From ed1ac6e91a3ff7c561008ba57747cd6cbc49385e Mon Sep 17 00:00:00 2001
From: Tejun Heo
Date: Fri, 11 Jan 2013 13:37:33 +0100
Subject: PM: don't use [delayed_]work_pending()

There's no need to test whether a (delayed) work item is pending
before queueing, flushing or cancelling it, so remove work_pending()
tests used in those cases.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 kernel/power/autosleep.c | 2 +-
 kernel/power/qos.c       | 9 +++------
 2 files changed, 4 insertions(+), 7 deletions(-)

(limited to 'kernel/power')

diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c
index ca304046d9e2..c6422ffeda9a 100644
--- a/kernel/power/autosleep.c
+++ b/kernel/power/autosleep.c
@@ -66,7 +66,7 @@ static DECLARE_WORK(suspend_work, try_to_suspend);
 
 void queue_up_suspend_work(void)
 {
-	if (!work_pending(&suspend_work) && autosleep_state > PM_SUSPEND_ON)
+	if (autosleep_state > PM_SUSPEND_ON)
 		queue_work(autosleep_wq, &suspend_work);
 }
 
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 9322ff7eaad6..587dddeebf15 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -359,8 +359,7 @@ void pm_qos_update_request(struct pm_qos_request *req,
 		return;
 	}
 
-	if (delayed_work_pending(&req->work))
-		cancel_delayed_work_sync(&req->work);
+	cancel_delayed_work_sync(&req->work);
 
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
@@ -386,8 +385,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
 		 "%s called for unknown object.", __func__))
 		return;
 
-	if (delayed_work_pending(&req->work))
-		cancel_delayed_work_sync(&req->work);
+	cancel_delayed_work_sync(&req->work);
 
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
@@ -416,8 +414,7 @@ void pm_qos_remove_request(struct pm_qos_request *req)
 		return;
 	}
 
-	if (delayed_work_pending(&req->work))
-		cancel_delayed_work_sync(&req->work);
+	cancel_delayed_work_sync(&req->work);
 
 	pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
 			     &req->node, PM_QOS_REMOVE_REQ,
-- 
cgit v1.2.3


From 9f3b795a626ee79574595e06d1437fe0c7d51d29 Mon Sep 17 00:00:00 2001
From: Michał Mirosław
Date: Fri, 1 Feb 2013 20:40:17 +0100
Subject: driver-core: constify data for class_find_device()

All in-kernel users of class_find_device() don't really need mutable
data for match callback.

In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.

The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.

Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/class.c                |  4 ++--
 drivers/base/core.c                 |  4 ++--
 drivers/gpio/gpiolib.c              |  2 +-
 drivers/isdn/mISDN/core.c           |  4 ++--
 drivers/net/phy/mdio_bus.c          |  2 +-
 drivers/power/power_supply_core.c   |  4 ++--
 drivers/rtc/interface.c             |  6 +++---
 drivers/scsi/hosts.c                |  4 ++--
 drivers/scsi/osd/osd_uld.c          | 26 +++++++++-----------------
 drivers/scsi/scsi_transport_iscsi.c |  4 ++--
 drivers/spi/spi.c                   |  4 ++--
 drivers/uwb/lc-rc.c                 | 21 ++++++++++-----------
 include/linux/device.h              |  4 ++--
 include/linux/power_supply.h        |  2 +-
 include/linux/rtc.h                 |  2 +-
 init/do_mounts.c                    |  4 ++--
 kernel/power/suspend_test.c         | 11 +++++------
 net/ieee802154/wpan-class.c         |  5 ++---
 net/nfc/core.c                      |  4 ++--
 19 files changed, 53 insertions(+), 64 deletions(-)

(limited to 'kernel/power')

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 03243d4002fd..3ce845471327 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -420,8 +420,8 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
  * code.  There's no locking restriction.
  */
 struct device *class_find_device(struct class *class, struct device *start,
-				 void *data,
-				 int (*match)(struct device *, void *))
+				 const void *data,
+				 int (*match)(struct device *, const void *))
 {
 	struct class_dev_iter iter;
 	struct device *dev;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 27603a6c0a93..56536f4b0f6b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1617,9 +1617,9 @@ struct device *device_create(struct class *class, struct device *parent,
 }
 EXPORT_SYMBOL_GPL(device_create);
 
