Merge tag 'pm+acpi-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael J Wysocki:

 - Two fixes for the new intel_pstate driver from Dirk Brandewie.

 - Fix for incorrect usage of the .find_bridge() callback from struct
   acpi_bus_type in the USB core and subsequent removal of that callback
   from Rafael J Wysocki.

 - ACPI processor driver cleanups from Chen Gang and Syam Sidhardhan.

 - ACPI initialization and error messages fix from Joe Perches.

 - Operating Performance Points documentation improvement from Nishanth
   Menon.

 - Fixes for memory leaks and potential concurrency issues and sysfs
  attributes leaks during device removal in the core device PM QoS code
  from Rafael J Wysocki.

 - Calxeda Highbank cpufreq driver simplification from Emilio López.

 - cpufreq comment cleanup from Namhyung Kim.

 - Fix for a section mismatch in Calxeda Highbank interprocessor
   communication code from Mark Langsdorf (this is not a PM fix strictly
   speaking, but the code in question went in through the PM tree).

* tag 'pm+acpi-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq / intel_pstate: Do not load on VM that does not report max P state.
  cpufreq / intel_pstate: Fix intel_pstate_init() error path
  ACPI / glue: Drop .find_bridge() callback from struct acpi_bus_type
  ACPI / glue: Add .match() callback to struct acpi_bus_type
  ACPI / porocessor: Beautify code, pr->id is u32 which is never < 0
  ACPI / processor: Remove redundant NULL check before kfree
  ACPI / Sleep: Avoid interleaved message on errors
  PM / QoS: Remove device PM QoS sysfs attributes at the right place
  PM / QoS: Fix concurrency issues and memory leaks in device PM QoS
  cpufreq: highbank: do not initialize array with a loop
  PM / OPP: improve introductory documentation
  cpufreq: Fix a typo in comment
  mailbox, pl320-ipc: remove __init from probe function

19 files changed, 215 insertions, 214 deletions

diff --git a/Documentation/power/opp.txt b/Documentation/power/opp.txt
index 3035d00757a..425c51d56ae 100644
--- a/Documentation/power/opp.txt
+++ b/Documentation/power/opp.txt
@@ -1,6 +1,5 @@
-*=============*
-* OPP Library *
-*=============*
+Operating Performance Points (OPP) Library
+==========================================
 
 (C) 2009-2010 Nishanth Menon <nm@ti.com>, Texas Instruments Incorporated
 
@@ -16,15 +15,31 @@ Contents
 
 1. Introduction
 ===============
+1.1 What is an Operating Performance Point (OPP)?
+
 Complex SoCs of today consists of a multiple sub-modules working in conjunction.
 In an operational system executing varied use cases, not all modules in the SoC
 need to function at their highest performing frequency all the time. To
 facilitate this, sub-modules in a SoC are grouped into domains, allowing some
-domains to run at lower voltage and frequency while other domains are loaded
-more. The set of discrete tuples consisting of frequency and voltage pairs that
+domains to run at lower voltage and frequency while other domains run at
+voltage/frequency pairs that are higher.
+
+The set of discrete tuples consisting of frequency and voltage pairs that
 the device will support per domain are called Operating Performance Points or
 OPPs.
 
+As an example:
+Let us consider an MPU device which supports the following:
+{300MHz at minimum voltage of 1V}, {800MHz at minimum voltage of 1.2V},
+{1GHz at minimum voltage of 1.3V}
+
+We can represent these as three OPPs as the following {Hz, uV} tuples:
+{300000000, 1000000}
+{800000000, 1200000}
+{1000000000, 1300000}
+
+1.2 Operating Performance Points Library
+
 OPP library provides a set of helper functions to organize and query the OPP
 information. The library is located in drivers/base/power/opp.c and the header
 is located in include/linux/opp.h. OPP library can be enabled by enabling
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index ef6f155469b..40a84cc6740 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -36,12 +36,11 @@ int register_acpi_bus_type(struct acpi_bus_type *type)
 {
 	if (acpi_disabled)
 		return -ENODEV;
-	if (type && type->bus && type->find_device) {
+	if (type && type->match && type->find_device) {
 		down_write(&bus_type_sem);
 		list_add_tail(&type->list, &bus_type_list);
 		up_write(&bus_type_sem);
-		printk(KERN_INFO PREFIX "bus type %s registered\n",
-		       type->bus->name);
+		printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
 		return 0;
 	}
 	return -ENODEV;
@@ -56,24 +55,21 @@ int unregister_acpi_bus_type(struct acpi_bus_type *type)
 		down_write(&bus_type_sem);
 		list_del_init(&type->list);
 		up_write(&bus_type_sem);
-		printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
-		       type->bus->name);
+		printk(KERN_INFO PREFIX "bus type %s unregistered\n",
+		       type->name);
 		return 0;
 	}
 	return -ENODEV;
 }
 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
 
