10 files changed, 284 insertions, 168 deletions

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 6c9387d646ec..5401814c874d 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -16,10 +16,11 @@
 #include <linux/interrupt.h>
 #include <linux/bitops.h>
 #include <linux/mutex.h>
-#include <linux/kthread.h>
+#include <linux/workqueue.h>
 #include <linux/highmem.h>
 #include <linux/firmware.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 
 #define to_dev(obj) container_of(obj, struct device, kobj)
 
@@ -81,6 +82,11 @@ enum {
 
 static int loading_timeout = 60;        /* In seconds */
 
+static inline long firmware_loading_timeout(void)
+{
+        return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
+}
+
 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
  * guarding for corner cases a global lock should be OK */
 static DEFINE_MUTEX(fw_lock);
@@ -440,13 +446,11 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
 {
         struct firmware_priv *fw_priv;
         struct device *f_dev;
-        int error;
 
         fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
         if (!fw_priv) {
                 dev_err(device, "%s: kmalloc failed\n", __func__);
-                error = -ENOMEM;
-                goto err_out;
+                return ERR_PTR(-ENOMEM);
         }
 
         fw_priv->fw = firmware;
@@ -463,98 +467,80 @@ fw_create_instance(struct firmware *firmware, const char *fw_name,
         f_dev->parent = device;
         f_dev->class = &firmware_class;
 
-        dev_set_uevent_suppress(f_dev, true);
-
-        /* Need to pin this module until class device is destroyed */
-        __module_get(THIS_MODULE);
-
-        error = device_add(f_dev);
-        if (error) {
-                dev_err(device, "%s: device_register failed\n", __func__);
-                goto err_put_dev;
-        }
-
-        error = device_create_bin_file(f_dev, &firmware_attr_data);
-        if (error) {
-                dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
-                goto err_del_dev;
-        }
-
-        error = device_create_file(f_dev, &dev_attr_loading);
-        if (error) {
-                dev_err(device, "%s: device_create_file failed\n", __func__);
-                goto err_del_bin_attr;
-        }
-
-        if (uevent)
-                dev_set_uevent_suppress(f_dev, false);
-
         return fw_priv;
-
-err_del_bin_attr:
-        device_remove_bin_file(f_dev, &firmware_attr_data);
-err_del_dev:
-        device_del(f_dev);
-err_put_dev:
-        put_device(f_dev);
-err_out:
-        return ERR_PTR(error);
 }
 
-static void fw_destroy_instance(struct firmware_priv *fw_priv)
-{
-        struct device *f_dev = &fw_priv->dev;
-
-        device_remove_file(f_dev, &dev_attr_loading);
-        device_remove_bin_file(f_dev, &firmware_attr_data);
-        device_unregister(f_dev);
-}
-
-static int _request_firmware(const struct firmware **firmware_p,
-                             const char *name, struct device *device,
-                             bool uevent, bool nowait)
+static struct firmware_priv *
+_request_firmware_prepare(const struct firmware **firmware_p, const char *name,
+                          struct device *device, bool uevent, bool nowait)
 {
-        struct firmware_priv *fw_priv;
         struct firmware *firmware;
-        int retval = 0;
+        struct firmware_priv *fw_priv;
 
         if (!firmware_p)
-                return -EINVAL;
+                return ERR_PTR(-EINVAL);
 
         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
         if (!firmware) {
                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
                         __func__);
-                return -ENOMEM;
+                return ERR_PTR(-ENOMEM);
         }
 
         if (fw_get_builtin_firmware(firmware, name)) {
                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
-                return 0;
+                return NULL;
+        }
+
+        fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
+        if (IS_ERR(fw_priv)) {
+                release_firmware(firmware);
+                *firmware_p = NULL;
         }
+        return fw_priv;
+}
 
-        read_lock_usermodehelper();
+static void _request_firmware_cleanup(const struct firmware **firmware_p)
+{
+        release_firmware(*firmware_p);
+        *firmware_p = NULL;
+}
 
