1 files changed, 55 insertions, 11 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index cbd97ce0b00..a2b28a2fd7b 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -40,10 +40,9 @@ int irq_set_chip(unsigned int irq, struct irq_chip *chip)
 	irq_put_desc_unlock(desc, flags);
 	/*
 	 * For !CONFIG_SPARSE_IRQ make the irq show up in
-	 * allocated_irqs. For the CONFIG_SPARSE_IRQ case, it is
-	 * already marked, and this call is harmless.
+	 * allocated_irqs.
 	 */
-	irq_reserve_irq(irq);
+	irq_mark_irq(irq);
 	return 0;
 }
 EXPORT_SYMBOL(irq_set_chip);
@@ -213,6 +212,19 @@ void irq_enable(struct irq_desc *desc)
 	irq_state_clr_masked(desc);
 }
 
+/**
+ * irq_disable - Mark interrupt disabled
+ * @desc:	irq descriptor which should be disabled
+ *
+ * If the chip does not implement the irq_disable callback, we
+ * use a lazy disable approach. That means we mark the interrupt
+ * disabled, but leave the hardware unmasked. That's an
+ * optimization because we avoid the hardware access for the
+ * common case where no interrupt happens after we marked it
+ * disabled. If an interrupt happens, then the interrupt flow
+ * handler masks the line at the hardware level and marks it
+ * pending.
+ */
 void irq_disable(struct irq_desc *desc)
 {
 	irq_state_set_disabled(desc);
@@ -268,6 +280,19 @@ void unmask_irq(struct irq_desc *desc)
 	}
 }
 
+void unmask_threaded_irq(struct irq_desc *desc)
+{
+	struct irq_chip *chip = desc->irq_data.chip;
+
+	if (chip->flags & IRQCHIP_EOI_THREADED)
+		chip->irq_eoi(&desc->irq_data);
+
+	if (chip->irq_unmask) {
+		chip->irq_unmask(&desc->irq_data);
+		irq_state_clr_masked(desc);
+	}
+}
+
 /*
  *	handle_nested_irq - Handle a nested irq from a irq thread
  *	@irq:	the interrupt number
@@ -422,6 +447,27 @@ static inline void preflow_handler(struct irq_desc *desc)
 static inline void preflow_handler(struct irq_desc *desc) { }
 #endif
 
+static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
+{
+	if (!(desc->istate & IRQS_ONESHOT)) {
+		chip->irq_eoi(&desc->irq_data);
+		return;
+	}
+	/*
+	 * We need to unmask in the following cases:
+	 * - Oneshot irq which did not wake the thread (caused by a
+	 *   spurious interrupt or a primary handler handling it
+	 *   completely).
+	 */
+	if (!irqd_irq_disabled(&desc->irq_data) &&
+	    irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {
+		chip->irq_eoi(&desc->irq_data);
+		unmask_irq(desc);
+	} else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {
+		chip->irq_eoi(&desc->irq_data);
+	}
+}
+
 /**
  *	handle_fasteoi_irq - irq handler for transparent controllers
  *	@irq:	the interrupt number
@@ -435,6 +481,8 @@ static inline void preflow_handler(struct irq_desc *desc) { }
 void
 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 {
+	struct irq_chip *chip = desc->irq_data.chip;
+
 	raw_spin_lock(&desc->lock);
 
 	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
@@ -460,18 +508,14 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 	preflow_handler(desc);
 	handle_irq_event(desc);
 
-	if (desc->istate & IRQS_ONESHOT)
-		cond_unmask_irq(desc);
+	cond_unmask_eoi_irq(desc, chip);
 
-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;
+	if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
+		chip->irq_eoi(&desc->irq_data);
+	raw_spin_unlock(&desc->lock);
 }
 
 /**