-static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
+static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
 {
 	struct acpi_bus_type *tmp, *ret = NULL;
 
-	if (!type)
-		return NULL;
-
 	down_read(&bus_type_sem);
 	list_for_each_entry(tmp, &bus_type_list, list) {
-		if (tmp->bus == type) {
+		if (tmp->match(dev)) {
 			ret = tmp;
 			break;
 		}
@@ -82,22 +78,6 @@ static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
 	return ret;
 }
 
-static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
-{
-	struct acpi_bus_type *tmp;
-	int ret = -ENODEV;
-
-	down_read(&bus_type_sem);
-	list_for_each_entry(tmp, &bus_type_list, list) {
-		if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
-			ret = 0;
-			break;
-		}
-	}
-	up_read(&bus_type_sem);
-	return ret;
-}
-
 static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used,
 				      void *addr_p, void **ret_p)
 {
@@ -261,29 +241,12 @@ err:
 
 static int acpi_platform_notify(struct device *dev)
 {
-	struct acpi_bus_type *type;
+	struct acpi_bus_type *type = acpi_get_bus_type(dev);
 	acpi_handle handle;
 	int ret;
 
 	ret = acpi_bind_one(dev, NULL);
-	if (ret && (!dev->bus || !dev->parent)) {
-		/* bridge devices genernally haven't bus or parent */
-		ret = acpi_find_bridge_device(dev, &handle);
-		if (!ret) {
-			ret = acpi_bind_one(dev, handle);
-			if (ret)
-				goto out;
-		}
-	}
-
-	type = acpi_get_bus_type(dev->bus);
-	if (ret) {
-		if (!type || !type->find_device) {
-			DBG("No ACPI bus support for %s\n", dev_name(dev));
-			ret = -EINVAL;
-			goto out;
-		}
-
+	if (ret && type) {
 		ret = type->find_device(dev, &handle);
 		if (ret) {
 			DBG("Unable to get handle for %s\n", dev_name(dev));
@@ -316,7 +279,7 @@ static int acpi_platform_notify_remove(struct device *dev)
 {
 	struct acpi_bus_type *type;
 
-	type = acpi_get_bus_type(dev->bus);
+	type = acpi_get_bus_type(dev);
 	if (type && type->cleanup)
 		type->cleanup(dev);
 
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index eff722278ff..164d49569ae 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -158,8 +158,7 @@ static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
 	}
 
 exit:
-	if (buffer.pointer)
-		kfree(buffer.pointer);
+	kfree(buffer.pointer);
 	return apic_id;
 }
 
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index df34bd04ae6..bec717ffd25 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -559,7 +559,7 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device)
 		return 0;
 #endif
 
-	BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
+	BUG_ON(pr->id >= nr_cpu_ids);
 
 	/*
 	 * Buggy BIOS check
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 6d3a06a629a..24213033fba 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -599,7 +599,6 @@ static void acpi_sleep_suspend_setup(void)
 		status = acpi_get_sleep_type_data(i, &type_a, &type_b);
 		if (ACPI_SUCCESS(status)) {
 			sleep_states[i] = 1;
-			pr_cont(" S%d", i);
 		}
 	}
 
@@ -742,7 +741,6 @@ static void acpi_sleep_hibernate_setup(void)
 	hibernation_set_ops(old_suspend_ordering ?
 			&acpi_hibernation_ops_old : &acpi_hibernation_ops);
 	sleep_states[ACPI_STATE_S4] = 1;
-	pr_cont(KERN_CONT " S4");
 	if (nosigcheck)
 		return;
 
