From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [PATCH v5 06/27] irq_domain/powerpc: eliminate irq_map; use
 irq_alloc_desc() instead
Date: Sat, 07 Apr 2012 09:37:50 +1000
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To: Andreas Schwab <schwab@linux-m68k.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>, Grant Likely <grant.likely@secretlab.ca>, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, Milton Miller <miltonm@bga.com>, Rob Herring <rob.herring@calxeda.com>, Thomas Gleixner <tglx@linutronix.de>, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org
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On Fri, 2012-04-06 at 13:51 +0200, Andreas Schwab wrote:
> Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:
> 
> > Ok. Doesn't matter anyway, this shouldn't be the problem in this
> > specific case. IE. we shouldn't be setting that interrupt to NONE.
> 
> After removinge the call to irq_set_irq_type in mpic_host_map the irq
> problem disappears.
> 
> Instead of the irq_set_irq_type(,NONE) calls from mpic_host_map I see
> corresponding irq_set_irq_type(,LEVEL_LOW) calls now.

It's arguable that this irq_set_irq_type(,NONE) shouln't be there but
still ... it's been around for ever and things worked :-) So something
-else- is causing the problem and I'd like to understand what exactly.

(When I say arguable, I do mean it. There are some reasons to keep it
even if we agree that it's not "setting a default" but marking the
interrupt as somewhat disabled as Russell wants, that's fine with me, an
MPIC external interrupt should -always- have a proper type set before
being used).

First we need to fix that business with NR_IRQS/nr_irqs everywhere, then
if the problem persists, check why we aren't calling the proper
irq_set_irq_type() after the mapping is established (we should be).

Cheers,
Ben.