-static int __match_devt(struct device *dev, void *data)
+static int __match_devt(struct device *dev, const void *data)
 {
-	dev_t *devt = data;
+	const dev_t *devt = data;
 
 	return dev->devt == *devt;
 }
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 199fca15f270..5359ca78130f 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -806,7 +806,7 @@ fail_unlock:
 }
 EXPORT_SYMBOL_GPL(gpio_export);
 
-static int match_export(struct device *dev, void *data)
+static int match_export(struct device *dev, const void *data)
 {
 	return dev_get_drvdata(dev) == data;
 }
diff --git a/drivers/isdn/mISDN/core.c b/drivers/isdn/mISDN/core.c
index 3e245712bba7..da30c5cb9609 100644
--- a/drivers/isdn/mISDN/core.c
+++ b/drivers/isdn/mISDN/core.c
@@ -168,13 +168,13 @@ static struct class mISDN_class = {
 };
 
 static int
-_get_mdevice(struct device *dev, void *id)
+_get_mdevice(struct device *dev, const void *id)
 {
 	struct mISDNdevice *mdev = dev_to_mISDN(dev);
 
 	if (!mdev)
 		return 0;
-	if (mdev->id != *(u_int *)id)
+	if (mdev->id != *(const u_int *)id)
 		return 0;
 	return 1;
 }
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 044b5326459f..dc920974204e 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -95,7 +95,7 @@ static struct class mdio_bus_class = {
 
 #if IS_ENABLED(CONFIG_OF_MDIO)
 /* Helper function for of_mdio_find_bus */
-static int of_mdio_bus_match(struct device *dev, void *mdio_bus_np)
+static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
 {
 	return dev->of_node == mdio_bus_np;
 }
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 8a7cfb3cc166..5deac432e2ae 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -141,7 +141,7 @@ int power_supply_set_battery_charged(struct power_supply *psy)
 }
 EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);
 
-static int power_supply_match_device_by_name(struct device *dev, void *data)
+static int power_supply_match_device_by_name(struct device *dev, const void *data)
 {
 	const char *name = data;
 	struct power_supply *psy = dev_get_drvdata(dev);
@@ -149,7 +149,7 @@ static int power_supply_match_device_by_name(struct device *dev, void *data)
 	return strcmp(psy->name, name) == 0;
 }
 
-struct power_supply *power_supply_get_by_name(char *name)
+struct power_supply *power_supply_get_by_name(const char *name)
 {
 	struct device *dev = class_find_device(power_supply_class, NULL, name,
 					power_supply_match_device_by_name);
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 9592b936b71b..42bd57da239d 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -587,16 +587,16 @@ void rtc_update_irq(struct rtc_device *rtc,
 }
 EXPORT_SYMBOL_GPL(rtc_update_irq);
 
-static int __rtc_match(struct device *dev, void *data)
+static int __rtc_match(struct device *dev, const void *data)
 {
-	char *name = (char *)data;
+	const char *name = data;
 
 	if (strcmp(dev_name(dev), name) == 0)
 		return 1;
 	return 0;
 }
 
-struct rtc_device *rtc_class_open(char *name)
+struct rtc_device *rtc_class_open(const char *name)
 {
 	struct device *dev;
 	struct rtc_device *rtc = NULL;
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 593085a52275..df0c3c71ea43 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -468,10 +468,10 @@ void scsi_unregister(struct Scsi_Host *shost)
 }
 EXPORT_SYMBOL(scsi_unregister);
 
-static int __scsi_host_match(struct device *dev, void *data)
+static int __scsi_host_match(struct device *dev, const void *data)
 {
 	struct Scsi_Host *p;
-	unsigned short *hostnum = (unsigned short *)data;
+	const unsigned short *hostnum = data;
 
 	p = class_to_shost(dev);
 	return p->host_no == *hostnum;
diff --git a/drivers/scsi/osd/osd_uld.c b/drivers/scsi/osd/osd_uld.c
index 43754176a7b7..0fab6b5c7b82 100644
--- a/drivers/scsi/osd/osd_uld.c
+++ b/drivers/scsi/osd/osd_uld.c
@@ -268,18 +268,11 @@ static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,
 	return 0 == memcmp(a1, a2, a1_len);
 }
 
