Fix CONFIG_DEBUG_SHIRQ trigger on free_irq()
David Woodhouse [Wed, 17 Oct 2007 06:26:29 +0000 (23:26 -0700)]
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>

kernel/irq/manage.c

index 7230d91..80eab7a 100644 (file)
@@ -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);