Merge tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI updates from Rafael Wysocki:
 "From the number of commits perspective, the biggest items are ACPICA
  and cpufreq changes with the latter taking the lead (over 50 commits).

  On the cpufreq front, there are many cleanups and minor fixes in the
  core and governors, driver updates etc.  We also have a new cpufreq
  driver for Mediatek MT8173 chips.

  ACPICA mostly updates its debug infrastructure and adds a number of
  fixes and cleanups for a good measure.

  The Operating Performance Points (OPP) framework is updated with new
  DT bindings and support for them among other things.

  We have a few updates of the generic power domains framework and a
  reorganization of the ACPI device enumeration code and bus type
  operations.

  And a lot of fixes and cleanups all over.

  Included is one branch from the MFD tree as it contains some
  PM-related driver core and ACPI PM changes a few other commits are
  based on.

  Specifics:

   - ACPICA update to upstream revision 20150818 including method
     tracing extensions to allow more in-depth AML debugging in the
     kernel and a number of assorted fixes and cleanups (Bob Moore, Lv
     Zheng, Markus Elfring).

   - ACPI sysfs code updates and a documentation update related to AML
     method tracing (Lv Zheng).

   - ACPI EC driver fix related to serialized evaluations of _Qxx
     methods and ACPI tools updates allowing the EC userspace tool to be
     built from the kernel source (Lv Zheng).

   - ACPI processor driver updates preparing it for future introduction
     of CPPC support and ACPI PCC mailbox driver updates (Ashwin
     Chaugule).

   - ACPI interrupts enumeration fix for a regression related to the
     handling of IRQ attribute conflicts between MADT and the ACPI
     namespace (Jiang Liu).

   - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi
     Kasagar).

   - ACPI device registration code reorganization to separate the
     sysfs-related code and bus type operations from the rest (Rafael J
     Wysocki).

   - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
     Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).

   - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan
     Xinhui, Rafael J Wysocki).

   - cpufreq core cleanups on top of the previous changes allowing it to
     preseve its sysfs directories over system suspend/resume (Viresh
     Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).

   - cpufreq fixes and cleanups related to governors (Viresh Kumar).

   - cpufreq updates (core and the cpufreq-dt driver) related to the
     turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).

   - New DT bindings for Operating Performance Points (OPP), support for
     them in the OPP framework and in the cpufreq-dt driver plus related
     OPP framework fixes and cleanups (Viresh Kumar).

   - cpufreq powernv driver updates (Shilpasri G Bhat).

   - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).

   - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
     and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).

   - intel_pstate driver updates including Skylake-S support, support
     for enabling HW P-states per CPU and an additional vendor bypass
     list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).

   - cpuidle core fixes related to the handling of coupled idle states
     (Xunlei Pang).

   - intel_idle driver updates including Skylake Client support and
     support for freeze-mode-specific idle states (Len Brown).

   - Driver core updates related to power management (Andy Shevchenko,
     Rafael J Wysocki).

   - Generic power domains framework fixes and cleanups (Jon Hunter,
     Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).

   - Device PM QoS framework update to allow the latency tolerance
     setting to be exposed to user space via sysfs (Mika Westerberg).

   - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
     exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).

   - System sleep support updates (Alan Stern, Len Brown, SungEun Kim).

   - rockchip-io AVS support updates (Heiko Stuebner).

   - PM core clocks support fixup (Colin Ian King).

   - Power capping RAPL driver update including support for Skylake H/S
     and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).

   - Generic device properties framework fixes related to the handling
     of static (driver-provided) property sets (Andy Shevchenko).

   - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
     Shreyas B Prabhu)"

* tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits)
  cpufreq: speedstep-lib: Use monotonic clock
  cpufreq: powernv: Increase the verbosity of OCC console messages
  cpufreq: sfi: use kmemdup rather than duplicating its implementation
  cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor()
  cpufreq: rename cpufreq_real_policy as cpufreq_user_policy
  cpufreq: remove redundant 'policy' field from user_policy
  cpufreq: remove redundant 'governor' field from user_policy
  cpufreq: update user_policy.* on success
  cpufreq: use memcpy() to copy policy
  cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event
  cpufreq: mediatek: Add MT8173 cpufreq driver
  dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings
  PM / Domains: Fix typo in description of genpd_dev_pm_detach()
  PM / Domains: Remove unusable governor dummies
  PM / Domains: Make pm_genpd_init() available to modules
  PM / domains: Align column headers and data in pm_genpd_summary output
  powercap / RAPL: disable the 2nd power limit properly
  tools: cpupower: Fix error when running cpupower monitor
  PM / OPP: Drop unlikely before IS_ERR(_OR_NULL)
  PM / OPP: Fix static checker warning (broken 64bit big endian systems)
  ...

3 files changed, 27 insertions, 3 deletions

diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 9e302315e33d..02e8dfaa1ce2 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -18,6 +18,16 @@ config SUSPEND_FREEZER
 
 	  Turning OFF this setting is NOT recommended! If in doubt, say Y.
 
+config SUSPEND_SKIP_SYNC
+	bool "Skip kernel's sys_sync() on suspend to RAM/standby"
+	depends on SUSPEND
+	depends on EXPERT
+	help
+	  Skip the kernel sys_sync() before freezing user processes.
+	  Some systems prefer not to pay this cost on every invocation
+	  of suspend, or they are content with invoking sync() from
+	  user-space before invoking suspend.  Say Y if that's your case.
+
 config HIBERNATE_CALLBACKS
 	bool
 
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 53266b729fd9..7e4cda4a8dd9 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -484,11 +484,13 @@ static int enter_state(suspend_state_t state)
 	if (state == PM_SUSPEND_FREEZE)
 		freeze_begin();
 
+#ifndef CONFIG_SUSPEND_SKIP_SYNC
 	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
 	printk(KERN_INFO "PM: Syncing filesystems ... ");
 	sys_sync();
 	printk("done.\n");
 	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
+#endif
 
 	pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
 	error = suspend_prepare(state);
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
index 019069c84ff6..1896386e16bb 100644
--- a/kernel/power/wakelock.c
+++ b/kernel/power/wakelock.c
@@ -17,6 +17,7 @@
 #include <linux/list.h>
 #include <linux/rbtree.h>
 #include <linux/slab.h>
+#include <linux/workqueue.h>
 
 #include "power.h"
 
@@ -83,7 +84,9 @@ static inline void decrement_wakelocks_number(void) {}
 #define WL_GC_COUNT_MAX	100
 #define WL_GC_TIME_SEC	300
 
+static void __wakelocks_gc(struct work_struct *work);
 static LIST_HEAD(wakelocks_lru_list);
+static DECLARE_WORK(wakelock_work, __wakelocks_gc);
 static unsigned int wakelocks_gc_count;
 
 static inline void wakelocks_lru_add(struct wakelock *wl)
@@ -96,13 +99,12 @@ static inline void wakelocks_lru_most_recent(struct wakelock *wl)
 	list_move(&wl->lru, &wakelocks_lru_list);
 }
 
-static void wakelocks_gc(void)
+static void __wakelocks_gc(struct work_struct *work)
 {
 	struct wakelock *wl, *aux;
 	ktime_t now;
 
-	if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
-		return;
+	mutex_lock(&wakelocks_lock);
 
 	now = ktime_get();
 	list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
@@ -127,6 +129,16 @@ static void wakelocks_gc(void)
 		}
 	}
 	wakelocks_gc_count = 0;
+
+	mutex_unlock(&wakelocks_lock);
+}
+
+static void wakelocks_gc(void)
+{
+	if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
+		return;
+
+	schedule_work(&wakelock_work);
 }
 #else /* !CONFIG_PM_WAKELOCKS_GC */
 static inline void wakelocks_lru_add(struct wakelock *wl) {}