-struct find_oud_t {
-	const struct osd_dev_info *odi;
-	struct device *dev;
-	struct osd_uld_device *oud;
-} ;
-
-int _mach_odi(struct device *dev, void *find_data)
+static int _match_odi(struct device *dev, const void *find_data)
 {
 	struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
 						  class_dev);
-	struct find_oud_t *fot = find_data;
-	const struct osd_dev_info *odi = fot->odi;
+	const struct osd_dev_info *odi = find_data;
 
 	if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
 			      odi->systemid, odi->systemid_len) &&
@@ -287,7 +280,6 @@ int _mach_odi(struct device *dev, void *find_data)
 			      odi->osdname, odi->osdname_len)) {
 		OSD_DEBUG("found device sysid_len=%d osdname=%d\n",
 			  odi->systemid_len, odi->osdname_len);
-		fot->oud = oud;
 		return 1;
 	} else {
 		return 0;
@@ -301,19 +293,19 @@ int _mach_odi(struct device *dev, void *find_data)
  */
 struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)
 {
-	struct find_oud_t find = {.odi = odi};
-
-	find.dev = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);
-	if (likely(find.dev)) {
+	struct device *dev = class_find_device(&osd_uld_class, NULL, odi, _match_odi);
+	if (likely(dev)) {
 		struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
+		struct osd_uld_device *oud = container_of(dev,
+			struct osd_uld_device, class_dev);
 
 		if (unlikely(!odh)) {
-			put_device(find.dev);
+			put_device(dev);
 			return ERR_PTR(-ENOMEM);
 		}
 
-		odh->od = find.oud->od;
-		odh->oud = find.oud;
+		odh->od = oud->od;
+		odh->oud = oud;
 
 		return &odh->od;
 	}
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 31969f2e13ce..59d427bf08e2 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -183,10 +183,10 @@ static struct attribute_group iscsi_endpoint_group = {
 
 #define ISCSI_MAX_EPID -1
 
-static int iscsi_match_epid(struct device *dev, void *data)
+static int iscsi_match_epid(struct device *dev, const void *data)
 {
 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
-	uint64_t *epid = (uint64_t *) data;
+	const uint64_t *epid = data;
 
 	return *epid == ep->id;
 }
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 19ee901577da..493ce4a71717 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1248,10 +1248,10 @@ int spi_master_resume(struct spi_master *master)
 }
 EXPORT_SYMBOL_GPL(spi_master_resume);
 
-static int __spi_master_match(struct device *dev, void *data)
+static int __spi_master_match(struct device *dev, const void *data)
 {
 	struct spi_master *m;
-	u16 *bus_num = data;
+	const u16 *bus_num = data;
 
 	m = container_of(dev, struct spi_master, dev);
 	return m->bus_num == *bus_num;
diff --git a/drivers/uwb/lc-rc.c b/drivers/uwb/lc-rc.c
index 4d688c750801..3eca6ceb9844 100644
--- a/drivers/uwb/lc-rc.c
+++ b/drivers/uwb/lc-rc.c
@@ -40,9 +40,9 @@
 
 #include "uwb-internal.h"
 
-static int uwb_rc_index_match(struct device *dev, void *data)
+static int uwb_rc_index_match(struct device *dev, const void *data)
 {
-	int *index = data;
+	const int *index = data;
 	struct uwb_rc *rc = dev_get_drvdata(dev);
 
 	if (rc->index == *index)
@@ -334,9 +334,9 @@ void uwb_rc_rm(struct uwb_rc *rc)
 }
 EXPORT_SYMBOL_GPL(uwb_rc_rm);
 
-static int find_rc_try_get(struct device *dev, void *data)
+static int find_rc_try_get(struct device *dev, const void *data)
 {
-	struct uwb_rc *target_rc = data;
+	const struct uwb_rc *target_rc = data;
 	struct uwb_rc *rc = dev_get_drvdata(dev);
 
 	if (rc == NULL) {
@@ -386,9 +386,9 @@ static inline struct uwb_rc *uwb_rc_get(struct uwb_rc *rc)
 	return rc;
 }
 
-static int find_rc_grandpa(struct device *dev, void *data)
+static int find_rc_grandpa(struct device *dev, const void *data)
 {
-	struct device *grandpa_dev = data;
+	const struct device *grandpa_dev = data;
 	struct uwb_rc *rc = dev_get_drvdata(dev);
 
 	if (rc->uwb_dev.dev.parent->parent == grandpa_dev) {
@@ -419,7 +419,7 @@ struct uwb_rc *uwb_rc_get_by_grandpa(const struct device *grandpa_dev)
 	struct device *dev;
 	struct uwb_rc *rc = NULL;
 
