[PATCH] powerpc: Print information about mapping hw irqs to virtual irqs

Michael Ellerman michael at ellerman.id.au
Mon Apr 6 12:05:02 EST 2009

The irq remapping layer seems to cause some confusion when people
see a different irq number in /proc/interrupts vs the one they
request in their driver or DTS.

So have the irq remapping layer print out a message when we map an
irq. The message is only printed the first time the irq is mapped,
and it's KERN_DEBUG so most people won't see it.

Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
 arch/powerpc/kernel/irq.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 5576147..8c1a496 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -672,11 +672,13 @@ unsigned int irq_create_mapping(struct irq_host *host,
 			return NO_IRQ;
-	pr_debug("irq: -> obtained virq %d\n", virq);
 	if (irq_setup_virq(host, virq, hwirq))
 		return NO_IRQ;
+	printk(KERN_DEBUG "irq: irq %lu on host %s mapped to virtual irq %u\n",
+		hwirq, host->of_node ? host->of_node->full_name : "null", virq);
 	return virq;

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