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

[Alan <alan@lxorguk.ukuu.org.uk>]

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;
 }