1 files changed, 33 insertions, 17 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 438a01464287..46d6611a33bb 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/random.h>
 #include <linux/interrupt.h>
+#include <linux/slab.h>
 
 #include "internals.h"
 
@@ -149,6 +150,26 @@ void disable_irq(unsigned int irq)
 }
 EXPORT_SYMBOL(disable_irq);
 
+static void __enable_irq(struct irq_desc *desc, unsigned int irq)
+{
+	switch (desc->depth) {
+	case 0:
+		printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
+		WARN_ON(1);
+		break;
+	case 1: {
+		unsigned int status = desc->status & ~IRQ_DISABLED;
+
+		/* Prevent probing on this irq: */
+		desc->status = status | IRQ_NOPROBE;
+		check_irq_resend(desc, irq);
+		/* fall-through */
+	}
+	default:
+		desc->depth--;
+	}
+}
+
 /**
  *	enable_irq - enable handling of an irq
  *	@irq: Interrupt to enable
@@ -168,22 +189,7 @@ void enable_irq(unsigned int irq)
 		return;
 
 	spin_lock_irqsave(&desc->lock, flags);
-	switch (desc->depth) {
-	case 0:
-		printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
-		WARN_ON(1);
-		break;
-	case 1: {
-		unsigned int status = desc->status & ~IRQ_DISABLED;
-
-		/* Prevent probing on this irq: */
-		desc->status = status | IRQ_NOPROBE;
-		check_irq_resend(desc, irq);
-		/* fall-through */
-	}
-	default:
-		desc->depth--;
-	}
+	__enable_irq(desc, irq);
 	spin_unlock_irqrestore(&desc->lock, flags);
 }
 EXPORT_SYMBOL(enable_irq);
@@ -364,7 +370,7 @@ int setup_irq(unsigned int irq, struct irqaction *new)
 			compat_irq_chip_set_default_handler(desc);
 
 		desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
-				  IRQ_INPROGRESS);
+				  IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
 
 		if (!(desc->status & IRQ_NOAUTOEN)) {
 			desc->depth = 0;
@@ -380,6 +386,16 @@ int setup_irq(unsigned int irq, struct irqaction *new)
 	/* Reset broken irq detection when installing new handler */
 	desc->irq_count = 0;
 	desc->irqs_unhandled = 0;
+
+	/*
+	 * Check whether we disabled the irq via the spurious handler
+	 * before. Reenable it and give it another chance.
+	 */
+	if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
+		desc->status &= ~IRQ_SPURIOUS_DISABLED;
+		__enable_irq(desc, irq);
+	}
+
 	spin_unlock_irqrestore(&desc->lock, flags);
 
 	new->irq = irq;