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-rw-r--r--include/linux/irq.h3
-rw-r--r--kernel/irq/manage.c28
2 files changed, 29 insertions, 2 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index b48eae3..6e59ac0 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -58,6 +58,7 @@
#define IRQ_NOREQUEST 0x04000000 /* IRQ cannot be requested */
#define IRQ_NOAUTOEN 0x08000000 /* IRQ will not be enabled on request irq */
#define IRQ_DELAYED_DISABLE 0x10000000 /* IRQ disable (masking) happens delayed. */
+#define IRQ_WAKEUP 0x20000000 /* IRQ triggers system wakeup */
struct proc_dir_entry;
@@ -124,6 +125,7 @@ struct irq_chip {
* @action: the irq action chain
* @status: status information
* @depth: disable-depth, for nested irq_disable() calls
+ * @wake_depth: enable depth, for multiple set_irq_wake() callers
* @irq_count: stats field to detect stalled irqs
* @irqs_unhandled: stats field for spurious unhandled interrupts
* @lock: locking for SMP
@@ -147,6 +149,7 @@ struct irq_desc {
unsigned int status; /* IRQ status */
unsigned int depth; /* nested irq disables */
+ unsigned int wake_depth; /* nested wake enables */
unsigned int irq_count; /* For detecting broken IRQs */
unsigned int irqs_unhandled;
spinlock_t lock;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 4e46143..92be519 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;
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