@@ -788,6 +786,9 @@ int __init acpi_sleep_init(void)
 {
 	acpi_status status;
 	u8 type_a, type_b;
+	char supported[ACPI_S_STATE_COUNT * 3 + 1];
+	char *pos = supported;
+	int i;
 
 	if (acpi_disabled)
 		return 0;
@@ -795,7 +796,6 @@ int __init acpi_sleep_init(void)
 	acpi_sleep_dmi_check();
 
 	sleep_states[ACPI_STATE_S0] = 1;
-	pr_info(PREFIX "(supports S0");
 
 	acpi_sleep_suspend_setup();
 	acpi_sleep_hibernate_setup();
@@ -803,11 +803,17 @@ int __init acpi_sleep_init(void)
 	status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
 	if (ACPI_SUCCESS(status)) {
 		sleep_states[ACPI_STATE_S5] = 1;
-		pr_cont(" S5");
 		pm_power_off_prepare = acpi_power_off_prepare;
 		pm_power_off = acpi_power_off;
 	}
-	pr_cont(")\n");
+
+	supported[0] = 0;
+	for (i = 0; i < ACPI_S_STATE_COUNT; i++) {
+		if (sleep_states[i])
+			pos += sprintf(pos, " S%d", i);
+	}
+	pr_info(PREFIX "(supports%s)\n", supported);
+
 	/*
 	 * Register the tts_notifier to reboot notifier list so that the _TTS
 	 * object can also be evaluated when the system enters S5.
diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 0ea1018280b..beea3115577 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -1144,13 +1144,8 @@ static int ata_acpi_find_device(struct device *dev, acpi_handle *handle)
 		return -ENODEV;
 }
 
-static int ata_acpi_find_dummy(struct device *dev, acpi_handle *handle)
-{
-	return -ENODEV;
-}
-
 static struct acpi_bus_type ata_acpi_bus = {
-	.find_bridge = ata_acpi_find_dummy,
+	.name = "ATA",
 	.find_device = ata_acpi_find_device,
 };
 
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 2b7f77d3fcb..15beb500a4e 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -99,7 +99,6 @@ void device_pm_add(struct device *dev)
 		dev_warn(dev, "parent %s should not be sleeping\n",
 			dev_name(dev->parent));
 	list_add_tail(&dev->power.entry, &dpm_list);
-	dev_pm_qos_constraints_init(dev);
 	mutex_unlock(&dpm_list_mtx);
 }
 
@@ -113,7 +112,6 @@ void device_pm_remove(struct device *dev)
 		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 	complete_all(&dev->power.completion);
 	mutex_lock(&dpm_list_mtx);
-	dev_pm_qos_constraints_destroy(dev);
 	list_del_init(&dev->power.entry);
 	mutex_unlock(&dpm_list_mtx);
 	device_wakeup_disable(dev);
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index b16686a0a5a..cfc3226ec49 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -4,7 +4,7 @@ static inline void device_pm_init_common(struct device *dev)
 {
 	if (!dev->power.early_init) {
 		spin_lock_init(&dev->power.lock);
-		dev->power.power_state = PMSG_INVALID;
+		dev->power.qos = NULL;
 		dev->power.early_init = true;
 	}
 }
@@ -56,14 +56,10 @@ extern void device_pm_move_last(struct device *);
 
 static inline void device_pm_sleep_init(struct device *dev) {}
 
-static inline void device_pm_add(struct device *dev)
-{
-	dev_pm_qos_constraints_init(dev);
-}
+static inline void device_pm_add(struct device *dev) {}
 
 static inline void device_pm_remove(struct device *dev)
 {
-	dev_pm_qos_constraints_destroy(dev);
 	pm_runtime_remove(dev);
 }
 
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 3d4d1f8aac5..5f74587ef25 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -41,6 +41,7 @@
 #include <linux/mutex.h>
 #include <linux/export.h>
 #include <linux/pm_runtime.h>
+#include <linux/err.h>
 
 #include "power.h"
 