-        if (WARN_ON(usermodehelper_is_disabled())) {
-                dev_err(device, "firmware: %s will not be loaded\n", name);
-                retval = -EBUSY;
-                goto out;
+static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
+                                  long timeout)
+{
+        int retval = 0;
+        struct device *f_dev = &fw_priv->dev;
+
+        dev_set_uevent_suppress(f_dev, true);
+
+        /* Need to pin this module until class device is destroyed */
+        __module_get(THIS_MODULE);
+
+        retval = device_add(f_dev);
+        if (retval) {
+                dev_err(f_dev, "%s: device_register failed\n", __func__);
+                goto err_put_dev;
         }
 
-        if (uevent)
-                dev_dbg(device, "firmware: requesting %s\n", name);
+        retval = device_create_bin_file(f_dev, &firmware_attr_data);
+        if (retval) {
+                dev_err(f_dev, "%s: sysfs_create_bin_file failed\n", __func__);
+                goto err_del_dev;
+        }
 
-        fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
-        if (IS_ERR(fw_priv)) {
-                retval = PTR_ERR(fw_priv);
-                goto out;
+        retval = device_create_file(f_dev, &dev_attr_loading);
+        if (retval) {
+                dev_err(f_dev, "%s: device_create_file failed\n", __func__);
+                goto err_del_bin_attr;
         }
 
         if (uevent) {
-                if (loading_timeout > 0)
+                dev_set_uevent_suppress(f_dev, false);
+                dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_id);
+                if (timeout != MAX_SCHEDULE_TIMEOUT)
                         mod_timer(&fw_priv->timeout,
-                                  round_jiffies_up(jiffies +
-                                                   loading_timeout * HZ));
+                                  round_jiffies_up(jiffies + timeout));
 
                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
         }
@@ -570,16 +556,13 @@ static int _request_firmware(const struct firmware **firmware_p,
         fw_priv->fw = NULL;
         mutex_unlock(&fw_lock);
 
-        fw_destroy_instance(fw_priv);
-
-out:
-        read_unlock_usermodehelper();
-
-        if (retval) {
-                release_firmware(firmware);
-                *firmware_p = NULL;
-        }
-
+        device_remove_file(f_dev, &dev_attr_loading);
+err_del_bin_attr:
+        device_remove_bin_file(f_dev, &firmware_attr_data);
+err_del_dev:
+        device_del(f_dev);
+err_put_dev:
+        put_device(f_dev);
         return retval;
 }
 
@@ -602,7 +585,26 @@ int
 request_firmware(const struct firmware **firmware_p, const char *name,
                  struct device *device)
 {
-        return _request_firmware(firmware_p, name, device, true, false);
+        struct firmware_priv *fw_priv;
+        int ret;
+
+        fw_priv = _request_firmware_prepare(firmware_p, name, device, true,
+                                            false);
+        if (IS_ERR_OR_NULL(fw_priv))
+                return PTR_RET(fw_priv);
+
+        ret = usermodehelper_read_trylock();
+        if (WARN_ON(ret)) {
+                dev_err(device, "firmware: %s will not be loaded\n", name);
+        } else {
+                ret = _request_firmware_load(fw_priv, true,
+                                        firmware_loading_timeout());
+                usermodehelper_read_unlock();
+        }
+        if (ret)
+                _request_firmware_cleanup(firmware_p);
+
+        return ret;
 }
 
 /**
@@ -629,25 +631,39 @@ struct firmware_work {
         bool uevent;
 };
 
-static int request_firmware_work_func(void *arg)
+static void request_firmware_work_func(struct work_struct *work)
 {
-        struct firmware_work *fw_work = arg;
+        struct firmware_work *fw_work;
         const struct firmware *fw;
+        struct firmware_priv *fw_priv;
+        long timeout;
         int ret;
 
-        if (!arg) {
-                WARN_ON(1);
-                return 0;
+        fw_work = container_of(work, struct firmware_work, work);
+        fw_priv = _request_firmware_prepare(&fw, fw_work->name, fw_work->device,
+                        fw_work->uevent, true);
+        if (IS_ERR_OR_NULL(fw_priv)) {
+                ret = PTR_RET(fw_priv);
+                goto out;
+        }
+
+        timeout = usermodehelper_read_lock_wait(firmware_loading_timeout());
+        if (timeout) {
+                ret = _request_firmware_load(fw_priv, fw_work->uevent, timeout);
+                usermodehelper_read_unlock();
+        } else {
+                dev_dbg(fw_work->device, "firmware: %s loading timed out\n",
+                        fw_work->name);
+                ret = -EAGAIN;
         }
+        if (ret)
+                _request_firmware_cleanup(&fw);
 
