Re: [PATCH] kernel: shut up the IRQ mismatch messages (Re: wbsd: IRQ handler type mismatch)

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 6 Feb 2007 11:30:23 +0000
Alan <alan@lxorguk.ukuu.org.uk> wrote:

> On Mon, 05 Feb 2007 21:16:59 -0600
> Robert Hancock <hancockr@shaw.ca> wrote:
> 
> > I'm seeing this on bootup on my laptop with recent kernels (currently 
> > 2.6.20-rc6-mm3):
> 
> The problem is various drivers legally validly and sensibly try to claim
> IRQs but the kernel insists on vomiting forth a giant irrelevant
> debugging spew when the types clash.
> 
> Edit kernel/irq/manage.c go down to mismatch: in setup_irq() and ifdef
> out the if clause that checks for mismatches. It'll then just do the
> right thing and work sanely.
> 
> For the current -mm kernel this will do the trick (and moves it into
> shared irq debugging as in debug mode the info spew is useful). I've had
> a variant of this in my private tree for some time as I got fed up on the
> mess on boxes where old legacy IRQs get reused.
> 
> Signed-off-by: Alan Cox <alan@redhat.com>
> 
> --- linux.vanilla-2.6.20-rc6-mm3/kernel/irq/manage.c	2007-01-31 14:20:43.000000000 +0000
> +++ linux-2.6.20-rc6-mm3/kernel/irq/manage.c	2007-02-06 11:01:00.796928504 +0000
> @@ -372,12 +372,14 @@
>  	return 0;
>  
>  mismatch:
> +#ifdef CONFIG_DEBUG_SHIRQ
>  	if (!(new->flags & IRQF_PROBE_SHARED)) {
>  		printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
>  		if (old_name)
>  			printk(KERN_ERR "current handler: %s\n", old_name);
>  		dump_stack();
>  	}
> +#endif	
>  	spin_unlock_irqrestore(&desc->lock, flags);
>  	return -EBUSY;
>  }

hm, well, it's dependent upon dwmw2's
generate-a-spurious-irq-at-request_irq-time patch.  Do we want to merge
that?