@@ -61,7 +62,7 @@ enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask)
 	struct pm_qos_flags *pqf;
 	s32 val;
 
-	if (!qos)
+	if (IS_ERR_OR_NULL(qos))
 		return PM_QOS_FLAGS_UNDEFINED;
 
 	pqf = &qos->flags;
@@ -101,7 +102,8 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_flags);
  */
 s32 __dev_pm_qos_read_value(struct device *dev)
 {
-	return dev->power.qos ? pm_qos_read_value(&dev->power.qos->latency) : 0;
+	return IS_ERR_OR_NULL(dev->power.qos) ?
+		0 : pm_qos_read_value(&dev->power.qos->latency);
 }
 
 /**
@@ -198,20 +200,8 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
 	return 0;
 }
 
-/**
- * dev_pm_qos_constraints_init - Initalize device's PM QoS constraints pointer.
- * @dev: target device
- *
- * Called from the device PM subsystem during device insertion under
- * device_pm_lock().
- */
-void dev_pm_qos_constraints_init(struct device *dev)
-{
-	mutex_lock(&dev_pm_qos_mtx);
-	dev->power.qos = NULL;
-	dev->power.power_state = PMSG_ON;
-	mutex_unlock(&dev_pm_qos_mtx);
-}
+static void __dev_pm_qos_hide_latency_limit(struct device *dev);
+static void __dev_pm_qos_hide_flags(struct device *dev);
 
 /**
  * dev_pm_qos_constraints_destroy
@@ -226,16 +216,15 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
 	struct pm_qos_constraints *c;
 	struct pm_qos_flags *f;
 
+	mutex_lock(&dev_pm_qos_mtx);
+
 	/*
 	 * If the device's PM QoS resume latency limit or PM QoS flags have been
 	 * exposed to user space, they have to be hidden at this point.
 	 */
-	dev_pm_qos_hide_latency_limit(dev);
-	dev_pm_qos_hide_flags(dev);
+	__dev_pm_qos_hide_latency_limit(dev);
+	__dev_pm_qos_hide_flags(dev);
 
-	mutex_lock(&dev_pm_qos_mtx);
-
-	dev->power.power_state = PMSG_INVALID;
 	qos = dev->power.qos;
 	if (!qos)
 		goto out;
@@ -257,7 +246,7 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
 	}
 
 	spin_lock_irq(&dev->power.lock);
-	dev->power.qos = NULL;
+	dev->power.qos = ERR_PTR(-ENODEV);
 	spin_unlock_irq(&dev->power.lock);
 
 	kfree(c->notifiers);
@@ -301,32 +290,19 @@ int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
 		 "%s() called for already added request\n", __func__))
 		return -EINVAL;
 
-	req->dev = dev;
-
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (!dev->power.qos) {
-		if (dev->power.power_state.event == PM_EVENT_INVALID) {
-			/* The device has been removed from the system. */
-			req->dev = NULL;
-			ret = -ENODEV;
-			goto out;
-		} else {
-			/*
-			 * Allocate the constraints data on the first call to
-			 * add_request, i.e. only if the data is not already
-			 * allocated and if the device has not been removed.
-			 */
-			ret = dev_pm_qos_constraints_allocate(dev);
-		}
-	}
+	if (IS_ERR(dev->power.qos))
+		ret = -ENODEV;
+	else if (!dev->power.qos)
+		ret = dev_pm_qos_constraints_allocate(dev);
 
 	if (!ret) {
+		req->dev = dev;
 		req->type = type;
 		ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
 	}
 
- out:
 	mutex_unlock(&dev_pm_qos_mtx);
 
 	return ret;
@@ -344,7 +320,14 @@ static int __dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 	s32 curr_value;
 	int ret = 0;
 
-	if (!req->dev->power.qos)
+	if (!req) /*guard against callers passing in null */
+		return -EINVAL;
+
+	if (WARN(!dev_pm_qos_request_active(req),
+		 "%s() called for unknown object\n", __func__))
+		return -EINVAL;
+
+	if (IS_ERR_OR_NULL(req->dev->power.qos))
 		return -ENODEV;
 
 	switch(req->type) {
@@ -386,6 +369,17 @@ int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
 {
 	int ret;
 