-        ret = _request_firmware(&fw, fw_work->name, fw_work->device,
-                                fw_work->uevent, true);
+ out:
         fw_work->cont(fw, fw_work->context);
 
         module_put(fw_work->module);
         kfree(fw_work);
-
-        return ret;
 }
 
 /**
@@ -673,7 +689,6 @@ request_firmware_nowait(
         const char *name, struct device *device, gfp_t gfp, void *context,
         void (*cont)(const struct firmware *fw, void *context))
 {
-        struct task_struct *task;
         struct firmware_work *fw_work;
 
         fw_work = kzalloc(sizeof (struct firmware_work), gfp);
@@ -692,15 +707,8 @@ request_firmware_nowait(
                 return -EFAULT;
         }
 
-        task = kthread_run(request_firmware_work_func, fw_work,
-                            "firmware/%s", name);
-        if (IS_ERR(task)) {
-                fw_work->cont(NULL, fw_work->context);
-                module_put(fw_work->module);
-                kfree(fw_work);
-                return PTR_ERR(task);
-        }
-
+        INIT_WORK(&fw_work->work, request_firmware_work_func);
+        schedule_work(&fw_work->work);
         return 0;
 }
 
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 541f821d4ea6..bd0f3949bcf9 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -532,6 +532,8 @@ static int rpm_suspend(struct device *dev, int rpmflags)
         dev->power.suspend_time = ktime_set(0, 0);
         dev->power.max_time_suspended_ns = -1;
         dev->power.deferred_resume = false;
+        wake_up_all(&dev->power.wait_queue);
+
         if (retval == -EAGAIN || retval == -EBUSY) {
                 dev->power.runtime_error = 0;
 
@@ -547,7 +549,6 @@ static int rpm_suspend(struct device *dev, int rpmflags)
         } else {
                 pm_runtime_cancel_pending(dev);
         }
-        wake_up_all(&dev->power.wait_queue);
         goto out;
 }
 
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 9efeae679106..dd99c329e161 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -110,12 +110,29 @@ call_usermodehelper(char *path, char **argv, char **envp, int wait)
 
 extern struct ctl_table usermodehelper_table[];
 
+enum umh_disable_depth {
+        UMH_ENABLED = 0,
+        UMH_FREEZING,
+        UMH_DISABLED,
+};
+
 extern void usermodehelper_init(void);
 
-extern int usermodehelper_disable(void);
-extern void usermodehelper_enable(void);
-extern bool usermodehelper_is_disabled(void);
-extern void read_lock_usermodehelper(void);
-extern void read_unlock_usermodehelper(void);
+extern int __usermodehelper_disable(enum umh_disable_depth depth);
+extern void __usermodehelper_set_disable_depth(enum umh_disable_depth depth);
+
+static inline int usermodehelper_disable(void)
+{
+        return __usermodehelper_disable(UMH_DISABLED);
+}
+
+static inline void usermodehelper_enable(void)
+{
+        __usermodehelper_set_disable_depth(UMH_ENABLED);
+}
+
+extern int usermodehelper_read_trylock(void);
+extern long usermodehelper_read_lock_wait(long timeout);
+extern void usermodehelper_read_unlock(void);
 
 #endif /* __LINUX_KMOD_H__ */
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 2e9191a712f3..233149cb19f4 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -8,6 +8,7 @@
 #include <linux/notifier.h>
 #include <linux/miscdevice.h>
 #include <linux/device.h>
+#include <linux/workqueue.h>
 
 enum {
         PM_QOS_RESERVED = 0,
@@ -29,6 +30,7 @@ enum {
 struct pm_qos_request {
         struct plist_node node;
         int pm_qos_class;
+        struct delayed_work work; /* for pm_qos_update_request_timeout */
 };
 
 struct dev_pm_qos_request {
@@ -73,6 +75,8 @@ void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
                         s32 value);
 void pm_qos_update_request(struct pm_qos_request *req,
                            s32 new_value);
+void pm_qos_update_request_timeout(struct pm_qos_request *req,
+                                   s32 new_value, unsigned long timeout_us);
 void pm_qos_remove_request(struct pm_qos_request *req);
 
 int pm_qos_request(int pm_qos_class);
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 957a7aab8ebc..05698a7415fe 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -322,7 +322,7 @@ static void __call_usermodehelper(struct work_struct *work)
  * land has been frozen during a system-wide hibernation or suspend operation).
  * Should always be manipulated under umhelper_sem acquired for write.
  */
-static int usermodehelper_disabled = 1;
+static enum umh_disable_depth usermodehelper_disabled = UMH_DISABLED;
 
