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

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 12 Apr 2012 07:37:28 +1000

On Wed, 2012-04-11 at 14:57 -0600, Grant Likely wrote:
> 
> Yeah, I've got a different way to fix it though.  There is exactly one
> user of irq_virq_count in-tree right now: PS3.  Also, irq_virq_count
> is only useful for the NOMAP mapping.  So, instead of having a single
> global irq_virq_count values, I've dropped it entirely and added a
> max_irq argument to irq_domain_add_nomap().  That makes it a property
> of an individual nomap irq domain instead of a global system settting.
> 
> Hopefully I'll have a draft patch ready today. 

That works for me. I'll send patches for cleanup MPIC as well.

One thing tho (Thomas, Russell) is that I like using set_irq_trigger to
establish the "defaults" in mpic, ie, it does the descriptor locking
etc... for me, I'd rather avoid open coding all of that. What I need is
a "variant" that doesn't actually change the trigger but instead
initializes the irq_desc with whatever settings the HW currently has
(ie, I need to make sure things are properly in sync) though other
implementations may want to use that for defaults.

Any objection to defining something like IRQ_TYPE_DEFAULT ?

I was thinking about making it equal to IRQ_TYPE_SENSE_MASK since that
can obviously not be a valid trigger value and is distinct from
IRQ_TYPE_NONE.

Cheers,
Ben.