[PATCH 2/2] tick: Fix the spurious broadcast timer ticks

[Suresh Siddha]

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@xxxxxxxxx>
---
 kernel/time/tick-broadcast.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 0e5597e..4c26100 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;
 		}
 	}
-- 
1.7.5.4


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