 /* Number of helpers running */
 static atomic_t running_helpers = ATOMIC_INIT(0);
@@ -334,32 +334,110 @@ static atomic_t running_helpers = ATOMIC_INIT(0);
 static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
 
 /*
+ * Used by usermodehelper_read_lock_wait() to wait for usermodehelper_disabled
+ * to become 'false'.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(usermodehelper_disabled_waitq);
+
+/*
  * Time to wait for running_helpers to become zero before the setting of
  * usermodehelper_disabled in usermodehelper_disable() fails
  */
 #define RUNNING_HELPERS_TIMEOUT (5 * HZ)
 
-void read_lock_usermodehelper(void)
+int usermodehelper_read_trylock(void)
 {
+        DEFINE_WAIT(wait);
+        int ret = 0;
+
         down_read(&umhelper_sem);
+        for (;;) {
+                prepare_to_wait(&usermodehelper_disabled_waitq, &wait,
+                                TASK_INTERRUPTIBLE);
+                if (!usermodehelper_disabled)
+                        break;
+
+                if (usermodehelper_disabled == UMH_DISABLED)
+                        ret = -EAGAIN;
+
+                up_read(&umhelper_sem);
+
+                if (ret)
+                        break;
+
+                schedule();
+                try_to_freeze();
+
+                down_read(&umhelper_sem);
+        }
+        finish_wait(&usermodehelper_disabled_waitq, &wait);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(usermodehelper_read_trylock);
+
+long usermodehelper_read_lock_wait(long timeout)
+{
+        DEFINE_WAIT(wait);
+
+        if (timeout < 0)
+                return -EINVAL;
+
+        down_read(&umhelper_sem);
+        for (;;) {
+                prepare_to_wait(&usermodehelper_disabled_waitq, &wait,
+                                TASK_UNINTERRUPTIBLE);
+                if (!usermodehelper_disabled)
+                        break;
+
+                up_read(&umhelper_sem);
+
+                timeout = schedule_timeout(timeout);
+                if (!timeout)
+                        break;
+
+                down_read(&umhelper_sem);
+        }
+        finish_wait(&usermodehelper_disabled_waitq, &wait);
+        return timeout;
 }
-EXPORT_SYMBOL_GPL(read_lock_usermodehelper);
+EXPORT_SYMBOL_GPL(usermodehelper_read_lock_wait);
 
-void read_unlock_usermodehelper(void)
+void usermodehelper_read_unlock(void)
 {
         up_read(&umhelper_sem);
 }
-EXPORT_SYMBOL_GPL(read_unlock_usermodehelper);
+EXPORT_SYMBOL_GPL(usermodehelper_read_unlock);
 
 /**
- * usermodehelper_disable - prevent new helpers from being started
+ * __usermodehelper_set_disable_depth - Modify usermodehelper_disabled.
+ * depth: New value to assign to usermodehelper_disabled.
+ *
+ * Change the value of usermodehelper_disabled (under umhelper_sem locked for
+ * writing) and wakeup tasks waiting for it to change.
  */
-int usermodehelper_disable(void)
+void __usermodehelper_set_disable_depth(enum umh_disable_depth depth)
+{
+        down_write(&umhelper_sem);
+        usermodehelper_disabled = depth;
+        wake_up(&usermodehelper_disabled_waitq);
+        up_write(&umhelper_sem);
+}
+
+/**
+ * __usermodehelper_disable - Prevent new helpers from being started.
+ * @depth: New value to assign to usermodehelper_disabled.
+ *
+ * Set usermodehelper_disabled to @depth and wait for running helpers to exit.
+ */
+int __usermodehelper_disable(enum umh_disable_depth depth)
 {
         long retval;
 
+        if (!depth)
+                return -EINVAL;
+
         down_write(&umhelper_sem);
-        usermodehelper_disabled = 1;
+        usermodehelper_disabled = depth;
         up_write(&umhelper_sem);
 
