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>

1 files changed, 27 insertions, 12 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 77a51be36010..3cfc0fefb5ee 100644
--- 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;
 }