ns9xxx: fix handle_prio_irq to unmask irqs with lower priority

When an irq is reported all lower prio irqs are masked until the current
irq is acked.  So never leave handle_prio_irq without acking.

desc->status & IRQ_INPROGRESS should never become true because the current
irq is masked until it is acked, too.

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>

1 files changed, 9 insertions, 6 deletions

diff --git a/arch/arm/mach-ns9xxx/irq.c b/arch/arm/mach-ns9xxx/irq.c
index 7ddc8fde7748..ba7a9e4888f0 100644
--- a/arch/arm/mach-ns9xxx/irq.c
+++ b/arch/arm/mach-ns9xxx/irq.c
@@ -64,15 +64,14 @@ void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
 
         spin_lock(&desc->lock);
 
-        if (unlikely(desc->status & IRQ_INPROGRESS))
-                goto out_unlock;
+        BUG_ON(desc->status & IRQ_INPROGRESS);
 
         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
         kstat_cpu(cpu).irqs[irq]++;
 
         action = desc->action;
         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
-                goto out_unlock;
+                goto out_mask;
 
         desc->status |= IRQ_INPROGRESS;
         spin_unlock(&desc->lock);
@@ -81,10 +80,14 @@ void handle_prio_irq(unsigned int irq, struct irq_desc *desc)
 
         spin_lock(&desc->lock);
         desc->status &= ~IRQ_INPROGRESS;
-        if (!(desc->status & IRQ_DISABLED) && desc->chip->ack)
-                desc->chip->ack(irq);
 
-out_unlock:
+        if (desc->status & IRQ_DISABLED)
+out_mask:
+                desc->chip->mask(irq);
+
+        /* ack unconditionally to unmask lower prio irqs */
+        desc->chip->ack(irq);
+
         spin_unlock(&desc->lock);
 }
 #define handle_irq handle_prio_irq