+	mutex_lock(&dev_pm_qos_mtx);
+	ret = __dev_pm_qos_update_request(req, new_value);
+	mutex_unlock(&dev_pm_qos_mtx);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
+
+static int __dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
+{
+	int ret;
+
 	if (!req) /*guard against callers passing in null */
 		return -EINVAL;
 
@@ -393,13 +387,13 @@ int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value)
 		 "%s() called for unknown object\n", __func__))
 		return -EINVAL;
 
-	mutex_lock(&dev_pm_qos_mtx);
-	ret = __dev_pm_qos_update_request(req, new_value);
-	mutex_unlock(&dev_pm_qos_mtx);
+	if (IS_ERR_OR_NULL(req->dev->power.qos))
+		return -ENODEV;
 
+	ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
+	memset(req, 0, sizeof(*req));
 	return ret;
 }
-EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
 
 /**
  * dev_pm_qos_remove_request - modifies an existing qos request
@@ -418,26 +412,10 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
  */
 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
 {
-	int ret = 0;
-
-	if (!req) /*guard against callers passing in null */
-		return -EINVAL;
-
-	if (WARN(!dev_pm_qos_request_active(req),
-		 "%s() called for unknown object\n", __func__))
-		return -EINVAL;
+	int ret;
 
 	mutex_lock(&dev_pm_qos_mtx);
-
-	if (req->dev->power.qos) {
-		ret = apply_constraint(req, PM_QOS_REMOVE_REQ,
-				       PM_QOS_DEFAULT_VALUE);
-		memset(req, 0, sizeof(*req));
-	} else {
-		/* Return if the device has been removed */
-		ret = -ENODEV;
-	}
-
+	ret = __dev_pm_qos_remove_request(req);
 	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }
@@ -462,9 +440,10 @@ int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	if (!dev->power.qos)
-		ret = dev->power.power_state.event != PM_EVENT_INVALID ?
-			dev_pm_qos_constraints_allocate(dev) : -ENODEV;
+	if (IS_ERR(dev->power.qos))
+		ret = -ENODEV;
+	else if (!dev->power.qos)
+		ret = dev_pm_qos_constraints_allocate(dev);
 
 	if (!ret)
 		ret = blocking_notifier_chain_register(
@@ -493,7 +472,7 @@ int dev_pm_qos_remove_notifier(struct device *dev,
 	mutex_lock(&dev_pm_qos_mtx);
 
 	/* Silently return if the constraints object is not present. */
-	if (dev->power.qos)
+	if (!IS_ERR_OR_NULL(dev->power.qos))
 		retval = blocking_notifier_chain_unregister(
 				dev->power.qos->latency.notifiers,
 				notifier);
@@ -563,16 +542,20 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);
 static void __dev_pm_qos_drop_user_request(struct device *dev,
 					   enum dev_pm_qos_req_type type)
 {
+	struct dev_pm_qos_request *req = NULL;
+
 	switch(type) {
 	case DEV_PM_QOS_LATENCY:
-		dev_pm_qos_remove_request(dev->power.qos->latency_req);
+		req = dev->power.qos->latency_req;
 		dev->power.qos->latency_req = NULL;
 		break;
 	case DEV_PM_QOS_FLAGS:
-		dev_pm_qos_remove_request(dev->power.qos->flags_req);
+		req = dev->power.qos->flags_req;
 		dev->power.qos->flags_req = NULL;
 		break;
 	}
+	__dev_pm_qos_remove_request(req);
+	kfree(req);
 }
 
 /**
@@ -588,36 +571,57 @@ int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
 	if (!device_is_registered(dev) || value < 0)
 		return -EINVAL;
 
-	if (dev->power.qos && dev->power.qos->latency_req)
-		return -EEXIST;
-
 	req = kzalloc(sizeof(*req), GFP_KERNEL);
 	if (!req)
 		return -ENOMEM;
 