-	dev = class_find_device(&uwb_rc_class, NULL, (void *)grandpa_dev,
+	dev = class_find_device(&uwb_rc_class, NULL, grandpa_dev,
 				find_rc_grandpa);
 	if (dev)
 		rc = dev_get_drvdata(dev);
@@ -432,9 +432,9 @@ EXPORT_SYMBOL_GPL(uwb_rc_get_by_grandpa);
  *
  * @returns the pointer to the radio controller, properly referenced
  */
-static int find_rc_dev(struct device *dev, void *data)
+static int find_rc_dev(struct device *dev, const void *data)
 {
-	struct uwb_dev_addr *addr = data;
+	const struct uwb_dev_addr *addr = data;
 	struct uwb_rc *rc = dev_get_drvdata(dev);
 
 	if (rc == NULL) {
@@ -453,8 +453,7 @@ struct uwb_rc *uwb_rc_get_by_dev(const struct uwb_dev_addr *addr)
 	struct device *dev;
 	struct uwb_rc *rc = NULL;
 
-	dev = class_find_device(&uwb_rc_class, NULL, (void *)addr,
-				find_rc_dev);
+	dev = class_find_device(&uwb_rc_class, NULL, addr, find_rc_dev);
 	if (dev)
 		rc = dev_get_drvdata(dev);
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 251f33b21ef9..a089676084a5 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -395,8 +395,8 @@ extern int class_for_each_device(struct class *class, struct device *start,
 				 void *data,
 				 int (*fn)(struct device *dev, void *data));
 extern struct device *class_find_device(struct class *class,
-					struct device *start, void *data,
-					int (*match)(struct device *, void *));
+					struct device *start, const void *data,
+					int (*match)(struct device *, const void *));
 
 struct class_attribute {
 	struct attribute attr;
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 1f0ab90aff00..86ecaa679ded 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -224,7 +224,7 @@ struct power_supply_info {
 	int use_for_apm;
 };
 
-extern struct power_supply *power_supply_get_by_name(char *name);
+extern struct power_supply *power_supply_get_by_name(const char *name);
 extern void power_supply_changed(struct power_supply *psy);
 extern int power_supply_am_i_supplied(struct power_supply *psy);
 extern int power_supply_set_battery_charged(struct power_supply *psy);
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 9531845c419f..445fe6e7c629 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -148,7 +148,7 @@ extern int rtc_initialize_alarm(struct rtc_device *rtc,
 extern void rtc_update_irq(struct rtc_device *rtc,
 			unsigned long num, unsigned long events);
 
-extern struct rtc_device *rtc_class_open(char *name);
+extern struct rtc_device *rtc_class_open(const char *name);
 extern void rtc_class_close(struct rtc_device *rtc);
 
 extern int rtc_irq_register(struct rtc_device *rtc,
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 1d1b6348f903..a2b49f2c1bd8 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -81,9 +81,9 @@ struct uuidcmp {
  *
  * Returns 1 if the device matches, and 0 otherwise.
  */
-static int match_dev_by_uuid(struct device *dev, void *data)
+static int match_dev_by_uuid(struct device *dev, const void *data)
 {
-	struct uuidcmp *cmp = data;
+	const struct uuidcmp *cmp = data;
 	struct hd_struct *part = dev_to_part(dev);
 
 	if (!part->info)
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 25596e450ac7..9b2a1d58558d 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -112,7 +112,7 @@ static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
 	rtc_set_alarm(rtc, &alm);
 }
 
-static int __init has_wakealarm(struct device *dev, void *name_ptr)
+static int __init has_wakealarm(struct device *dev, const void *data)
 {
 	struct rtc_device *candidate = to_rtc_device(dev);
 
@@ -121,7 +121,6 @@ static int __init has_wakealarm(struct device *dev, void *name_ptr)
 	if (!device_may_wakeup(candidate->dev.parent))
 		return 0;
 
-	*(const char **)name_ptr = dev_name(dev);
 	return 1;
 }
 
@@ -159,8 +158,8 @@ static int __init test_suspend(void)
 	static char		warn_no_rtc[] __initdata =
 		KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
 
-	char			*pony = NULL;
 	struct rtc_device	*rtc = NULL;
+	struct device		*dev;
 
 	/* PM is initialized by now; is that state testable? */
 	if (test_state == PM_SUSPEND_ON)
@@ -171,9 +170,9 @@ static int __init test_suspend(void)
 	}
 
