genirq: Fix irqfixup, irqpoll regression

BugLink: http://bugs.launchpad.net/bugs/855199

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@numble.net>
Cc: maciej.rutecki@gmail.com
Link: http://lkml.kernel.org/r/1320175784-6745-1-git-send-email-edward.donovan@numble.net
Cc: stable@vger.kernel.org # >= 2.6.39
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
(cherry picked from commit c75d720fca8a91ce99196d33adea383621027bf2)

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Herton Krzesinski <herton.krzesinski@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index aa57d5da18c..b5f4742693c 100644
--- 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();