clock events: allow replacement of broadcast timer

Change the broadcast timer, if a timer with higher rating becomes available.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 8 insertions, 9 deletions

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index acf15b49e55..298bc7c6f09 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -64,8 +64,9 @@ static void tick_broadcast_start_periodic(struct clock_event_device *bc)
  */
 int tick_check_broadcast_device(struct clock_event_device *dev)
 {
-        if (tick_broadcast_device.evtdev ||
-            (dev->features & CLOCK_EVT_FEAT_C3STOP))
+        if ((tick_broadcast_device.evtdev &&
+             tick_broadcast_device.evtdev->rating >= dev->rating) ||
+             (dev->features & CLOCK_EVT_FEAT_C3STOP))
                 return 0;
 
         clockevents_exchange_device(NULL, dev);
@@ -513,11 +514,9 @@ static void tick_broadcast_clear_oneshot(int cpu)
  */
 void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
 {
-        if (bc->mode != CLOCK_EVT_MODE_ONESHOT) {
-                bc->event_handler = tick_handle_oneshot_broadcast;
-                clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
-                bc->next_event.tv64 = KTIME_MAX;
-        }
+        bc->event_handler = tick_handle_oneshot_broadcast;
+        clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
+        bc->next_event.tv64 = KTIME_MAX;
 }
 
 /*
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 77a21abc871..3f3ae390783 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -200,7 +200,7 @@ static int tick_check_new_device(struct clock_event_device *newdev)
 
         cpu = smp_processor_id();
         if (!cpu_isset(cpu, newdev->cpumask))
-                goto out;
+                goto out_bc;
 
         td = &per_cpu(tick_cpu_device, cpu);
         curdev = td->evtdev;
@@ -265,7 +265,7 @@ out_bc:
          */
         if (tick_check_broadcast_device(newdev))
                 ret = NOTIFY_STOP;
-out:
+
         spin_unlock_irqrestore(&tick_device_lock, flags);
 
         return ret;