rtc: remove and clarify unneeded externs

When CONFIG_HPET_EMULATE_RTC is defined the external declaration of
hpet_rtc_interrupt is redundant due to the inclusion of hpet.h.

When !CONFIG_HPET_EMULATE_RTC we make it clear that hpet_rtc_interrupt is
not used by defining it to return zero.

Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 4 insertions, 3 deletions

diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c
index d1569a0d0506..dbefbb30ed44 100644
--- a/drivers/char/rtc.c
+++ b/drivers/char/rtc.c
@@ -121,8 +121,6 @@ static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
         return 0;
 }
 #endif
-#else
-extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
 #endif
 
 /*
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index d7bb9bac71df..94b89a2d9c2e 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -52,7 +52,10 @@
 #define hpet_rtc_timer_init()                   do { } while (0)
 #define hpet_register_irq_handler(h)            0
 #define hpet_unregister_irq_handler(h)          do { } while (0)
-extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
+static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
+{
+        return 0;
+}
 #endif
 
 struct cmos_rtc {