         /*
@@ -374,31 +452,10 @@ int usermodehelper_disable(void)
         if (retval)
                 return 0;
 
-        down_write(&umhelper_sem);
-        usermodehelper_disabled = 0;
-        up_write(&umhelper_sem);
+        __usermodehelper_set_disable_depth(UMH_ENABLED);
         return -EAGAIN;
 }
 
-/**
- * usermodehelper_enable - allow new helpers to be started again
- */
-void usermodehelper_enable(void)
-{
-        down_write(&umhelper_sem);
-        usermodehelper_disabled = 0;
-        up_write(&umhelper_sem);
-}
-
-/**
- * usermodehelper_is_disabled - check if new helpers are allowed to be started
- */
-bool usermodehelper_is_disabled(void)
-{
-        return usermodehelper_disabled;
-}
-EXPORT_SYMBOL_GPL(usermodehelper_is_disabled);
-
 static void helper_lock(void)
 {
         atomic_inc(&running_helpers);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 0a186cfde788..e09dfbfeecee 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -16,7 +16,6 @@
 #include <linux/string.h>
 #include <linux/device.h>
 #include <linux/async.h>
-#include <linux/kmod.h>
 #include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/mount.h>
@@ -611,14 +610,10 @@ int hibernate(void)
         if (error)
                 goto Exit;
 
-        error = usermodehelper_disable();
-        if (error)
-                goto Exit;
-
         /* Allocate memory management structures */
         error = create_basic_memory_bitmaps();
         if (error)
-                goto Enable_umh;
+                goto Exit;
 
         printk(KERN_INFO "PM: Syncing filesystems ... ");
         sys_sync();
@@ -661,8 +656,6 @@ int hibernate(void)
 
  Free_bitmaps:
         free_basic_memory_bitmaps();
- Enable_umh:
-        usermodehelper_enable();
  Exit:
         pm_notifier_call_chain(PM_POST_HIBERNATION);
         pm_restore_console();
@@ -777,15 +770,9 @@ static int software_resume(void)
         if (error)
                 goto close_finish;
 
-        error = usermodehelper_disable();
-        if (error)
-                goto close_finish;
-
         error = create_basic_memory_bitmaps();
-        if (error) {
-                usermodehelper_enable();
+        if (error)
                 goto close_finish;
-        }
 
         pr_debug("PM: Preparing processes for restore.\n");
         error = freeze_processes();
@@ -806,7 +793,6 @@ static int software_resume(void)
         thaw_processes();
  Done:
         free_basic_memory_bitmaps();
-        usermodehelper_enable();
  Finish:
         pm_notifier_call_chain(PM_POST_RESTORE);
         pm_restore_console();
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 0d2aeb226108..19db29f67558 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -16,6 +16,7 @@
 #include <linux/freezer.h>
 #include <linux/delay.h>
 #include <linux/workqueue.h>
+#include <linux/kmod.h>
 
 /* 
  * Timeout for stopping processes
@@ -122,6 +123,10 @@ int freeze_processes(void)
 {
         int error;
 
+        error = __usermodehelper_disable(UMH_FREEZING);
+        if (error)
+                return error;
+
         if (!pm_freezing)
                 atomic_inc(&system_freezing_cnt);
 
@@ -130,6 +135,7 @@ int freeze_processes(void)
         error = try_to_freeze_tasks(true);
         if (!error) {
                 printk("done.");
+                __usermodehelper_set_disable_depth(UMH_DISABLED);
                 oom_killer_disable();
         }
         printk("\n");
@@ -187,6 +193,8 @@ void thaw_processes(void)
         } while_each_thread(g, p);
         read_unlock(&tasklist_lock);
 
+        usermodehelper_enable();
+
         schedule();
         printk("done.\n");
 }
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index d6d6dbd1ecc0..6a031e684026 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -230,6 +230,21 @@ int pm_qos_request_active(struct pm_qos_request *req)
 EXPORT_SYMBOL_GPL(pm_qos_request_active);
 
