1 files changed, 26 insertions, 2 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 4e461438e48b..92be519eff26 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -137,16 +137,40 @@ EXPORT_SYMBOL(enable_irq);
  *      @irq:   interrupt to control
  *      @on:    enable/disable power management wakeup
  *
- *      Enable/disable power management wakeup mode
+ *      Enable/disable power management wakeup mode, which is
+ *      disabled by default.  Enables and disables must match,
+ *      just as they match for non-wakeup mode support.
+ *
+ *      Wakeup mode lets this IRQ wake the system from sleep
+ *      states like "suspend to RAM".
  */
 int set_irq_wake(unsigned int irq, unsigned int on)
 {
         struct irq_desc *desc = irq_desc + irq;
         unsigned long flags;
         int ret = -ENXIO;
+        int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake;
 
+        /* wakeup-capable irqs can be shared between drivers that
+         * don't need to have the same sleep mode behaviors.
+         */
         spin_lock_irqsave(&desc->lock, flags);
-        if (desc->chip->set_wake)
+        if (on) {
+                if (desc->wake_depth++ == 0)
+                        desc->status |= IRQ_WAKEUP;
+                else
+                        set_wake = NULL;
+        } else {
+                if (desc->wake_depth == 0) {
+                        printk(KERN_WARNING "Unbalanced IRQ %d "
+                                        "wake disable\n", irq);
+                        WARN_ON(1);
+                } else if (--desc->wake_depth == 0)
+                        desc->status &= ~IRQ_WAKEUP;
+                else
+                        set_wake = NULL;
+        }
+        if (set_wake)
                 ret = desc->chip->set_wake(irq, on);
         spin_unlock_irqrestore(&desc->lock, flags);
         return ret;