rangetimer: fix BUG_ON reported by Ingo

There's a small race/chance that, while hrtimers are enabled globally,
they're later not enabled when we're calling the hrtimer_interrupt() function,
which then BUG_ON()'s for that. This patch closes that race/gap.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index eb2cf984959..b17657d8d81 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1395,11 +1395,15 @@ void hrtimer_peek_ahead_timers(void)
         unsigned long flags;
         struct tick_device *td;
         struct clock_event_device *dev;
-
+        struct hrtimer_cpu_base *cpu_base;
         if (hrtimer_hres_active())
                 return;
 
         local_irq_save(flags);
+        cpu_base = &__get_cpu_var(hrtimer_bases);
+        if (!cpu_base->hres_active)
+                goto out;
+
         td = &__get_cpu_var(tick_cpu_device);
         if (!td)
                 goto out;