 /**
+ * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
+ * @work: work struct for the delayed work (timeout)
+ *
+ * This cancels the timeout request by falling back to the default at timeout.
+ */
+static void pm_qos_work_fn(struct work_struct *work)
+{
+        struct pm_qos_request *req = container_of(to_delayed_work(work),
+                                                  struct pm_qos_request,
+                                                  work);
+
+        pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
+}
+
+/**
  * pm_qos_add_request - inserts new qos request into the list
  * @req: pointer to a preallocated handle
  * @pm_qos_class: identifies which list of qos request to use
@@ -253,6 +268,7 @@ void pm_qos_add_request(struct pm_qos_request *req,
                 return;
         }
         req->pm_qos_class = pm_qos_class;
+        INIT_DELAYED_WORK(&req->work, pm_qos_work_fn);
         pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints,
                              &req->node, PM_QOS_ADD_REQ, value);
 }
@@ -279,6 +295,9 @@ void pm_qos_update_request(struct pm_qos_request *req,
                 return;
         }
 
+        if (delayed_work_pending(&req->work))
+                cancel_delayed_work_sync(&req->work);
+
         if (new_value != req->node.prio)
                 pm_qos_update_target(
                         pm_qos_array[req->pm_qos_class]->constraints,
@@ -287,6 +306,34 @@ void pm_qos_update_request(struct pm_qos_request *req,
 EXPORT_SYMBOL_GPL(pm_qos_update_request);
 
 /**
+ * pm_qos_update_request_timeout - modifies an existing qos request temporarily.
+ * @req : handle to list element holding a pm_qos request to use
+ * @new_value: defines the temporal qos request
+ * @timeout_us: the effective duration of this qos request in usecs.
+ *
+ * After timeout_us, this qos request is cancelled automatically.
+ */
+void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
+                                   unsigned long timeout_us)
+{
+        if (!req)
+                return;
+        if (WARN(!pm_qos_request_active(req),
+                 "%s called for unknown object.", __func__))
+                return;
+
+        if (delayed_work_pending(&req->work))
+                cancel_delayed_work_sync(&req->work);
+
+        if (new_value != req->node.prio)
+                pm_qos_update_target(
+                        pm_qos_array[req->pm_qos_class]->constraints,
+                        &req->node, PM_QOS_UPDATE_REQ, new_value);
+
+        schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us));
+}
+
+/**
  * pm_qos_remove_request - modifies an existing qos request
  * @req: handle to request list element
  *
@@ -305,6 +352,9 @@ void pm_qos_remove_request(struct pm_qos_request *req)
                 return;
         }
 
+        if (delayed_work_pending(&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,
                              PM_QOS_DEFAULT_VALUE);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 88e5c967370d..396d262b8fd0 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -12,7 +12,6 @@
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/init.h>
-#include <linux/kmod.h>
 #include <linux/console.h>
 #include <linux/cpu.h>
 #include <linux/syscalls.h>
@@ -102,17 +101,12 @@ static int suspend_prepare(void)
         if (error)
                 goto Finish;
 
-        error = usermodehelper_disable();
-        if (error)
-                goto Finish;
-
         error = suspend_freeze_processes();
         if (!error)
                 return 0;
 
         suspend_stats.failed_freeze++;
         dpm_save_failed_step(SUSPEND_FREEZE);
-        usermodehelper_enable();
  Finish:
         pm_notifier_call_chain(PM_POST_SUSPEND);
         pm_restore_console();
@@ -259,7 +253,6 @@ int suspend_devices_and_enter(suspend_state_t state)
 static void suspend_finish(void)
 {
         suspend_thaw_processes();
-        usermodehelper_enable();
         pm_notifier_call_chain(PM_POST_SUSPEND);
         pm_restore_console();
 }
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 33c4329205af..91b0fd021a95 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -12,7 +12,6 @@
 #include <linux/suspend.h>
 #include <linux/syscalls.h>
 #include <linux/reboot.h>
-#include <linux/kmod.h>
 #include <linux/string.h>
 #include <linux/device.h>
 #include <linux/miscdevice.h>
@@ -222,14 +221,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                 sys_sync();
                 printk("done.\n");
 
-                error = usermodehelper_disable();
-                if (error)
-                        break;
-
                 error = freeze_processes();
-                if (error)
-                        usermodehelper_enable();
-                else
+                if (!error)
                         data->frozen = 1;
                 break;
 
@@ -238,7 +231,6 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                         break;
                 pm_restore_gfp_mask();
                 thaw_processes();
-                usermodehelper_enable();
                 data->frozen = 0;
                 break;