Fix CONFIG_DEBUG_SHIRQ trigger on free_irq()

Andy Gospodarek pointed out that because we return in the middle of the
free_irq() function, we never actually do call the IRQ handler that just
got deregistered. This should fix it, although I expect Andrew will want
to convert those 'return's to 'break'. That's a separate change though.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Fernando Luis Vzquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 16 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 7230d914eaa2..80eab7a04205 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -405,7 +405,6 @@ void free_irq(unsigned int irq, void *dev_id)
         struct irq_desc *desc;
         struct irqaction **p;
         unsigned long flags;
-        irqreturn_t (*handler)(int, void *) = NULL;
 
         WARN_ON(in_interrupt());
         if (irq >= NR_IRQS)
@@ -445,8 +444,21 @@ void free_irq(unsigned int irq, void *dev_id)
 
                         /* Make sure it's not being used on another CPU */
                         synchronize_irq(irq);
-                        if (action->flags & IRQF_SHARED)
-                                handler = action->handler;
+#ifdef CONFIG_DEBUG_SHIRQ
+                        /*
+                         * It's a shared IRQ -- the driver ought to be
+                         * prepared for it to happen even now it's
+                         * being freed, so let's make sure....  We do
+                         * this after actually deregistering it, to
+                         * make sure that a 'real' IRQ doesn't run in
+                         * parallel with our fake
+                         */
+                        if (action->flags & IRQF_SHARED) {
+                                local_irq_save(flags);
+                                action->handler(irq, dev_id);
+                                local_irq_restore(flags);
+                        }
+#endif
                         kfree(action);
                         return;
                 }
@@ -454,19 +466,6 @@ void free_irq(unsigned int irq, void *dev_id)
                 spin_unlock_irqrestore(&desc->lock, flags);
                 return;
         }
-#ifdef CONFIG_DEBUG_SHIRQ
-        if (handler) {
-                /*
-                 * It's a shared IRQ -- the driver ought to be prepared for it
-                 * to happen even now it's being freed, so let's make sure....
-                 * We do this after actually deregistering it, to make sure that
-                 * a 'real' IRQ doesn't run in parallel with our fake
-                 */
-                local_irq_save(flags);
-                handler(irq, dev_id);
-                local_irq_restore(flags);
-        }
-#endif
 }
 EXPORT_SYMBOL(free_irq);