x86 hpet: Do nothing in hpet_broadcast_exit() if no timer deadline.

From: "Jiang, Yunhong" <yunhong.jiang@intel.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/xen/arch/x86/hpet.c b/xen/arch/x86/hpet.c
index c775aaa4869aebdfb8d517a3a89f21e901cec418..ec2a2b6afdb76c9c215f6a979f3b6ee3321a228f 100644 (file)
--- a/xen/arch/x86/hpet.c
+++ b/xen/arch/x86/hpet.c
@@ -660,6 +660,9 @@ void hpet_broadcast_exit(void)
     int cpu = smp_processor_id();
     struct hpet_event_channel *ch = per_cpu(cpu_bc_channel, cpu);
 
+    if ( this_cpu(timer_deadline) == 0 )
+        return;
+
     BUG_ON( !ch );
 
     spin_lock_irq(&ch->lock);