set_irq_wake: fix return code and wake status tracking

Since 15a647eba94c3da27ccc666bea72e7cca06b2d19 set_irq_wake returned -ENXIO
if another device had it already enabled.  Zero is the right value to
return in this case.  Moreover the change to desc->status was not reverted
if desc->chip->set_wake returned an error.

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 77a51be360103c98c8ce3a165668ea423f69d119..3cfc0fefb5ee671e1565862f1b54ee431af4eb8a 100644 (file)
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -217,6 +217,17 @@ void enable_irq(unsigned int irq)
 }
 EXPORT_SYMBOL(enable_irq);
 
+int set_irq_wake_real(unsigned int irq, unsigned int on)
+{
+       struct irq_desc *desc = irq_desc + irq;
+       int ret = -ENXIO;
+
+       if (desc->chip->set_wake)
+               ret = desc->chip->set_wake(irq, on);
+
+       return ret;
+}
+
 /**
  *     set_irq_wake - control irq power management wakeup
  *     @irq:   interrupt to control
@@ -233,30 +244,34 @@ 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;
+       int ret = 0;
 
        /* 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 (on) {
-               if (desc->wake_depth++ == 0)
-                       desc->status |= IRQ_WAKEUP;
-               else
-                       set_wake = NULL;
+               if (desc->wake_depth++ == 0) {
+                       ret = set_irq_wake_real(irq, on);
+                       if (ret)
+                               desc->wake_depth = 0;
+                       else
+                               desc->status |= IRQ_WAKEUP;
+               }
        } 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;
+               } else if (--desc->wake_depth == 0) {
+                       ret = set_irq_wake_real(irq, on);
+                       if (ret)
+                               desc->wake_depth = 1;
+                       else
+                               desc->status &= ~IRQ_WAKEUP;
+               }
        }
-       if (set_wake)
-               ret = desc->chip->set_wake(irq, on);
+
        spin_unlock_irqrestore(&desc->lock, flags);
        return ret;
 }