From 39c82caff8610d57ffe32157cb3130dfabe12fbe Mon Sep 17 00:00:00 2001 From: Prasad Sodagudi Date: Thu, 26 Oct 2017 11:37:22 -0700 Subject: [PATCH] clockevents: Update clockevents device next_event on stop clockevent_device::next_event holds the next timer event of a clock event device. The value is updated in clockevents_program_event(), i.e. when the hardware timer is armed for the next expiry. When there are no software timers armed on a CPU, the corresponding per CPU clockevent device is brought into ONESHOT_STOPPED state, but clockevent_device::next_event is not updated, because clockevents_program_event() is not called. So the content of clockevent_device::next_event is stale, which is not an issue when real hardware is used. But the hrtimer broadcast device relies on that information and the stale value causes spurious wakeups. Update clockevent_device::next_event to KTIME_MAX when it has been brought into ONESHOT_STOPPED state to avoid spurious wakeups. This reflects the proper expiry time of the stopped timer: infinity. [ tglx: Massaged changelog ] Signed-off-by: Prasad Sodagudi Signed-off-by: Thomas Gleixner Cc: viresh.kumar@linaro.org Link: https://lkml.kernel.org/r/1509043042-32486-1-git-send-email-psodagud@codeaurora.org --- kernel/time/tick-oneshot.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c index 6b009c207671..c1f518e7aa80 100644 --- a/kernel/time/tick-oneshot.c +++ b/kernel/time/tick-oneshot.c @@ -33,6 +33,7 @@ int tick_program_event(ktime_t expires, int force) * We don't need the clock event device any more, stop it. */ clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT_STOPPED); + dev->next_event = KTIME_MAX; return 0; }