genirq: Add IRQCHIP_SKIP_SET_WAKE flag

Some irq chips need the irq_set_wake() functionality, but do not
require a irq_set_wake() callback. Instead of forcing an empty
callback to be implemented add a flag which notes this fact. Check for
the flag in set_irq_wake_real() and return success when set.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 59517300a315..73e31abeba1c 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -336,12 +336,14 @@ struct irq_chip {
  * IRQCHIP_MASK_ON_SUSPEND:     Mask non wake irqs in the suspend path
  * IRQCHIP_ONOFFLINE_ENABLED:   Only call irq_on/off_line callbacks
  *                              when irq enabled
+ * IRQCHIP_SKIP_SET_WAKE:       Skip chip.irq_set_wake(), for this irq chip
  */
 enum {
         IRQCHIP_SET_TYPE_MASKED         = (1 <<  0),
         IRQCHIP_EOI_IF_HANDLED          = (1 <<  1),
         IRQCHIP_MASK_ON_SUSPEND         = (1 <<  2),
         IRQCHIP_ONOFFLINE_ENABLED       = (1 <<  3),
+        IRQCHIP_SKIP_SET_WAKE           = (1 <<  4),
 };
 
 /* This include will go away once we isolated irq_desc usage to core code */
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 9b956fa20308..7e1a3ed1e61a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -467,6 +467,9 @@ static int set_irq_wake_real(unsigned int irq, unsigned int on)
         struct irq_desc *desc = irq_to_desc(irq);
         int ret = -ENXIO;
 
+        if (irq_desc_get_chip(desc)->flags &  IRQCHIP_SKIP_SET_WAKE)
+                return 0;
+
         if (desc->irq_data.chip->irq_set_wake)
                 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);