genirq: Do not mask edge ONESHOT interrupts

Edge type oneshot interrupts should not be masked for forced
threading. We might lose interrupts.

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

1 files changed, 8 insertions, 9 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 027fd5b83f26..c6f2d0ad1756 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -536,7 +536,12 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 {
         atomic_spin_lock(&desc->lock);
 
-        desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+        /*
+         * Edge irqs can be requested with IRQF_ONESHOT set. RT
+         * (ab)uses this for enforced irq threading, but we do not
+         * want to mask edge type interrupts. Clear the oneshot flag.
+         */
+        desc->status &= ~(IRQ_REPLAY | IRQ_WAITING | IRQ_ONESHOT);
 
         /*
          * If we're currently running this IRQ, or its disabled,
@@ -551,14 +556,8 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
         }
         kstat_incr_irqs_this_cpu(irq, desc);
 
-        /* Start handling the irq */
-        if (unlikely(desc->status & IRQ_ONESHOT)) {
-                desc->status |= IRQ_MASKED;
-                mask_ack_irq(desc, irq);
-        } else {
-                if (desc->chip->ack)
-                        desc->chip->ack(irq);
-        }
+        if (desc->chip->ack)
+                desc->chip->ack(irq);
 
         /* Mark the IRQ currently in progress.*/
         desc->status |= IRQ_INPROGRESS;