 	/* RTCs have initialized by now too ... can we use one? */
-	class_find_device(rtc_class, NULL, &pony, has_wakealarm);
-	if (pony)
-		rtc = rtc_class_open(pony);
+	dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm);
+	if (dev)
+		rtc = rtc_class_open(dev_name(dev));
 	if (!rtc) {
 		printk(warn_no_rtc);
 		goto done;
diff --git a/net/ieee802154/wpan-class.c b/net/ieee802154/wpan-class.c
index 1627ef2e8522..13571eae6bae 100644
--- a/net/ieee802154/wpan-class.c
+++ b/net/ieee802154/wpan-class.c
@@ -91,7 +91,7 @@ static struct class wpan_phy_class = {
 static DEFINE_MUTEX(wpan_phy_mutex);
 static int wpan_phy_idx;
 
-static int wpan_phy_match(struct device *dev, void *data)
+static int wpan_phy_match(struct device *dev, const void *data)
 {
 	return !strcmp(dev_name(dev), (const char *)data);
 }
@@ -103,8 +103,7 @@ struct wpan_phy *wpan_phy_find(const char *str)
 	if (WARN_ON(!str))
 		return NULL;
 
-	dev = class_find_device(&wpan_phy_class, NULL,
-			(void *)str, wpan_phy_match);
+	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
 	if (!dev)
 		return NULL;
 
diff --git a/net/nfc/core.c b/net/nfc/core.c
index aa64ea441676..0f4a6de6f161 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -734,10 +734,10 @@ struct class nfc_class = {
 };
 EXPORT_SYMBOL(nfc_class);
 
-static int match_idx(struct device *d, void *data)
+static int match_idx(struct device *d, const void *data)
 {
 	struct nfc_dev *dev = to_nfc_dev(d);
-	unsigned int *idx = data;
+	const unsigned int *idx = data;
 
 	return dev->idx == *idx;
 }
-- 
cgit v1.2.3


From 7e73c5ae6e7991a6c01f6d096ff8afaef4458c36 Mon Sep 17 00:00:00 2001
From: Zhang Rui
Date: Wed, 6 Feb 2013 13:00:36 +0100
Subject: PM: Introduce suspend state PM_SUSPEND_FREEZE

PM_SUSPEND_FREEZE state is a general state that
does not need any platform specific support, it equals
frozen processes + suspended devices + idle processors.

Compared with PM_SUSPEND_MEMORY,
PM_SUSPEND_FREEZE saves less power
because the system is still in a running state.
PM_SUSPEND_FREEZE has less resume latency because it does not
touch BIOS, and the processors are in idle state.

Compared with RTPM/idle,
PM_SUSPEND_FREEZE saves more power as
1. the processor has longer sleep time because processes are frozen.
   The deeper c-state the processor supports, more power saving we can get.
2. PM_SUSPEND_FREEZE uses system suspend code path, thus we can get
   more power saving from the devices that does not have good RTPM support.

This state is useful for
1) platforms that do not have STR, or have a broken STR.
2) platforms that have an extremely low power idle state,
   which can be used to replace STR.

The following describes how PM_SUSPEND_FREEZE state works.
1. echo freeze > /sys/power/state
2. the processes are frozen.
3. all the devices are suspended.
4. all the processors are blocked by a wait queue
5. all the processors idles and enters (Deep) c-state.
6. an interrupt fires.
7. a processor is woken up and handles the irq.
8. if it is a general event,
   a) the irq handler runs and quites.
   b) goto step 4.
9. if it is a real wake event, say, power button pressing, keyboard touch, mouse moving,
   a) the irq handler runs and activate the wakeup source
   b) wakeup_source_activate() notifies the wait queue.
   c) system starts resuming from PM_SUSPEND_FREEZE
10. all the devices are resumed.
11. all the processes are unfrozen.
12. system is back to working.

Known Issue:
The wakeup of this new PM_SUSPEND_FREEZE state may behave differently
from the previous suspend state.
Take ACPI platform for example, there are some GPEs that only enabled
when the system is in sleep state, to wake the system backk from S3/S4.
But we are not touching these GPEs during transition to PM_SUSPEND_FREEZE.
This means we may lose some wake event.
But on the other hand, as we do not disable all the Interrupts during
PM_SUSPEND_FREEZE, we may get some extra "wakeup" Interrupts, that are
not available for S3/S4.

