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-rw-r--r--kernel/irq/manage.c28
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;