Merge tag 'pm+acpi-3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI material from Rafael J Wysocki:
 "These are fixes (operating performance points library, cpufreq-dt
  driver, cpufreq core, ACPI backlight, cpupower tool), cleanups
  (cpuidle), new processor IDs for the RAPL (Running Average Power
  Limit) power capping driver, and a modification of the generic power
  domains framework allowing modular drivers to call one of its helper
  functions.

  Specifics:

   - Fix for a potential NULL pointer dereference in the cpufreq core
     due to an initialization race condition (Ethan Zhao).

   - Fixes for abuse of the OPP (Operating Performance Points) API
     related to RCU and other minor issues in the OPP library and the
     cpufreq-dt driver (Dmitry Torokhov).

   - cpuidle governors cleanup making them measure idle duration in a
     better way without using the CPUIDLE_FLAG_TIME_INVALID flag which
     allows that flag to be dropped from the ACPI cpuidle driver and
     from the core too (Len Brown).

   - New ACPI backlight blacklist entries for Samsung machines without a
     working native backlight interface that need to use the ACPI
     backlight instead (Aaron Lu).

   - New CPU IDs of future Intel Xeon CPUs for the Intel RAPL power
     capping driver (Jacob Pan).

   - Generic power domains framework modification to export the
     of_genpd_get_from_provider() function to modular drivers that will
     allow future driver modifications to be based on the mainline (Amit
     Daniel Kachhap).

   - Two fixes for the cpupower tool (Michal Privoznik, Prarit
     Bhargava)"

* tag 'pm+acpi-3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / video: Add some Samsung models to disable_native_backlight list
  tools / cpupower: Fix no idle state information return value
  tools / cpupower: Correctly detect if running as root
  cpufreq: fix a NULL pointer dereference in __cpufreq_governor()
  cpufreq-dt: defer probing if OPP table is not ready
  PM / OPP: take RCU lock in dev_pm_opp_get_opp_count
  PM / OPP: fix warning in of_free_opp_table()
  PM / OPP: add some lockdep annotations
  powercap / RAPL: add IDs for future Xeon CPUs
  PM / Domains: Export of_genpd_get_from_provider function
  cpuidle / ACPI: remove unused CPUIDLE_FLAG_TIME_INVALID
  cpuidle: ladder: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID
  cpuidle: menu: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID

1 files changed, 10 insertions, 15 deletions

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 659d7b0c9ebf..40580794e23d 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -396,8 +396,8 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	 * power state and occurrence of the wakeup event.
 	 *
 	 * If the entered idle state didn't support residency measurements,
-	 * we are basically lost in the dark how much time passed.
-	 * As a compromise, assume we slept for the whole expected time.
+	 * we use them anyway if they are short, and if long,
+	 * truncate to the whole expected time.
 	 *
 	 * Any measured amount of time will include the exit latency.
 	 * Since we are interested in when the wakeup begun, not when it
@@ -405,22 +405,17 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	 * the measured amount of time is less than the exit latency,
 	 * assume the state was never reached and the exit latency is 0.
 	 */
-	if (unlikely(target->flags & CPUIDLE_FLAG_TIME_INVALID)) {
-		/* Use timer value as is */
-		measured_us = data->next_timer_us;
 
-	} else {
-		/* Use measured value */
-		measured_us = cpuidle_get_last_residency(dev);
+	/* measured value */
+	measured_us = cpuidle_get_last_residency(dev);
 
-		/* Deduct exit latency */
-		if (measured_us > target->exit_latency)
-			measured_us -= target->exit_latency;
+	/* Deduct exit latency */
+	if (measured_us > target->exit_latency)
+		measured_us -= target->exit_latency;
 
-		/* Make sure our coefficients do not exceed unity */
-		if (measured_us > data->next_timer_us)
-			measured_us = data->next_timer_us;
-	}
+	/* Make sure our coefficients do not exceed unity */
+	if (measured_us > data->next_timer_us)
+		measured_us = data->next_timer_us;
 
 	/* Update our correction ratio */
 	new_factor = data->correction_factor[data->bucket];