The patches has been tested on an old Sony laptop, and here are the results:

Average Power:
1. RPTM/idle for half an hour:
   14.8W, 12.6W, 14.1W, 12.5W, 14.4W, 13.2W, 12.9W
2. Freeze for half an hour:
   11W, 10.4W, 9.4W, 11.3W 10.5W
3. RTPM/idle for three hours:
   11.6W
4. Freeze for three hours:
   10W
5. Suspend to Memory:
   0.5~0.9W

Average Resume Latency:
1. RTPM/idle with a black screen: (From pressing keyboard to screen back)
   Less than 0.2s
2. Freeze: (From pressing power button to screen back)
   2.50s
3. Suspend to Memory: (From pressing power button to screen back)
   4.33s

>From the results, we can see that all the platforms should benefit from
this patch, even if it does not have Low Power S0.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/base/power/wakeup.c |  6 ++++
 include/linux/suspend.h     |  6 +++-
 kernel/power/main.c         |  2 +-
 kernel/power/suspend.c      | 69 ++++++++++++++++++++++++++++++++++++---------
 4 files changed, 68 insertions(+), 15 deletions(-)

(limited to 'kernel/power')

diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index e6ee5e80e546..79715e7fa43e 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -382,6 +382,12 @@ static void wakeup_source_activate(struct wakeup_source *ws)
 {
 	unsigned int cec;
 
+	/*
+	 * active wakeup source should bring the system
+	 * out of PM_SUSPEND_FREEZE state
+	 */
+	freeze_wake();
+
 	ws->active = true;
 	ws->active_count++;
 	ws->last_time = ktime_get();
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 0c808d7fa579..d4e3f16d5e89 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -34,8 +34,10 @@ static inline void pm_restore_console(void)
 typedef int __bitwise suspend_state_t;
 
 #define PM_SUSPEND_ON		((__force suspend_state_t) 0)
-#define PM_SUSPEND_STANDBY	((__force suspend_state_t) 1)
+#define PM_SUSPEND_FREEZE	((__force suspend_state_t) 1)
+#define PM_SUSPEND_STANDBY	((__force suspend_state_t) 2)
 #define PM_SUSPEND_MEM		((__force suspend_state_t) 3)
+#define PM_SUSPEND_MIN		PM_SUSPEND_FREEZE
 #define PM_SUSPEND_MAX		((__force suspend_state_t) 4)
 
 enum suspend_stat_step {
@@ -192,6 +194,7 @@ struct platform_suspend_ops {
  */
 extern void suspend_set_ops(const struct platform_suspend_ops *ops);
 extern int suspend_valid_only_mem(suspend_state_t state);
+extern void freeze_wake(void);
 
 /**
  * arch_suspend_disable_irqs - disable IRQs for suspend
@@ -217,6 +220,7 @@ extern int pm_suspend(suspend_state_t state);
 
 static inline void suspend_set_ops(const struct platform_suspend_ops *ops) {}
 static inline int pm_suspend(suspend_state_t state) { return -ENOSYS; }
+static inline void freeze_wake(void) {}
 #endif /* !CONFIG_SUSPEND */
 
 /* struct pbe is used for creating lists of pages that should be restored
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 1c16f9167de1..b1c26a92ca9f 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -313,7 +313,7 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 static suspend_state_t decode_state(const char *buf, size_t n)
 {
 #ifdef CONFIG_SUSPEND
-	suspend_state_t state = PM_SUSPEND_STANDBY;
+	suspend_state_t state = PM_SUSPEND_MIN;
 	const char * const *s;
 #endif
 	char *p;
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index c8b7446b27df..d4feda084a3a 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -30,12 +30,38 @@
 #include "power.h"
 
 const char *const pm_states[PM_SUSPEND_MAX] = {
+	[PM_SUSPEND_FREEZE]	= "freeze",
 	[PM_SUSPEND_STANDBY]	= "standby",
 	[PM_SUSPEND_MEM]	= "mem",
 };
 
 static const struct platform_suspend_ops *suspend_ops;
 