 	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY, value);
-	if (ret < 0)
+	if (ret < 0) {
+		kfree(req);
 		return ret;
+	}
+
+	mutex_lock(&dev_pm_qos_mtx);
+
+	if (IS_ERR_OR_NULL(dev->power.qos))
+		ret = -ENODEV;
+	else if (dev->power.qos->latency_req)
+		ret = -EEXIST;
+
+	if (ret < 0) {
+		__dev_pm_qos_remove_request(req);
+		kfree(req);
+		goto out;
+	}
 
 	dev->power.qos->latency_req = req;
 	ret = pm_qos_sysfs_add_latency(dev);
 	if (ret)
 		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
 
+ out:
+	mutex_unlock(&dev_pm_qos_mtx);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit);
 
+static void __dev_pm_qos_hide_latency_limit(struct device *dev)
+{
+	if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->latency_req) {
+		pm_qos_sysfs_remove_latency(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
+	}
+}
+
 /**
  * dev_pm_qos_hide_latency_limit - Hide PM QoS latency limit from user space.
  * @dev: Device whose PM QoS latency limit is to be hidden from user space.
  */
 void dev_pm_qos_hide_latency_limit(struct device *dev)
 {
-	if (dev->power.qos && dev->power.qos->latency_req) {
-		pm_qos_sysfs_remove_latency(dev);
-		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
-	}
+	mutex_lock(&dev_pm_qos_mtx);
+	__dev_pm_qos_hide_latency_limit(dev);
+	mutex_unlock(&dev_pm_qos_mtx);
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit);
 
@@ -634,41 +638,61 @@ int dev_pm_qos_expose_flags(struct device *dev, s32 val)
 	if (!device_is_registered(dev))
 		return -EINVAL;
 
-	if (dev->power.qos && dev->power.qos->flags_req)
-		return -EEXIST;
-
 	req = kzalloc(sizeof(*req), GFP_KERNEL);
 	if (!req)
 		return -ENOMEM;
 
-	pm_runtime_get_sync(dev);
 	ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_FLAGS, val);
-	if (ret < 0)
-		goto fail;
+	if (ret < 0) {
+		kfree(req);
+		return ret;
+	}
+
+	pm_runtime_get_sync(dev);
+	mutex_lock(&dev_pm_qos_mtx);
+
+	if (IS_ERR_OR_NULL(dev->power.qos))
+		ret = -ENODEV;
+	else if (dev->power.qos->flags_req)
+		ret = -EEXIST;
+
+	if (ret < 0) {
+		__dev_pm_qos_remove_request(req);
+		kfree(req);
+		goto out;
+	}
 
 	dev->power.qos->flags_req = req;
 	ret = pm_qos_sysfs_add_flags(dev);
 	if (ret)
 		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
 
-fail:
+ out:
+	mutex_unlock(&dev_pm_qos_mtx);
 	pm_runtime_put(dev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags);
 
+static void __dev_pm_qos_hide_flags(struct device *dev)
+{
+	if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req) {
+		pm_qos_sysfs_remove_flags(dev);
+		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
+	}
+}
+
 /**
  * dev_pm_qos_hide_flags - Hide PM QoS flags of a device from user space.
  * @dev: Device whose PM QoS flags are to be hidden from user space.
  */
 void dev_pm_qos_hide_flags(struct device *dev)
 {
-	if (dev->power.qos && dev->power.qos->flags_req) {
-		pm_qos_sysfs_remove_flags(dev);
-		pm_runtime_get_sync(dev);
-		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
-		pm_runtime_put(dev);
-	}
+	pm_runtime_get_sync(dev);
+	mutex_lock(&dev_pm_qos_mtx);
+	__dev_pm_qos_hide_flags(dev);
+	mutex_unlock(&dev_pm_qos_mtx);
+	pm_runtime_put(dev);
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags);
 
@@ -683,12 +707,14 @@ int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set)
 	s32 value;
 	int ret;
 
-	if (!dev->power.qos || !dev->power.qos->flags_req)
-		return -EINVAL;
-
 	pm_runtime_get_sync(dev);
 	mutex_lock(&dev_pm_qos_mtx);
 
+	if (IS_ERR_OR_NULL(dev->power.qos) || !dev->power.qos->flags_req) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	value = dev_pm_qos_requested_flags(dev);
 	if (set)
 		value |= mask;
@@ -697,9 +723,12 @@ int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set)
 
 	ret = __dev_pm_qos_update_request(dev->power.qos->flags_req, value);
 
