cpuidle / ACPI: remove unused CPUIDLE_FLAG_TIME_INVALID

CPUIDLE_FLAG_TIME_INVALID is no longer checked
by menu or ladder cpuidle governors, so don't
bother setting or defining it.

It was originally invented to account for the fact that
acpi_safe_halt() enables interrupts to invoke HLT.
That would allow interrupt service routines to be included
in the last_idle duration measurements made in cpuidle_enter_state(),
potentially returning a duration much larger than reality.

But menu and ladder can gracefully handle erroneously large duration
intervals without checking for CPUIDLE_FLAG_TIME_INVALID.
Further, if they don't check CPUIDLE_FLAG_TIME_INVALID, they
can also benefit from the instances when the duration interval
is not erroneously large.

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

2 files changed, 0 insertions, 5 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 380b4b43f361..7afba40e350e 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -985,8 +985,6 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
                 state->flags = 0;
                 switch (cx->type) {
                         case ACPI_STATE_C1:
-                        if (cx->entry_method != ACPI_CSTATE_FFH)
-                                state->flags |= CPUIDLE_FLAG_TIME_INVALID;
 
                         state->enter = acpi_idle_enter_c1;
                         state->enter_dead = acpi_idle_play_dead;
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index a07e087f54b2..ab70f3bc44ad 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -53,7 +53,6 @@ struct cpuidle_state {
 };
 
 /* Idle State Flags */
-#define CPUIDLE_FLAG_TIME_INVALID       (0x01) /* is residency time measurable? */
 #define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
 
@@ -89,8 +88,6 @@ DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
 /**
  * cpuidle_get_last_residency - retrieves the last state's residency time
  * @dev: the target CPU
- *
- * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_INVALID is set
  */
 static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
 {