[PATCH] genirq: do not disable IRQ_WAKEUP marked irqs on suspend

[Thomas Gleixner <tglx@linutronix.de>]

commit 0a0c5168df (PM: Introduce functions for suspending and resuming
device interrupts) iterates through all interrupts and disables them
on the hardware level. Some architectures have functionality
implemented to mark an interrupt source as wakeup source for suspend,
but the new power management code disables them unconditionally which
breaks the resume on interrupt functionality.

The wakeup interrupts are marked in the status with the IRQ_WAKEUP
bit. Skip the disablement for those interrupts which have the
IRQ_WAKEUP bit set.
    
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org

diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index 638d8be..bce6afd 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -29,7 +29,8 @@ void suspend_device_irqs(void)
 		unsigned long flags;
 
 		spin_lock_irqsave(&desc->lock, flags);
-		__disable_irq(desc, irq, true);
+		if (!(desc->status & IRQ_WAKEUP))
+			__disable_irq(desc, irq, true);
 		spin_unlock_irqrestore(&desc->lock, flags);
 	}