From mboxrd@z Thu Jan  1 00:00:00 1970
From: tglx@linutronix.de (Thomas Gleixner)
Date: Tue, 17 Mar 2009 00:52:31 +0100 (CET)
Subject: [ltt-dev] [PATCH] kernel/irq/handle.c fix kstat_irqs_cpu and
 irq_to_desc symbols
In-Reply-To: <20090316231122.GA18113@Krystal>
References: <20090316182227.GA2444@yoda.jdub.homelinux.org>
	<20090316194459.GD11878@Krystal>
	<20090316200115.GA22538@yoda.jdub.homelinux.org>
	<20090316202500.GA13872@Krystal>
	<20090316205829.GB22538@yoda.jdub.homelinux.org>
	<20090316215337.GB15119@Krystal>
	<20090316220518.GD22538@yoda.jdub.homelinux.org>
	<20090316231122.GA18113@Krystal>
Message-ID: <alpine.LFD.2.00.0903170048120.29264@localhost.localdomain>

On Mon, 16 Mar 2009, Mathieu Desnoyers wrote:
> Mathieu :
> 
> This build problem was exhibited because of the added
> EXPORT_SYMBOL(irq_to_desc) in the LTTng tree, but only on powerpc.
> 
> Applies on 2.6.29-rc8.

Applies, but that does not make it a useful patch per se.

2.6.29-rc8/include/linux/irqnr.h has (condensed excerpt):

#ifndef CONFIG_GENERIC_HARDIRQS
#define nr_irqs                 NR_IRQS
#define irq_to_desc(irq)        (&irq_desc[irq])
#else
extern int nr_irqs;
extern struct irq_desc *irq_to_desc(unsigned int irq);
#endif  /* CONFIG_GENERIC_HARDIRQS */

And this adds right below of the #endif:
 
> +++ linux-2.6-lttng/include/linux/irqnr.h	2009-03-16 18:40:01.000000000 -0400
> @@ -38,6 +38,10 @@ extern struct irq_desc *irq_to_desc(unsi
>  
>  #endif /* CONFIG_GENERIC_HARDIRQS */
>  
> +extern int nr_irqs;
> +struct irq_desc;
> +extern struct irq_desc *irq_to_desc(unsigned int irq);
> +

Is this a contribution to the "most useless patch of the week"
contest ?

You have my vote.

    tglx