[01/53] genirq: Fix irqfixup, irqpoll regression

[Greg KH]

3.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Edward Donovan <edward.donovan@xxxxxxxxxx>

commit c75d720fca8a91ce99196d33adea383621027bf2 upstream.

commit d05c65fff0 ("genirq: spurious: Run only one poller at a time")
introduced a regression, leaving the boot options 'irqfixup' and
'irqpoll' non-functional. The patch placed tests in each function, to
exit if the function is already running. The test in 'misrouted_irq'
exited when it should have proceeded, effectively disabling
'misrouted_irq' and 'poll_spurious_irqs'.

The check for an already running poller needs to be "!= 1" not "== 1"
as "1" is the value when the first poller starts running.

Signed-off-by: Edward Donovan <edward.donovan@xxxxxxxxxx>
Cc: maciej.rutecki@xxxxxxxxx
Link: http://lkml.kernel.org/r/1320175784-6745-1-git-send-email-edward.donovan@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 kernel/irq/spurious.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -115,7 +115,7 @@ static int misrouted_irq(int irq)
 	struct irq_desc *desc;
 	int i, ok = 0;
 
-	if (atomic_inc_return(&irq_poll_active) == 1)
+	if (atomic_inc_return(&irq_poll_active) != 1)
 		goto out;
 
 	irq_poll_cpu = smp_processor_id();


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