idle / sleep: Avoid excessive disabling and enabling interrupts

Disabling interrupts at the end of cpuidle_enter_freeze() is not
useful, because its caller, cpuidle_idle_call(), re-enables them
right away after invoking it.

To avoid that unnecessary back and forth dance with interrupts,
make cpuidle_enter_freeze() enable interrupts after calling
enter_freeze_proper() and drop the local_irq_disable() at its
end, so that all of the code paths in it end up with interrupts
enabled.  Then, cpuidle_idle_call() will not need to re-enable
interrupts after calling cpuidle_enter_freeze() any more, because
the latter will return with interrupts enabled, in analogy with
cpuidle_enter().

Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 94b2d7b88a27..f59198bda1bf 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -116,7 +116,6 @@ static void cpuidle_idle_call(void)
          */
         if (idle_should_freeze()) {
                 cpuidle_enter_freeze();
-                local_irq_enable();
                 goto exit_idle;
         }