[PATCH 2/2] Fix irq_alloc_host() reference counting and callers

[Paul Mackerras]

Michael Ellerman writes:

> When I changed irq_alloc_host() to take an of_node
> (52964f87c64e6c6ea671b5bf3030fb1494090a48: "Add an
> optional device_node pointer to the irq_host"),
> I botched the reference counting semantics.
> 
> Stephen pointed out that it's irq_alloc_host()'s
> business if it needs to take an additional reference
> to the device_node, the caller shouldn't need to care.
> To make that clean we also need a free routine, so
> the caller doesn't have to deal with dropping the
> reference.
> 
> Luckily we now have an irq_free_host() where we can
> drop the reference - so we can make the reference
> counting internal to irq_alloc_host()/irq_free_host().

Is this needed for 2.6.26?  What's the worst possible effect of this
bug?

Paul.