From: Frederic Weisbecker Date: Thu, 29 Dec 2016 16:45:49 +0000 (+0100) Subject: x86/apic: Implement set_state_oneshot_stopped() callback X-Git-Tag: v4.11-rc1~168^2~2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=914122c389d091a02f7b5476209af715e77ccb73;p=linux.git x86/apic: Implement set_state_oneshot_stopped() callback When clock_event_device::set_state_oneshot_stopped() is not implemented, hrtimer_cancel() can't stop the clock when there is no more timer in the queue. So the ghost of the freshly cancelled hrtimer haunts us back later with an extra interrupt: -0 [002] d..2 2248.557659: hrtimer_cancel: hrtimer=ffff88021fa92d80 -0 [002] d.h1 2249.303659: local_timer_entry: vector=239 So let's implement this missing callback for the lapic clock. This consist in calling its set_state_shutdown() callback. There don't seem to be a lighter way to stop the clock. Simply writing 0 to APIC_TMICT won't be enough to stop the clock and avoid the extra interrupt, as opposed to what is specified in the specs. We must also mask the timer interrupt in the device. Signed-off-by: Frederic Weisbecker Cc: Borislav Petkov Reviewed-by: Wanpeng Li Reviewed-by: Viresh Kumar Link: http://lkml.kernel.org/r/1483029949-6925-1-git-send-email-fweisbec@gmail.com Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 5c4fdcfda109..fdb9c46227cc 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -529,18 +529,19 @@ static void lapic_timer_broadcast(const struct cpumask *mask) * The local apic timer can be used for any function which is CPU local. */ static struct clock_event_device lapic_clockevent = { - .name = "lapic", - .features = CLOCK_EVT_FEAT_PERIODIC | - CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP - | CLOCK_EVT_FEAT_DUMMY, - .shift = 32, - .set_state_shutdown = lapic_timer_shutdown, - .set_state_periodic = lapic_timer_set_periodic, - .set_state_oneshot = lapic_timer_set_oneshot, - .set_next_event = lapic_next_event, - .broadcast = lapic_timer_broadcast, - .rating = 100, - .irq = -1, + .name = "lapic", + .features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP + | CLOCK_EVT_FEAT_DUMMY, + .shift = 32, + .set_state_shutdown = lapic_timer_shutdown, + .set_state_periodic = lapic_timer_set_periodic, + .set_state_oneshot = lapic_timer_set_oneshot, + .set_state_oneshot_stopped = lapic_timer_shutdown, + .set_next_event = lapic_next_event, + .broadcast = lapic_timer_broadcast, + .rating = 100, + .irq = -1, }; static DEFINE_PER_CPU(struct clock_event_device, lapic_events);