tick: Fix the spurious broadcast timer ticks after resume

During resume, tick_resume_broadcast() programs the broadcast timer in
oneshot mode unconditionally. On the platforms where broadcast timer
is not really required, this will generate spurious broadcast timer
ticks upon resume. For example, on the always running apic timer
platforms with HPET, I see spurious hpet tick once every ~5minutes
(which is the 32-bit hpet counter wraparound time).

Similar to boot time, during resume make the oneshot mode setting of
the broadcast clock event device conditional on the state of active
broadcast users.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: svenjoac@gmx.de
Cc: torvalds@linux-foundation.org
Cc: rjw@sisk.pl
Link: http://lkml.kernel.org/r/1334802459.28674.209.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 029531f3818c..f113755695e2 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -346,7 +346,8 @@ int tick_resume_broadcast(void)
                                                      tick_get_broadcast_mask());
                         break;
                 case TICKDEV_MODE_ONESHOT:
-                        broadcast = tick_resume_broadcast_oneshot(bc);
+                        if (!cpumask_empty(tick_get_broadcast_mask()))
+                                broadcast = tick_resume_broadcast_oneshot(bc);
                         break;
                 }
         }