[PATCH v5 06/27] irq_domain/powerpc: eliminate irq_map; use irq_alloc_desc() instead

[Thomas Gleixner]

On Tue, 3 Apr 2012, Benjamin Herrenschmidt wrote:

> On Mon, 2012-04-02 at 22:52 +0200, Thomas Gleixner wrote:
> > > When I revert a09b659cd68c10ec6a30cb91ebd2c327fcd5bfe5 ("genirq: Fix
> > > long-term regression in genirq irq_set_irq_type() handling") on top
> > of
> > > 3.4-rc1 the sata irq errors disappear, but I see a lot of spurious
> > 
> > Hmm. Which irq chip is handling the interrupt for that sata irq ?
> 
> MPIC. The irq is a PCI IRQ, and so should be level-low, it should have
> been mapped by the PCI code using the of_* calls.

So it's covered by this section:

mpic_set_irq_type()

        if (flow_type == IRQ_TYPE_NONE)
                if (mpic->senses && src < mpic->senses_count)
                        flow_type = mpic->senses[src];
        if (flow_type == IRQ_TYPE_NONE)
                flow_type = IRQ_TYPE_LEVEL_LOW;

And with IRQ_TYPE_NONE this is always going to end up with
IRQ_TYPE_LEVEL_LOW simply because the only function which might set
mpic->senses is mpic_set_default_senses(). And this function does not
have a single caller .....

/me scratches head