+ out:
 	mutex_unlock(&dev_pm_qos_mtx);
 	pm_runtime_put(dev);
-
 	return ret;
 }
+#else /* !CONFIG_PM_RUNTIME */
+static void __dev_pm_qos_hide_latency_limit(struct device *dev) {}
+static void __dev_pm_qos_hide_flags(struct device *dev) {}
 #endif /* CONFIG_PM_RUNTIME */
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 50d16e3cb0a..a53ebd26570 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -708,6 +708,7 @@ void rpm_sysfs_remove(struct device *dev)
 
 void dpm_sysfs_remove(struct device *dev)
 {
+	dev_pm_qos_constraints_destroy(dev);
 	rpm_sysfs_remove(dev);
 	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 	sysfs_remove_group(&dev->kobj, &pm_attr_group);
diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h
index d2ac9115060..46bde01eee6 100644
--- a/drivers/cpufreq/cpufreq_governor.h
+++ b/drivers/cpufreq/cpufreq_governor.h
@@ -64,7 +64,7 @@ static void *get_cpu_dbs_info_s(int cpu)				\
  * dbs: used as a shortform for demand based switching It helps to keep variable
  *	names smaller, simpler
  * cdbs: common dbs
- * on_*: On-demand governor
+ * od_*: On-demand governor
  * cs_*: Conservative governor
  */
 
diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c
index 66e3a71b81a..b61b5a3fad6 100644
--- a/drivers/cpufreq/highbank-cpufreq.c
+++ b/drivers/cpufreq/highbank-cpufreq.c
@@ -28,13 +28,7 @@
 
 static int hb_voltage_change(unsigned int freq)
 {
-	int i;
-	u32 msg[HB_CPUFREQ_IPC_LEN];
-
-	msg[0] = HB_CPUFREQ_CHANGE_NOTE;
-	msg[1] = freq / 1000000;
-	for (i = 2; i < HB_CPUFREQ_IPC_LEN; i++)
-		msg[i] = 0;
+	u32 msg[HB_CPUFREQ_IPC_LEN] = {HB_CPUFREQ_CHANGE_NOTE, freq / 1000000};
 
 	return pl320_ipc_transmit(msg);
 }
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 096fde0ebcb..f6dd1e76112 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -662,6 +662,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 
 	cpu = all_cpu_data[policy->cpu];
 
+	if (!policy->cpuinfo.max_freq)
+		return -ENODEV;
+
 	intel_pstate_get_min_max(cpu, &min, &max);
 
 	limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
@@ -747,37 +750,11 @@ static struct cpufreq_driver intel_pstate_driver = {
 	.owner		= THIS_MODULE,
 };
 
-static void intel_pstate_exit(void)
-{
-	int cpu;
-
-	sysfs_remove_group(intel_pstate_kobject,
-				&intel_pstate_attr_group);
-	debugfs_remove_recursive(debugfs_parent);
-
-	cpufreq_unregister_driver(&intel_pstate_driver);
-
-	if (!all_cpu_data)
-		return;
-
-	get_online_cpus();
-	for_each_online_cpu(cpu) {
-		if (all_cpu_data[cpu]) {
-			del_timer_sync(&all_cpu_data[cpu]->timer);
-			kfree(all_cpu_data[cpu]);
-		}
-	}
-
-	put_online_cpus();
-	vfree(all_cpu_data);
-}
-module_exit(intel_pstate_exit);
-
 static int __initdata no_load;
 
 static int __init intel_pstate_init(void)
 {
-	int rc = 0;
+	int cpu, rc = 0;
 	const struct x86_cpu_id *id;
 
 	if (no_load)
@@ -802,7 +779,16 @@ static int __init intel_pstate_init(void)
 	intel_pstate_sysfs_expose_params();
 	return rc;
 out:
-	intel_pstate_exit();
+	get_online_cpus();
+	for_each_online_cpu(cpu) {
+		if (all_cpu_data[cpu]) {
+			del_timer_sync(&all_cpu_data[cpu]->timer);
+			kfree(all_cpu_data[cpu]);
+		}
+	}
+
+	put_online_cpus();
+	vfree(all_cpu_data);
 	return -ENODEV;
 }
 device_initcall(intel_pstate_init);
diff --git a/drivers/mailbox/pl320-ipc.c b/drivers/mailbox/pl320-ipc.c
index c45b3aedafb..d873cbae2fb 100644
--- a/drivers/mailbox/pl320-ipc.c
+++ b/drivers/mailbox/pl320-ipc.c
@@ -138,8 +138,7 @@ int pl320_ipc_unregister_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(pl320_ipc_unregister_notifier);
 
