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-rw-r--r--kernel/sched/idle.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index aaf1c1d5cf5d..94b2d7b88a27 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -7,6 +7,7 @@
#include <linux/tick.h>
#include <linux/mm.h>
#include <linux/stackprotector.h>
+#include <linux/suspend.h>
#include <asm/tlb.h>
@@ -105,6 +106,21 @@ static void cpuidle_idle_call(void)
rcu_idle_enter();
/*
+ * Suspend-to-idle ("freeze") is a system state in which all user space
+ * has been frozen, all I/O devices have been suspended and the only
+ * activity happens here and in iterrupts (if any). In that case bypass
+ * the cpuidle governor and go stratight for the deepest idle state
+ * available. Possibly also suspend the local tick and the entire
+ * timekeeping to prevent timer interrupts from kicking us out of idle
+ * until a proper wakeup interrupt happens.
+ */
+ if (idle_should_freeze()) {
+ cpuidle_enter_freeze();
+ local_irq_enable();
+ goto exit_idle;
+ }
+
+ /*
* Ask the cpuidle framework to choose a convenient idle state.
* Fall back to the default arch idle method on errors.
*/