[patch 2/3] genirq: suppress resend of level interrupts

[Thomas Gleixner <tglx@linutronix.de>]

[-- Attachment #1: genirq-do-suppress-resend-of-level-type-interrupts.patch --]
[-- Type: text/plain, Size: 1041 bytes --]

Level type interrupts are resent by the interrupt hardware when
they are still active at irq_enable().

Suppress the resend mechanism for interrupts marked as level.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 kernel/irq/resend.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Index: linux-2.6/kernel/irq/resend.c
===================================================================
--- linux-2.6.orig/kernel/irq/resend.c	2007-08-12 17:18:04.000000000 +0200
+++ linux-2.6/kernel/irq/resend.c	2007-08-12 17:18:04.000000000 +0200
@@ -62,7 +62,12 @@ void check_irq_resend(struct irq_desc *d
 	 */
 	desc->chip->enable(irq);
 
-	if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
+	/*
+	 * We do not resend level type interrupts. Level type
+	 * interrupts are resent by hardware when they are still
+	 * active.
+	 */
+	if ((status & (IRQ_LEVEL | IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
 		desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;
 
 		if (!desc->chip || !desc->chip->retrigger ||

--