[PATCH] powerpc: warn on spurious irq events (but ratelimited)

[Paul Gortmaker]

It might be worth warning on spurious IRQ events; they might
point someone at a bogus DTS value or similar.

But ratelimit them to ensure we aren't too spammy about it.

Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: linuxppc-dev at lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker at windriver.com>
---
 arch/powerpc/kernel/irq.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 290559df1e8b..5c777e3a4c04 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -497,10 +497,12 @@ void __do_irq(struct pt_regs *regs)
 	may_hard_irq_enable();
 
 	/* And finally process it */
-	if (unlikely(irq == NO_IRQ))
+	if (unlikely(irq == NO_IRQ)) {
+		printk_ratelimited(KERN_WARNING "spurious irq on %d\n", irq);
 		__this_cpu_inc(irq_stat.spurious_irqs);
-	else
+	} else {
 		generic_handle_irq(irq);
+	}
 
 	trace_irq_exit(regs);
 
-- 
2.6.1