+static bool need_suspend_ops(suspend_state_t state)
+{
+	return !!(state > PM_SUSPEND_FREEZE);
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
+static bool suspend_freeze_wake;
+
+static void freeze_begin(void)
+{
+	suspend_freeze_wake = false;
+}
+
+static void freeze_enter(void)
+{
+	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
+}
+
+void freeze_wake(void)
+{
+	suspend_freeze_wake = true;
+	wake_up(&suspend_freeze_wait_head);
+}
+EXPORT_SYMBOL_GPL(freeze_wake);
+
 /**
  * suspend_set_ops - Set the global suspend method table.
  * @ops: Suspend operations to use.
@@ -50,8 +76,11 @@ EXPORT_SYMBOL_GPL(suspend_set_ops);
 
 bool valid_state(suspend_state_t state)
 {
+	if (state == PM_SUSPEND_FREEZE)
+		return true;
 	/*
-	 * All states need lowlevel support and need to be valid to the lowlevel
+	 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
+	 * support and need to be valid to the lowlevel
 	 * implementation, no valid callback implies that none are valid.
 	 */
 	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
@@ -89,11 +118,11 @@ static int suspend_test(int level)
  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
  * freeze processes.
  */
-static int suspend_prepare(void)
+static int suspend_prepare(suspend_state_t state)
 {
 	int error;
 
-	if (!suspend_ops || !suspend_ops->enter)
+	if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
 		return -EPERM;
 
 	pm_prepare_console();
@@ -137,7 +166,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 {
 	int error;
 
-	if (suspend_ops->prepare) {
+	if (need_suspend_ops(state) && suspend_ops->prepare) {
 		error = suspend_ops->prepare();
 		if (error)
 			goto Platform_finish;
@@ -149,12 +178,23 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 		goto Platform_finish;
 	}
 
-	if (suspend_ops->prepare_late) {
+	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
 		error = suspend_ops->prepare_late();
 		if (error)
 			goto Platform_wake;
 	}
 
+	/*
+	 * PM_SUSPEND_FREEZE equals
+	 * frozen processes + suspended devices + idle processors.
+	 * Thus we should invoke freeze_enter() soon after
+	 * all the devices are suspended.
+	 */
+	if (state == PM_SUSPEND_FREEZE) {
+		freeze_enter();
+		goto Platform_wake;
+	}
+
 	if (suspend_test(TEST_PLATFORM))
 		goto Platform_wake;
 
@@ -182,13 +222,13 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	enable_nonboot_cpus();
 
  Platform_wake:
-	if (suspend_ops->wake)
+	if (need_suspend_ops(state) && suspend_ops->wake)
 		suspend_ops->wake();
 
 	dpm_resume_start(PMSG_RESUME);
 
  Platform_finish:
-	if (suspend_ops->finish)
+	if (need_suspend_ops(state) && suspend_ops->finish)
 		suspend_ops->finish();
 
 	return error;
@@ -203,11 +243,11 @@ int suspend_devices_and_enter(suspend_state_t state)
 	int error;
 	bool wakeup = false;
 
-	if (!suspend_ops)
+	if (need_suspend_ops(state) && !suspend_ops)
 		return -ENOSYS;
 
 	trace_machine_suspend(state);
-	if (suspend_ops->begin) {
+	if (need_suspend_ops(state) && suspend_ops->begin) {
 		error = suspend_ops->begin(state);
 		if (error)
 			goto Close;
@@ -226,7 +266,7 @@ int suspend_devices_and_enter(suspend_state_t state)
 
 	do {
 		error = suspend_enter(state, &wakeup);
-	} while (!error && !wakeup
+	} while (!error && !wakeup && need_suspend_ops(state)
 		&& suspend_ops->suspend_again && suspend_ops->suspend_again());
 
  Resume_devices:
@@ -236,13 +276,13 @@ int suspend_devices_and_enter(suspend_state_t state)
 	ftrace_start();
 	resume_console();
  Close:
-	if (suspend_ops->end)
+	if (need_suspend_ops(state) && suspend_ops->end)
 		suspend_ops->end();
 	trace_machine_suspend(PWR_EVENT_EXIT);
 	return error;
 
  Recover_platform:
-	if (suspend_ops->recover)
+	if (need_suspend_ops(state) && suspend_ops->recover)
 		suspend_ops->recover();
 	goto Resume_devices;
 }
@@ -278,12 +318,15 @@ static int enter_state(suspend_state_t state)
 	if (!mutex_trylock(&pm_mutex))
 		return -EBUSY;
 
+	if (state == PM_SUSPEND_FREEZE)
+		freeze_begin();
+
 	printk(KERN_INFO "PM: Syncing filesystems ... ");
 	sys_sync();
 	printk("done.\n");
 
 	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
-	error = suspend_prepare();
+	error = suspend_prepare(state);
 	if (error)
 		goto Unlock;
 
-- 
cgit v1.2.3


From 957d1282bb8c07e682e142b9237cd9fcb8348a0b Mon Sep 17 00:00:00 2001
From: Li Fei
Date: Fri, 1 Feb 2013 08:56:03 +0000
Subject: suspend: enable freeze timeout configuration through sys

At present, the value of timeout for freezing is 20s, which is
meaningless in case that one thread is frozen with mutex locked
and another thread is trying to lock the mutex, as this time of
freezing will fail unavoidably.
And if there is no new wakeup event registered, the system will
waste at most 20s for such meaningless trying of freezing.