-static int __init pl320_probe(struct amba_device *adev,
-				const struct amba_id *id)
+static int pl320_probe(struct amba_device *adev, const struct amba_id *id)
 {
 	int ret;
 
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 39c937f9b42..dee5dddaa29 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -331,8 +331,14 @@ static void pci_acpi_cleanup(struct device *dev)
 	}
 }
 
+static bool pci_acpi_bus_match(struct device *dev)
+{
+	return dev->bus == &pci_bus_type;
+}
+
 static struct acpi_bus_type acpi_pci_bus = {
-	.bus = &pci_bus_type,
+	.name = "PCI",
+	.match = pci_acpi_bus_match,
 	.find_device = acpi_pci_find_device,
 	.setup = pci_acpi_setup,
 	.cleanup = pci_acpi_cleanup,
diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
index 8813fc03aa0..55cd459a390 100644
--- a/drivers/pnp/pnpacpi/core.c
+++ b/drivers/pnp/pnpacpi/core.c
@@ -353,8 +353,14 @@ static int __init acpi_pnp_find_device(struct device *dev, acpi_handle * handle)
 /* complete initialization of a PNPACPI device includes having
  * pnpdev->dev.archdata.acpi_handle point to its ACPI sibling.
  */
+static bool acpi_pnp_bus_match(struct device *dev)
+{
+	return dev->bus == &pnp_bus_type;
+}
+
 static struct acpi_bus_type __initdata acpi_pnp_bus = {
-	.bus	     = &pnp_bus_type,
+	.name	     = "PNP",
+	.match	     = acpi_pnp_bus_match,
 	.find_device = acpi_pnp_find_device,
 };
 
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 765398c063c..c31187d7934 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -71,9 +71,14 @@ struct kmem_cache *scsi_sdb_cache;
 #ifdef CONFIG_ACPI
 #include <acpi/acpi_bus.h>
 
+static bool acpi_scsi_bus_match(struct device *dev)
+{
+	return dev->bus == &scsi_bus_type;
+}
+
 int scsi_register_acpi_bus_type(struct acpi_bus_type *bus)
 {
-        bus->bus = &scsi_bus_type;
+        bus->match = acpi_scsi_bus_match;
         return register_acpi_bus_type(bus);
 }
 EXPORT_SYMBOL_GPL(scsi_register_acpi_bus_type);
diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
index cef4252bb31..b6f4bad3f75 100644
--- a/drivers/usb/core/usb-acpi.c
+++ b/drivers/usb/core/usb-acpi.c
@@ -210,9 +210,14 @@ static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
 	return 0;
 }
 
+static bool usb_acpi_bus_match(struct device *dev)
+{
+	return is_usb_device(dev) || is_usb_port(dev);
+}
+
 static struct acpi_bus_type usb_acpi_bus = {
-	.bus = &usb_bus_type,
-	.find_bridge = usb_acpi_find_device,
+	.name = "USB",
+	.match = usb_acpi_bus_match,
 	.find_device = usb_acpi_find_device,
 };
 
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index e65278f560c..22ba56e834e 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -437,11 +437,9 @@ void acpi_remove_dir(struct acpi_device *);
  */
 struct acpi_bus_type {
 	struct list_head list;
-	struct bus_type *bus;
-	/* For general devices under the bus */
+	const char *name;
+	bool (*match)(struct device *dev);
 	int (*find_device) (struct device *, acpi_handle *);
-	/* For bridges, such as PCI root bridge, IDE controller */
-	int (*find_bridge) (struct device *, acpi_handle *);
 	void (*setup)(struct device *);
 	void (*cleanup)(struct device *);
 };