genirq; Add fasteoi irq_chip quirk

Some chips want irq_eoi() only called when an interrupt is actually
handled. So they have checks for INPROGRESS and DISABLED in their
irq_eoi callbacks. Add a chip flag, which allows to handle that in the
generic code. No impact on the fastpath.

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

2 files changed, 11 insertions, 2 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 36390970693c..ea2970c294aa 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -328,10 +328,12 @@ struct irq_chip {
 /*
  * irq_chip specific flags
  *
- * IRQCHIP_SET_TYPE_MASKED:             Mask before calling chip.irq_set_type()
+ * IRQCHIP_SET_TYPE_MASKED:     Mask before calling chip.irq_set_type()
+ * IRQCHIP_EOI_IF_HANDLED:      Only issue irq_eoi() when irq was handled
  */
 enum {
         IRQCHIP_SET_TYPE_MASKED         = (1 <<  0),
+        IRQCHIP_EOI_IF_HANDLED          = (1 <<  1),
 };
 
 /* This include will go away once we isolated irq_desc usage to core code */
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 08be5d182be3..1d3e25e68b0c 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -515,9 +515,16 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
         }
         preflow_handler(desc);
         handle_irq_event(desc);
-out:
+
+out_eoi:
         desc->irq_data.chip->irq_eoi(&desc->irq_data);
+out_unlock:
         raw_spin_unlock(&desc->lock);
+        return;
+out:
+        if (!(desc->irq_data.chip->flags & IRQCHIP_EOI_IF_HANDLED))
+                goto out_eoi;
+        goto out_unlock;
 }
 
 /**