With this patch, the value of timeout can be configured to smaller
value, so such meaningless trying of freezing will be aborted in
earlier time, and later freezing can be also triggered in earlier
time. And more power will be saved.
In normal case on mobile phone, it costs real little time to freeze
processes. On some platform, it only costs about 20ms to freeze
user space processes and 10ms to freeze kernel freezable threads.

Signed-off-by: Liu Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Li Fei <fei.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 Documentation/power/freezing-of-tasks.txt |  5 +++++
 include/linux/freezer.h                   |  5 +++++
 kernel/power/main.c                       | 27 +++++++++++++++++++++++++++
 kernel/power/process.c                    |  4 ++--
 4 files changed, 39 insertions(+), 2 deletions(-)

(limited to 'kernel/power')

diff --git a/Documentation/power/freezing-of-tasks.txt b/Documentation/power/freezing-of-tasks.txt
index 6ec291ea1c78..85894d83b352 100644
--- a/Documentation/power/freezing-of-tasks.txt
+++ b/Documentation/power/freezing-of-tasks.txt
@@ -223,3 +223,8 @@ since they ask the freezer to skip freezing this task, since it is anyway
 only after the entire suspend/hibernation sequence is complete.
 So, to summarize, use [un]lock_system_sleep() instead of directly using
 mutex_[un]lock(&pm_mutex). That would prevent freezing failures.
+
+V. Miscellaneous
+/sys/power/pm_freeze_timeout controls how long it will cost at most to freeze
+all user space processes or all freezable kernel threads, in unit of millisecond.
+The default value is 20000, with range of unsigned integer.
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index e4238ceaa4d6..e70df40d84f6 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -12,6 +12,11 @@ extern atomic_t system_freezing_cnt;	/* nr of freezing conds in effect */
 extern bool pm_freezing;		/* PM freezing in effect */
 extern bool pm_nosig_freezing;		/* PM nosig freezing in effect */
 
+/*
+ * Timeout for stopping processes
+ */
+extern unsigned int freeze_timeout_msecs;
+
 /*
  * Check if a process has been frozen
  */
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b1c26a92ca9f..d77663bfedeb 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -553,6 +553,30 @@ power_attr(pm_trace_dev_match);
 
 #endif /* CONFIG_PM_TRACE */
 
+#ifdef CONFIG_FREEZER
+static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
+				      struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%u\n", freeze_timeout_msecs);
+}
+
+static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
+				       struct kobj_attribute *attr,
+				       const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	freeze_timeout_msecs = val;
+	return n;
+}
+
+power_attr(pm_freeze_timeout);
+
+#endif	/* CONFIG_FREEZER*/
+
 static struct attribute * g[] = {
 	&state_attr.attr,
 #ifdef CONFIG_PM_TRACE
@@ -575,6 +599,9 @@ static struct attribute * g[] = {
 #ifdef CONFIG_PM_SLEEP_DEBUG
 	&pm_print_times_attr.attr,
 #endif
+#endif
+#ifdef CONFIG_FREEZER
+	&pm_freeze_timeout_attr.attr,
 #endif
 	NULL,
 };
diff --git a/kernel/power/process.c b/kernel/power/process.c
index d5a258b60c6f..98088e0e71e8 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -21,7 +21,7 @@
 /* 
  * Timeout for stopping processes
  */
-#define TIMEOUT	(20 * HZ)
+unsigned int __read_mostly freeze_timeout_msecs = 20 * MSEC_PER_SEC;
 
 static int try_to_freeze_tasks(bool user_only)
 {
@@ -36,7 +36,7 @@ static int try_to_freeze_tasks(bool user_only)
 
 	do_gettimeofday(&start);
 
-	end_time = jiffies + TIMEOUT;
+	end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);
 
 	if (!user_only)
 		freeze_workqueues_begin();
-- 
cgit v1.2.3