genirq: spurious: Run only one poller at a time

No point in running concurrent pollers which confuse each other by
setting PENDING.

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

1 files changed, 15 insertions, 1 deletions

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index bd0e42d3e0ba..56ff8fffb8b0 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -21,6 +21,8 @@ static int irqfixup __read_mostly;
 #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10)
 static void poll_spurious_irqs(unsigned long dummy);
 static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0);
+static int irq_poll_cpu;
+static atomic_t irq_poll_active;
 
 /*
  * Recovery handler for misrouted interrupts.
@@ -92,6 +94,11 @@ static int misrouted_irq(int irq)
         struct irq_desc *desc;
         int i, ok = 0;
 
+        if (atomic_inc_return(&irq_poll_active) == 1)
+                goto out;
+
+        irq_poll_cpu = smp_processor_id();
+
         for_each_irq_desc(i, desc) {
                 if (!i)
                          continue;
@@ -102,6 +109,8 @@ static int misrouted_irq(int irq)
                 if (try_one_irq(i, desc, false))
                         ok = 1;
         }
+out:
+        atomic_dec(&irq_poll_active);
         /* So the caller can adjust the irq error counts */
         return ok;
 }
@@ -111,6 +120,10 @@ static void poll_spurious_irqs(unsigned long dummy)
         struct irq_desc *desc;
         int i;
 
+        if (atomic_inc_return(&irq_poll_active) != 1)
+                goto out;
+        irq_poll_cpu = smp_processor_id();
+
         for_each_irq_desc(i, desc) {
                 unsigned int status;
 
@@ -127,7 +140,8 @@ static void poll_spurious_irqs(unsigned long dummy)
                 try_one_irq(i, desc, true);
                 local_irq_enable();
         }
-
+out:
+        atomic_dec(&irq_poll_active);
         mod_timer(&poll_spurious_irq_timer,
                   jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
 }