path: root/drivers/cpuidle/cpuidle.c
diff options
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-04-29 15:19:21 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-04-29 15:19:21 +0200
commitdf8d9eeadd0f7a216f2476351d5aee43c6550bf0 (patch)
tree5290522027dd4acd6912c69446ad181c2aff4324 /drivers/cpuidle/cpuidle.c
parentb787f68c36d49bb1d9236f403813641efa74a031 (diff)
cpuidle: Run tick_broadcast_exit() with disabled interrupts
Commit 335f49196fd6 (sched/idle: Use explicit broadcast oneshot control function) replaced clockevents_notify() invocations in cpuidle_idle_call() with direct calls to tick_broadcast_enter() and tick_broadcast_exit(), but it overlooked the fact that interrupts were already enabled before calling the latter which led to functional breakage on systems using idle states with the CPUIDLE_FLAG_TIMER_STOP flag set. Fix that by moving the invocations of tick_broadcast_enter() and tick_broadcast_exit() down into cpuidle_enter_state() where interrupts are still disabled when tick_broadcast_exit() is called. Also ensure that interrupts will be disabled before running tick_broadcast_exit() even if they have been enabled by the idle state's ->enter callback. Trigger a WARN_ON_ONCE() in that case, as we generally don't want that to happen for states with CPUIDLE_FLAG_TIMER_STOP set. Fixes: 335f49196fd6 (sched/idle: Use explicit broadcast oneshot control function) Reported-and-tested-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle/cpuidle.c')
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 7a73a279e179..61c417b9e53f 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -158,9 +158,18 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
int entered_state;
struct cpuidle_state *target_state = &drv->states[index];
+ bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP);
ktime_t time_start, time_end;
s64 diff;
+ /*
+ * Tell the time framework to switch to a broadcast timer because our
+ * local timer will be shut down. If a local timer is used from another
+ * CPU as a broadcast timer, this call may fail if it is not available.
+ */
+ if (broadcast && tick_broadcast_enter())
+ return -EBUSY;
trace_cpu_idle_rcuidle(index, dev->cpu);
time_start = ktime_get();
@@ -169,6 +178,13 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
time_end = ktime_get();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
+ if (broadcast) {
+ if (WARN_ON_ONCE(!irqs_disabled()))
+ local_irq_disable();
+ tick_broadcast_exit();
+ }
if (!cpuidle_state_is_coupled(dev, drv, entered_state))