[PATCH] uml: make hw_controller_type->release exist only for archs needing it

With Chris Wedgwood <cw@f00f.org>

As suggested by Chris, we can make the "just added" method ->release
conditional to UML only (better: to archs requesting it, i.e.  only UML
currently), so that other archs don't get this unneeded crud, and if UML
won't need it any more we can kill this.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 12 insertions, 0 deletions

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index c5292181a664..b8e952c88fd1 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -35,6 +35,11 @@ config GENERIC_CALIBRATE_DELAY
         bool
         default y
 
+# Used in kernel/irq/manage.c and include/linux/irq.h
+config IRQ_RELEASE_METHOD
+        bool
+        default y
+
 menu "UML-specific options"
 
 config MODE_TT
diff --git a/include/linux/irq.h b/include/linux/irq.h
index b68ad80e2464..7fc1022be9ee 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -47,7 +47,10 @@ struct hw_interrupt_type {
         void (*ack)(unsigned int irq);
         void (*end)(unsigned int irq);
         void (*set_affinity)(unsigned int irq, cpumask_t dest);
+        /* Currently used only by UML, might disappear one day.*/
+#ifdef CONFIG_IRQ_RELEASE_METHOD
         void (*release)(unsigned int irq, void *dev_id);
+#endif
 };
 
 typedef struct hw_interrupt_type  hw_irq_controller;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 5fde8177eedf..ac6700985705 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -6,6 +6,7 @@
  * This file contains driver APIs to the irq subsystem.
  */
 
+#include <linux/config.h>
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/random.h>
@@ -256,8 +257,11 @@ void free_irq(unsigned int irq, void *dev_id)
                         /* Found it - now remove it from the list of entries */
                         *pp = action->next;
 
+                        /* Currently used only by UML, might disappear one day.*/
+#ifdef CONFIG_IRQ_RELEASE_METHOD
                         if (desc->handler->release)
                                 desc->handler->release(irq, dev_id);
+#endif
 
                         if (!desc->action) {
                                 desc->status |= IRQ_DISABLED;