clockevents: Do not suspend/resume if unused

There is no point in calling suspend/resume for unused clockevents as
they are already stopped and disabled.

This is really important for AT91 as the hardware is a trainwreck and
takes ages to synchronize.

Reported-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1421399151-26800-1-git-send-email-alexandre.belloni@free-electrons.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 4922f1b805ea..2a5c369e50ab 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -638,7 +638,7 @@ void clockevents_suspend(void)
         struct clock_event_device *dev;
 
         list_for_each_entry_reverse(dev, &clockevent_devices, list)
-                if (dev->suspend)
+                if (dev->suspend && dev->mode != CLOCK_EVT_MODE_UNUSED)
                         dev->suspend(dev);
 }
 
@@ -650,7 +650,7 @@ void clockevents_resume(void)
         struct clock_event_device *dev;
 
         list_for_each_entry(dev, &clockevent_devices, list)
-                if (dev->resume)
+                if (dev->resume && dev->mode != CLOCK_EVT_MODE_UNUSED)
                         dev->resume(dev);
 }