Merge tag 'pm+acpi-3.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:

 - Revert of a recent cpuidle change that caused Nehalem machines to
   hang on boot from Alex Shi.

 - USB power management fix addressing a crash in the port device
   object's release routine from Rafael J Wysocki.

 - Device PM QoS fix for a potential deadlock related to sysfs interface
   from Rafael J Wysocki.

 - Fix for a cpufreq crash when the /cpus Device Tree node is missing
   from Paolo Pisati.

 - Fix for a build issue on ia64 related to the Boot Graphics Resource
   Table (BGRT) from Tony Luck.

 - Two fixes for ACPI handles being set incorrectly for device objects
   that don't correspond to any ACPI namespace nodes in the I2C and SPI
   subsystems from Rafael J Wysocki.

 - Fix for compiler warnings related to CONFIG_PM_DEVFREQ being unset
   from Rajagopal Venkat.

 - Fix for a symbol definition typo in cpufreq_governor.h from Borislav
   Petkov.

* tag 'pm+acpi-3.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / BGRT: Don't let users configure BGRT on non X86 systems
  cpuidle / ACPI: recover percpu ACPI processor cstate
  ACPI / I2C: Use parent's ACPI_HANDLE() in acpi_i2c_register_devices()
  cpufreq: Correct header guards typo
  ACPI / SPI: Use parent's ACPI_HANDLE() in acpi_register_spi_devices()
  cpufreq: check OF node /cpus presence before dereferencing it
  PM / devfreq: Fix compiler warnings for CONFIG_PM_DEVFREQ unset
  PM / QoS: Avoid possible deadlock related to sysfs access
  USB / PM: Don't try to hide PM QoS flags from usb_port_device_release()

1 files changed, 47 insertions, 13 deletions

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 5f74587ef25..71671c42ef4 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -46,6 +46,7 @@
 #include "power.h"
 
 static DEFINE_MUTEX(dev_pm_qos_mtx);
+static DEFINE_MUTEX(dev_pm_qos_sysfs_mtx);
 
 static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
 
@@ -216,12 +217,17 @@ 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);
+	mutex_lock(&dev_pm_qos_sysfs_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.
 	 */
+	pm_qos_sysfs_remove_latency(dev);
+	pm_qos_sysfs_remove_flags(dev);
+
+	mutex_lock(&dev_pm_qos_mtx);
+
 	__dev_pm_qos_hide_latency_limit(dev);
 	__dev_pm_qos_hide_flags(dev);
 
@@ -254,6 +260,8 @@ void dev_pm_qos_constraints_destroy(struct device *dev)
 
  out:
 	mutex_unlock(&dev_pm_qos_mtx);
+
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
 }
 
 /**
@@ -558,6 +566,14 @@ static void __dev_pm_qos_drop_user_request(struct device *dev,
 	kfree(req);
 }
 
+static void dev_pm_qos_drop_user_request(struct device *dev,
+					 enum dev_pm_qos_req_type type)
+{
+	mutex_lock(&dev_pm_qos_mtx);
+	__dev_pm_qos_drop_user_request(dev, type);
+	mutex_unlock(&dev_pm_qos_mtx);
+}
+
 /**
  * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space.
  * @dev: Device whose PM QoS latency limit is to be exposed to user space.
@@ -581,6 +597,8 @@ int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
 		return ret;
 	}
 
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+
 	mutex_lock(&dev_pm_qos_mtx);
 
 	if (IS_ERR_OR_NULL(dev->power.qos))
@@ -591,26 +609,27 @@ int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
 	if (ret < 0) {
 		__dev_pm_qos_remove_request(req);
 		kfree(req);
+		mutex_unlock(&dev_pm_qos_mtx);
 		goto out;
 	}
-
 	dev->power.qos->latency_req = req;
+
+	mutex_unlock(&dev_pm_qos_mtx);
+
 	ret = pm_qos_sysfs_add_latency(dev);
 	if (ret)
-		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
+		dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
 
  out:
-	mutex_unlock(&dev_pm_qos_mtx);
+	mutex_unlock(&dev_pm_qos_sysfs_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);
+	if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->latency_req)
 		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY);
-	}
 }
 
 /**
@@ -619,9 +638,15 @@ static void __dev_pm_qos_hide_latency_limit(struct device *dev)
  */
 void dev_pm_qos_hide_latency_limit(struct device *dev)
 {
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+
+	pm_qos_sysfs_remove_latency(dev);
+
 	mutex_lock(&dev_pm_qos_mtx);
 	__dev_pm_qos_hide_latency_limit(dev);
 	mutex_unlock(&dev_pm_qos_mtx);
+
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit);
 
@@ -649,6 +674,8 @@ int dev_pm_qos_expose_flags(struct device *dev, s32 val)
 	}
 
 	pm_runtime_get_sync(dev);
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+
 	mutex_lock(&dev_pm_qos_mtx);
 
 	if (IS_ERR_OR_NULL(dev->power.qos))
@@ -659,16 +686,19 @@ int dev_pm_qos_expose_flags(struct device *dev, s32 val)
 	if (ret < 0) {
 		__dev_pm_qos_remove_request(req);
 		kfree(req);
+		mutex_unlock(&dev_pm_qos_mtx);
 		goto out;
 	}
-
 	dev->power.qos->flags_req = req;
+
+	mutex_unlock(&dev_pm_qos_mtx);
+
 	ret = pm_qos_sysfs_add_flags(dev);
 	if (ret)
-		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
+		dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
 
  out:
-	mutex_unlock(&dev_pm_qos_mtx);
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
 	pm_runtime_put(dev);
 	return ret;
 }
@@ -676,10 +706,8 @@ 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);
+	if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req)
 		__dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS);
-	}
 }
 
 /**
@@ -689,9 +717,15 @@ static void __dev_pm_qos_hide_flags(struct device *dev)
 void dev_pm_qos_hide_flags(struct device *dev)
 {
 	pm_runtime_get_sync(dev);
+	mutex_lock(&dev_pm_qos_sysfs_mtx);
+
+	pm_qos_sysfs_remove_flags(dev);
+
 	mutex_lock(&dev_pm_qos_mtx);
 	__dev_pm_qos_hide_flags(dev);
 	mutex_unlock(&dev_pm_qos_mtx);
+
+	mutex_unlock(&dev_pm_qos_sysfs_mtx);
 	pm_runtime_put(dev);
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags);