1 files changed, 503 insertions, 441 deletions

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index b78c401ffa73..1dd8676d7f55 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -2,17 +2,55 @@
  * drivers/base/power/runtime.c - Helper functions for device run-time PM
  *
  * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu>
  *
  * This file is released under the GPLv2.
  */
 
 #include <linux/sched.h>
 #include <linux/pm_runtime.h>
-#include <linux/jiffies.h>
+#include "power.h"
 
-static int __pm_runtime_resume(struct device *dev, bool from_wq);
-static int __pm_request_idle(struct device *dev);
-static int __pm_request_resume(struct device *dev);
+static int rpm_resume(struct device *dev, int rpmflags);
+static int rpm_suspend(struct device *dev, int rpmflags);
+
+/**
+ * update_pm_runtime_accounting - Update the time accounting of power states
+ * @dev: Device to update the accounting for
+ *
+ * In order to be able to have time accounting of the various power states
+ * (as used by programs such as PowerTOP to show the effectiveness of runtime
+ * PM), we need to track the time spent in each state.
+ * update_pm_runtime_accounting must be called each time before the
+ * runtime_status field is updated, to account the time in the old state
+ * correctly.
+ */
+void update_pm_runtime_accounting(struct device *dev)
+{
+        unsigned long now = jiffies;
+        int delta;
+
+        delta = now - dev->power.accounting_timestamp;
+
+        if (delta < 0)
+                delta = 0;
+
+        dev->power.accounting_timestamp = now;
+
+        if (dev->power.disable_depth > 0)
+                return;
+
+        if (dev->power.runtime_status == RPM_SUSPENDED)
+                dev->power.suspended_jiffies += delta;
+        else
+                dev->power.active_jiffies += delta;
+}
+
+static void __update_runtime_status(struct device *dev, enum rpm_status status)
+{
+        update_pm_runtime_accounting(dev);
+        dev->power.runtime_status = status;
+}
 
 /**
  * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
@@ -40,62 +78,154 @@ static void pm_runtime_cancel_pending(struct device *dev)
         dev->power.request = RPM_REQ_NONE;
 }
 
-/**
- * __pm_runtime_idle - Notify device bus type if the device can be suspended.
- * @dev: Device to notify the bus type about.
+/*
+ * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time.
+ * @dev: Device to handle.
  *
- * This function must be called under dev->power.lock with interrupts disabled.
+ * Compute the autosuspend-delay expiration time based on the device's
+ * power.last_busy time.  If the delay has already expired or is disabled
+ * (negative) or the power.use_autosuspend flag isn't set, return 0.
+ * Otherwise return the expiration time in jiffies (adjusted to be nonzero).
+ *
+ * This function may be called either with or without dev->power.lock held.
+ * Either way it can be racy, since power.last_busy may be updated at any time.
  */
-static int __pm_runtime_idle(struct device *dev)
-        __releases(&dev->power.lock) __acquires(&dev->power.lock)
+unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
+{
+        int autosuspend_delay;
+        long elapsed;
+        unsigned long last_busy;
+        unsigned long expires = 0;
+
+        if (!dev->power.use_autosuspend)
+                goto out;
+
+        autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
+        if (autosuspend_delay < 0)
+                goto out;
+
+        last_busy = ACCESS_ONCE(dev->power.last_busy);
+        elapsed = jiffies - last_busy;
+        if (elapsed < 0)
+                goto out;       /* jiffies has wrapped around. */
+
+        /*
+         * If the autosuspend_delay is >= 1 second, align the timer by rounding
+         * up to the nearest second.
+         */
+        expires = last_busy + msecs_to_jiffies(autosuspend_delay);
+        if (autosuspend_delay >= 1000)
+                expires = round_jiffies(expires);
+        expires += !expires;
+        if (elapsed >= expires - last_busy)
+                expires = 0;    /* Already expired. */
+
+ out:
+        return expires;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
+
+/**
+ * rpm_check_suspend_allowed - Test whether a device may be suspended.
+ * @dev: Device to test.
+ */
+static int rpm_check_suspend_allowed(struct device *dev)
 {
         int retval = 0;
 
         if (dev->power.runtime_error)
                 retval = -EINVAL;
-        else if (dev->power.idle_notification)
-                retval = -EINPROGRESS;
         else if (atomic_read(&dev->power.usage_count) > 0
-            || dev->power.disable_depth > 0
-            || dev->power.runtime_status != RPM_ACTIVE)
+            || dev->power.disable_depth > 0)
                 retval = -EAGAIN;
         else if (!pm_children_suspended(dev))
                 retval = -EBUSY;
+
+        /* Pending resume requests take precedence over suspends. */
+        else if ((dev->power.deferred_resume
+                        && dev->power.status == RPM_SUSPENDING)
+            || (dev->power.request_pending
+                        && dev->power.request == RPM_REQ_RESUME))
+                retval = -EAGAIN;
+        else if (dev->power.runtime_status == RPM_SUSPENDED)
+                retval = 1;
+
+        return retval;
+}
+
+/**
+ * rpm_idle - Notify device bus type if the device can be suspended.
+ * @dev: Device to notify the bus type about.
+ * @rpmflags: Flag bits.
+ *
+ * Check if the device's run-time PM status allows it to be suspended.  If
+ * another idle notification has been started earlier, return immediately.  If
+ * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise
+ * run the ->runtime_idle() callback directly.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static int rpm_idle(struct device *dev, int rpmflags)
+{
+        int (*callback)(struct device *);
+        int retval;
+
+        retval = rpm_check_suspend_allowed(dev);
+        if (retval < 0)
+                ;       /* Conditions are wrong. */
+
+        /* Idle notifications are allowed only in the RPM_ACTIVE state. */
+        else if (dev->power.runtime_status != RPM_ACTIVE)
+                retval = -EAGAIN;
+
+        /*
+         * Any pending request other than an idle notification takes
+         * precedence over us, except that the timer may be running.
+         */
+        else if (dev->power.request_pending &&
+            dev->power.request > RPM_REQ_IDLE)
+                retval = -EAGAIN;
+
+        /* Act as though RPM_NOWAIT is always set. */
+        else if (dev->power.idle_notification)
+                retval = -EINPROGRESS;
         if (retval)
                 goto out;
 
-        if (dev->power.request_pending) {
-                /*
-                 * If an idle notification request is pending, cancel it.  Any
-                 * other pending request takes precedence over us.
-                 */
-                if (dev->power.request == RPM_REQ_IDLE) {
-                        dev->power.request = RPM_REQ_NONE;
-                } else if (dev->power.request != RPM_REQ_NONE) {
-                        retval = -EAGAIN;
-                        goto out;
+        /* Pending requests need to be canceled. */
+        dev->power.request = RPM_REQ_NONE;
+
+        if (dev->power.no_callbacks) {
+                /* Assume ->runtime_idle() callback would have suspended. */
+                retval = rpm_suspend(dev, rpmflags);
+                goto out;
+        }
+
+        /* Carry out an asynchronous or a synchronous idle notification. */
+        if (rpmflags & RPM_ASYNC) {
+                dev->power.request = RPM_REQ_IDLE;
+                if (!dev->power.request_pending) {
+                        dev->power.request_pending = true;
+                        queue_work(pm_wq, &dev->power.work);
                 }
+                goto out;
         }
 
         dev->power.idle_notification = true;
 
-        if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) {
-                spin_unlock_irq(&dev->power.lock);
-
-                dev->bus->pm->runtime_idle(dev);
-
-                spin_lock_irq(&dev->power.lock);
-        } else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle) {
-                spin_unlock_irq(&dev->power.lock);
-
-                dev->type->pm->runtime_idle(dev);
+        if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle)
+                callback = dev->bus->pm->runtime_idle;
+        else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle)
+                callback = dev->type->pm->runtime_idle;
+        else if (dev->class && dev->class->pm)
+                callback = dev->class->pm->runtime_idle;
+        else
+                callback = NULL;
 
-                spin_lock_irq(&dev->power.lock);
-        } else if (dev->class && dev->class->pm
-            && dev->class->pm->runtime_idle) {
+        if (callback) {
                 spin_unlock_irq(&dev->power.lock);
 
-                dev->class->pm->runtime_idle(dev);
+                callback(dev);
 
                 spin_lock_irq(&dev->power.lock);
         }
@@ -108,113 +238,99 @@ static int __pm_runtime_idle(struct device *dev)
 }
 
 /**
- * pm_runtime_idle - Notify device bus type if the device can be suspended.
- * @dev: Device to notify the bus type about.
+ * rpm_callback - Run a given runtime PM callback for a given device.
+ * @cb: Runtime PM callback to run.
+ * @dev: Device to run the callback for.
  */
-int pm_runtime_idle(struct device *dev)
+static int rpm_callback(int (*cb)(struct device *), struct device *dev)
+        __releases(&dev->power.lock) __acquires(&dev->power.lock)
 {
         int retval;
 
-        spin_lock_irq(&dev->power.lock);
-        retval = __pm_runtime_idle(dev);
-        spin_unlock_irq(&dev->power.lock);
+        if (!cb)
+                return -ENOSYS;
 
-        return retval;
-}
-EXPORT_SYMBOL_GPL(pm_runtime_idle);
-
-
-/**
- * update_pm_runtime_accounting - Update the time accounting of power states
- * @dev: Device to update the accounting for
- *
- * In order to be able to have time accounting of the various power states
- * (as used by programs such as PowerTOP to show the effectiveness of runtime
- * PM), we need to track the time spent in each state.
- * update_pm_runtime_accounting must be called each time before the
- * runtime_status field is updated, to account the time in the old state
- * correctly.
- */
-void update_pm_runtime_accounting(struct device *dev)
-{
-        unsigned long now = jiffies;
-        int delta;
-
-        delta = now - dev->power.accounting_timestamp;
-
-        if (delta < 0)
-                delta = 0;
+        spin_unlock_irq(&dev->power.lock);
 
-        dev->power.accounting_timestamp = now;
+        retval = cb(dev);
 
-        if (dev->power.disable_depth > 0)
-                return;
-
-        if (dev->power.runtime_status == RPM_SUSPENDED)
-                dev->power.suspended_jiffies += delta;
-        else
-                dev->power.active_jiffies += delta;
-}
+        spin_lock_irq(&dev->power.lock);
+        dev->power.runtime_error = retval;
 
-static void __update_runtime_status(struct device *dev, enum rpm_status status)
-{
-        update_pm_runtime_accounting(dev);
-        dev->power.runtime_status = status;
+        return retval;
 }
 
 /**
- * __pm_runtime_suspend - Carry out run-time suspend of given device.
+ * rpm_suspend - Carry out run-time suspend of given device.
  * @dev: Device to suspend.
- * @from_wq: If set, the function has been called via pm_wq.
+ * @rpmflags: Flag bits.
  *
- * Check if the device can be suspended and run the ->runtime_suspend() callback
- * provided by its bus type.  If another suspend has been started earlier, wait
- * for it to finish.  If an idle notification or suspend request is pending or
- * scheduled, cancel it.
+ * Check if the device's run-time PM status allows it to be suspended.  If
+ * another suspend has been started earlier, either return immediately or wait
+ * for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC flags.  Cancel a
+ * pending idle notification.  If the RPM_ASYNC flag is set then queue a
+ * suspend request; otherwise run the ->runtime_suspend() callback directly.
+ * If a deferred resume was requested while the callback was running then carry
+ * it out; otherwise send an idle notification for the device (if the suspend
+ * failed) or for its parent (if the suspend succeeded).
  *
  * This function must be called under dev->power.lock with interrupts disabled.
  */
-int __pm_runtime_suspend(struct device *dev, bool from_wq)
+static int rpm_suspend(struct device *dev, int rpmflags)
         __releases(&dev->power.lock) __acquires(&dev->power.lock)
 {
+        int (*callback)(struct device *);
         struct device *parent = NULL;
-        bool notify = false;
-        int retval = 0;
+        int retval;
 
-        dev_dbg(dev, "__pm_runtime_suspend()%s!\n",
-                from_wq ? " from workqueue" : "");
+        dev_dbg(dev, "%s flags 0x%x\n", __func__, rpmflags);
 
  repeat:
-        if (dev->power.runtime_error) {
-                retval = -EINVAL;
-                goto out;
-        }
+        retval = rpm_check_suspend_allowed(dev);
 
-        /* Pending resume requests take precedence over us. */
-        if (dev->power.request_pending
-            && dev->power.request == RPM_REQ_RESUME) {
+        if (retval < 0)
+                ;       /* Conditions are wrong. */
+
+        /* Synchronous suspends are not allowed in the RPM_RESUMING state. */
+        else if (dev->power.runtime_status == RPM_RESUMING &&
+            !(rpmflags & RPM_ASYNC))
                 retval = -EAGAIN;
+        if (retval)
                 goto out;
+
+        /* If the autosuspend_delay time hasn't expired yet, reschedule. */
+        if ((rpmflags & RPM_AUTO)
+            && dev->power.runtime_status != RPM_SUSPENDING) {
+                unsigned long expires = pm_runtime_autosuspend_expiration(dev);
+
+                if (expires != 0) {
+                        /* Pending requests need to be canceled. */
+                        dev->power.request = RPM_REQ_NONE;
+
+                        /*
+                         * Optimization: If the timer is already running and is
+                         * set to expire at or before the autosuspend delay,
+                         * avoid the overhead of resetting it.  Just let it
+                         * expire; pm_suspend_timer_fn() will take care of the
+                         * rest.
+                         */
+                        if (!(dev->power.timer_expires && time_before_eq(
+                            dev->power.timer_expires, expires))) {
+                                dev->power.timer_expires = expires;
+                                mod_timer(&dev->power.suspend_timer, expires);
+                        }
+                        dev->power.timer_autosuspends = 1;
+                        goto out;
+                }
         }
 
         /* Other scheduled or pending requests need to be canceled. */
         pm_runtime_cancel_pending(dev);
 
-        if (dev->power.runtime_status == RPM_SUSPENDED)
-                retval = 1;
-        else if (dev->power.runtime_status == RPM_RESUMING
-            || dev->power.disable_depth > 0
-            || atomic_read(&dev->power.usage_count) > 0)
-                retval = -EAGAIN;
-        else if (!pm_children_suspended(dev))
-                retval = -EBUSY;
-        if (retval)
-                goto out;
-
         if (dev->power.runtime_status == RPM_SUSPENDING) {
                 DEFINE_WAIT(wait);
 
-                if (from_wq) {
+                if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
                         retval = -EINPROGRESS;
                         goto out;
                 }
@@ -236,46 +352,42 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq)
                 goto repeat;
         }
 
-        __update_runtime_status(dev, RPM_SUSPENDING);
         dev->power.deferred_resume = false;
+        if (dev->power.no_callbacks)
+                goto no_callback;       /* Assume success. */
+
+        /* Carry out an asynchronous or a synchronous suspend. */
+        if (rpmflags & RPM_ASYNC) {
+                dev->power.request = (rpmflags & RPM_AUTO) ?
+                    RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND;
+                if (!dev->power.request_pending) {
+                        dev->power.request_pending = true;
+                        queue_work(pm_wq, &dev->power.work);
+                }
+                goto out;
+        }
 
-        if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) {
-                spin_unlock_irq(&dev->power.lock);
-
-                retval = dev->bus->pm->runtime_suspend(dev);
-
-                spin_lock_irq(&dev->power.lock);
-                dev->power.runtime_error = retval;
-        } else if (dev->type && dev->type->pm
-            && dev->type->pm->runtime_suspend) {
-                spin_unlock_irq(&dev->power.lock);
-
-                retval = dev->type->pm->runtime_suspend(dev);
-
-                spin_lock_irq(&dev->power.lock);
-                dev->power.runtime_error = retval;
-        } else if (dev->class && dev->class->pm
-            && dev->class->pm->runtime_suspend) {
-                spin_unlock_irq(&dev->power.lock);
-
-                retval = dev->class->pm->runtime_suspend(dev);
+        __update_runtime_status(dev, RPM_SUSPENDING);
 
-                spin_lock_irq(&dev->power.lock);
-                dev->power.runtime_error = retval;
-        } else {
-                retval = -ENOSYS;
-        }
+        if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
+                callback = dev->bus->pm->runtime_suspend;
+        else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend)
+                callback = dev->type->pm->runtime_suspend;
+        else if (dev->class && dev->class->pm)
+                callback = dev->class->pm->runtime_suspend;
+        else
+                callback = NULL;
 
+        retval = rpm_callback(callback, dev);
         if (retval) {
                 __update_runtime_status(dev, RPM_ACTIVE);
-                if (retval == -EAGAIN || retval == -EBUSY) {
-                        if (dev->power.timer_expires == 0)
-                                notify = true;
+                dev->power.deferred_resume = 0;
+                if (retval == -EAGAIN || retval == -EBUSY)
                         dev->power.runtime_error = 0;
-                } else {
+                else
                         pm_runtime_cancel_pending(dev);
-                }
         } else {
+ no_callback:
                 __update_runtime_status(dev, RPM_SUSPENDED);
                 pm_runtime_deactivate_timer(dev);
 
@@ -287,14 +399,11 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq)
         wake_up_all(&dev->power.wait_queue);
 
         if (dev->power.deferred_resume) {
-                __pm_runtime_resume(dev, false);
+                rpm_resume(dev, 0);
                 retval = -EAGAIN;
                 goto out;
         }
 
-        if (notify)
-                __pm_runtime_idle(dev);
-
         if (parent && !parent->power.ignore_children) {
                 spin_unlock_irq(&dev->power.lock);
 
@@ -304,72 +413,69 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq)
         }
 
  out:
-        dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval);
-
-        return retval;
-}
-
-/**
- * pm_runtime_suspend - Carry out run-time suspend of given device.
- * @dev: Device to suspend.
- */
-int pm_runtime_suspend(struct device *dev)
-{
-        int retval;
-
-        spin_lock_irq(&dev->power.lock);
-        retval = __pm_runtime_suspend(dev, false);
-        spin_unlock_irq(&dev->power.lock);
+        dev_dbg(dev, "%s returns %d\n", __func__, retval);
 
         return retval;
 }
-EXPORT_SYMBOL_GPL(pm_runtime_suspend);
 
 /**
- * __pm_runtime_resume - Carry out run-time resume of given device.
+ * rpm_resume - Carry out run-time resume of given device.
  * @dev: Device to resume.
- * @from_wq: If set, the function has been called via pm_wq.
+ * @rpmflags: Flag bits.
  *
- * Check if the device can be woken up and run the ->runtime_resume() callback
- * provided by its bus type.  If another resume has been started earlier, wait
- * for it to finish.  If there's a suspend running in parallel with this
- * function, wait for it to finish and resume the device.  Cancel any scheduled
- * or pending requests.
+ * Check if the device's run-time PM status allows it to be resumed.  Cancel
+ * any scheduled or pending requests.  If another resume has been started
+ * earlier, either return imediately or wait for it to finish, depending on the
+ * RPM_NOWAIT and RPM_ASYNC flags.  Similarly, if there's a suspend running in
+ * parallel with this function, either tell the other process to resume after
+ * suspending (deferred_resume) or wait for it to finish.  If the RPM_ASYNC
+ * flag is set then queue a resume request; otherwise run the
+ * ->runtime_resume() callback directly.  Queue an idle notification for the
+ * device if the resume succeeded.
  *
  * This function must be called under dev->power.lock with interrupts disabled.
  */
-int __pm_runtime_resume(struct device *dev, bool from_wq)
+static int rpm_resume(struct device *dev, int rpmflags)
         __releases(&dev->power.lock) __acquires(&dev->power.lock)
 {
+        int (*callback)(struct device *);
         struct device *parent = NULL;
         int retval = 0;
 
-        dev_dbg(dev, "__pm_runtime_resume()%s!\n",
-                from_wq ? " from workqueue" : "");
+        dev_dbg(dev, "%s flags 0x%x\n", __func__, rpmflags);
 
  repeat:
-        if (dev->power.runtime_error) {
+        if (dev->power.runtime_error)
                 retval = -EINVAL;
+        else if (dev->power.disable_depth > 0)
+                retval = -EAGAIN;
+        if (retval)
                 goto out;
-        }
 
-        pm_runtime_cancel_pending(dev);
+        /*
+         * Other scheduled or pending requests need to be canceled.  Small
+         * optimization: If an autosuspend timer is running, leave it running
+         * rather than cancelling it now only to restart it again in the near
+         * future.
+         */
+        dev->power.request = RPM_REQ_NONE;
+        if (!dev->power.timer_autosuspends)
+                pm_runtime_deactivate_timer(dev);
 
-        if (dev->power.runtime_status == RPM_ACTIVE)
+        if (dev->power.runtime_status == RPM_ACTIVE) {
                 retval = 1;
-        else if (dev->power.disable_depth > 0)
-                retval = -EAGAIN;
-        if (retval)
                 goto out;
+        }
 
         if (dev->power.runtime_status == RPM_RESUMING
             || dev->power.runtime_status == RPM_SUSPENDING) {
                 DEFINE_WAIT(wait);
 
-                if (from_wq) {
+                if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
                         if (dev->power.runtime_status == RPM_SUSPENDING)
                                 dev->power.deferred_resume = true;
-                        retval = -EINPROGRESS;
+                        else
+                                retval = -EINPROGRESS;
                         goto out;
                 }
 
@@ -391,6 +497,34 @@ int __pm_runtime_resume(struct device *dev, bool from_wq)
                 goto repeat;
         }
 
+        /*
+         * See if we can skip waking up the parent.  This is safe only if
+         * power.no_callbacks is set, because otherwise we don't know whether
+         * the resume will actually succeed.
+         */
+        if (dev->power.no_callbacks && !parent && dev->parent) {
+                spin_lock(&dev->parent->power.lock);
+                if (dev->parent->power.disable_depth > 0
+                    || dev->parent->power.ignore_children
+                    || dev->parent->power.runtime_status == RPM_ACTIVE) {
+                        atomic_inc(&dev->parent->power.child_count);
+                        spin_unlock(&dev->parent->power.lock);
+                        goto no_callback;       /* Assume success. */
+                }
+                spin_unlock(&dev->parent->power.lock);
+        }
+
+        /* Carry out an asynchronous or a synchronous resume. */
+        if (rpmflags & RPM_ASYNC) {
+                dev->power.request = RPM_REQ_RESUME;
+                if (!dev->power.request_pending) {
+                        dev->power.request_pending = true;
+                        queue_work(pm_wq, &dev->power.work);
+                }
+                retval = 0;
+                goto out;
+        }
+
         if (!parent && dev->parent) {
                 /*
                  * Increment the parent's resume counter and resume it if
@@ -408,7 +542,7 @@ int __pm_runtime_resume(struct device *dev, bool from_wq)
                  */
                 if (!parent->power.disable_depth
                     && !parent->power.ignore_children) {
-                        __pm_runtime_resume(parent, false);
+                        rpm_resume(parent, 0);
                         if (parent->power.runtime_status != RPM_ACTIVE)
                                 retval = -EBUSY;
                 }
@@ -420,39 +554,26 @@ int __pm_runtime_resume(struct device *dev, bool from_wq)
                 goto repeat;
         }
 
-        __update_runtime_status(dev, RPM_RESUMING);
-
-        if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) {
-                spin_unlock_irq(&dev->power.lock);
-
-                retval = dev->bus->pm->runtime_resume(dev);
-
-                spin_lock_irq(&dev->power.lock);
-                dev->power.runtime_error = retval;
-        } else if (dev->type && dev->type->pm
-            && dev->type->pm->runtime_resume) {
-                spin_unlock_irq(&dev->power.lock);
-
-                retval = dev->type->pm->runtime_resume(dev);
+        if (dev->power.no_callbacks)
+                goto no_callback;       /* Assume success. */
 
-                spin_lock_irq(&dev->power.lock);
-                dev->power.runtime_error = retval;
-        } else if (dev->class && dev->class->pm
-            && dev->class->pm->runtime_resume) {
-                spin_unlock_irq(&dev->power.lock);
-
-                retval = dev->class->pm->runtime_resume(dev);
+        __update_runtime_status(dev, RPM_RESUMING);
 
-                spin_lock_irq(&dev->power.lock);
-                dev->power.runtime_error = retval;
-        } else {
-                retval = -ENOSYS;
-        }
+        if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
+                callback = dev->bus->pm->runtime_resume;
+        else if (dev->type && dev->type->pm && dev->type->pm->runtime_resume)
+                callback = dev->type->pm->runtime_resume;
+        else if (dev->class && dev->class->pm)
+                callback = dev->class->pm->runtime_resume;
+        else
+                callback = NULL;
 
+        retval = rpm_callback(callback, dev);
         if (retval) {
                 __update_runtime_status(dev, RPM_SUSPENDED);
                 pm_runtime_cancel_pending(dev);
         } else {
+ no_callback:
                 __update_runtime_status(dev, RPM_ACTIVE);
                 if (parent)
                         atomic_inc(&parent->power.child_count);
@@ -460,7 +581,7 @@ int __pm_runtime_resume(struct device *dev, bool from_wq)
         wake_up_all(&dev->power.wait_queue);
 
         if (!retval)
-                __pm_request_idle(dev);
+                rpm_idle(dev, RPM_ASYNC);
 
  out:
         if (parent) {
@@ -471,28 +592,12 @@ int __pm_runtime_resume(struct device *dev, bool from_wq)
                 spin_lock_irq(&dev->power.lock);
         }
 
-        dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval);
+        dev_dbg(dev, "%s returns %d\n", __func__, retval);
 
         return retval;
 }
 
 /**
- * pm_runtime_resume - Carry out run-time resume of given device.
- * @dev: Device to suspend.
- */
-int pm_runtime_resume(struct device *dev)
-{
-        int retval;
-
-        spin_lock_irq(&dev->power.lock);
-        retval = __pm_runtime_resume(dev, false);
-        spin_unlock_irq(&dev->power.lock);
-
-        return retval;
-}
-EXPORT_SYMBOL_GPL(pm_runtime_resume);
-
-/**
  * pm_runtime_work - Universal run-time PM work function.
  * @work: Work structure used for scheduling the execution of this function.
  *
@@ -517,13 +622,16 @@ static void pm_runtime_work(struct work_struct *work)
         case RPM_REQ_NONE:
                 break;
         case RPM_REQ_IDLE:
-                __pm_runtime_idle(dev);
+                rpm_idle(dev, RPM_NOWAIT);
                 break;
         case RPM_REQ_SUSPEND:
-                __pm_runtime_suspend(dev, true);
+                rpm_suspend(dev, RPM_NOWAIT);
+                break;
+        case RPM_REQ_AUTOSUSPEND:
+                rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO);
                 break;
         case RPM_REQ_RESUME:
-                __pm_runtime_resume(dev, true);
+                rpm_resume(dev, RPM_NOWAIT);
                 break;
         }
 
@@ -532,117 +640,10 @@ static void pm_runtime_work(struct work_struct *work)
 }
 
 /**
- * __pm_request_idle - Submit an idle notification request for given device.
- * @dev: Device to handle.
- *
- * Check if the device's run-time PM status is correct for suspending the device
- * and queue up a request to run __pm_runtime_idle() for it.
- *
- * This function must be called under dev->power.lock with interrupts disabled.
- */
-static int __pm_request_idle(struct device *dev)
-{
-        int retval = 0;
-
-        if (dev->power.runtime_error)
-                retval = -EINVAL;
-        else if (atomic_read(&dev->power.usage_count) > 0
-            || dev->power.disable_depth > 0
-            || dev->power.runtime_status == RPM_SUSPENDED
-            || dev->power.runtime_status == RPM_SUSPENDING)
-                retval = -EAGAIN;
-        else if (!pm_children_suspended(dev))
-                retval = -EBUSY;
-        if (retval)
-                return retval;
-
-        if (dev->power.request_pending) {
-                /* Any requests other then RPM_REQ_IDLE take precedence. */
-                if (dev->power.request == RPM_REQ_NONE)
-                        dev->power.request = RPM_REQ_IDLE;
-                else if (dev->power.request != RPM_REQ_IDLE)
-                        retval = -EAGAIN;
-                return retval;
-        }
-
-        dev->power.request = RPM_REQ_IDLE;
-        dev->power.request_pending = true;
-        queue_work(pm_wq, &dev->power.work);
-
-        return retval;
-}
-
-/**
- * pm_request_idle - Submit an idle notification request for given device.
- * @dev: Device to handle.
- */
-int pm_request_idle(struct device *dev)
-{
-        unsigned long flags;
-        int retval;
-
-        spin_lock_irqsave(&dev->power.lock, flags);
-        retval = __pm_request_idle(dev);
-        spin_unlock_irqrestore(&dev->power.lock, flags);
-
-        return retval;
-}
-EXPORT_SYMBOL_GPL(pm_request_idle);
-
-/**
- * __pm_request_suspend - Submit a suspend request for given device.
- * @dev: Device to suspend.
- *
- * This function must be called under dev->power.lock with interrupts disabled.
- */
-static int __pm_request_suspend(struct device *dev)
-{
-        int retval = 0;
-
-        if (dev->power.runtime_error)
-                return -EINVAL;
-
-        if (dev->power.runtime_status == RPM_SUSPENDED)
-                retval = 1;
-        else if (atomic_read(&dev->power.usage_count) > 0
-            || dev->power.disable_depth > 0)
-                retval = -EAGAIN;
-        else if (dev->power.runtime_status == RPM_SUSPENDING)
-                retval = -EINPROGRESS;
-        else if (!pm_children_suspended(dev))
-                retval = -EBUSY;
-        if (retval < 0)
-                return retval;
-
-        pm_runtime_deactivate_timer(dev);
-
-        if (dev->power.request_pending) {
-                /*
-                 * Pending resume requests take precedence over us, but we can
-                 * overtake any other pending request.
-                 */
-                if (dev->power.request == RPM_REQ_RESUME)
-                        retval = -EAGAIN;
-                else if (dev->power.request != RPM_REQ_SUSPEND)
-                        dev->power.request = retval ?
-                                                RPM_REQ_NONE : RPM_REQ_SUSPEND;
-                return retval;
-        } else if (retval) {
-                return retval;
-        }
-
-        dev->power.request = RPM_REQ_SUSPEND;
-        dev->power.request_pending = true;
-        queue_work(pm_wq, &dev->power.work);
-
-        return 0;
-}
-
-/**
  * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
  * @data: Device pointer passed by pm_schedule_suspend().
  *
- * Check if the time is right and execute __pm_request_suspend() in that case.
+ * Check if the time is right and queue a suspend request.
  */
 static void pm_suspend_timer_fn(unsigned long data)
 {
@@ -656,7 +657,8 @@ static void pm_suspend_timer_fn(unsigned long data)
         /* If 'expire' is after 'jiffies' we've been called too early. */
         if (expires > 0 && !time_after(expires, jiffies)) {
                 dev->power.timer_expires = 0;
-                __pm_request_suspend(dev);
+                rpm_suspend(dev, dev->power.timer_autosuspends ?
+                    (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC);
         }
 
         spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -670,47 +672,25 @@ static void pm_suspend_timer_fn(unsigned long data)
 int pm_schedule_suspend(struct device *dev, unsigned int delay)
 {
         unsigned long flags;
-        int retval = 0;
+        int retval;
 
         spin_lock_irqsave(&dev->power.lock, flags);
 
-        if (dev->power.runtime_error) {
-                retval = -EINVAL;
-                goto out;
-        }
-
         if (!delay) {
-                retval = __pm_request_suspend(dev);
+                retval = rpm_suspend(dev, RPM_ASYNC);
                 goto out;
         }
 
-        pm_runtime_deactivate_timer(dev);
-
-        if (dev->power.request_pending) {
-                /*
-                 * Pending resume requests take precedence over us, but any
-                 * other pending requests have to be canceled.
-                 */
-                if (dev->power.request == RPM_REQ_RESUME) {
-                        retval = -EAGAIN;
-                        goto out;
-                }
-                dev->power.request = RPM_REQ_NONE;
-        }
-
-        if (dev->power.runtime_status == RPM_SUSPENDED)
-                retval = 1;
-        else if (atomic_read(&dev->power.usage_count) > 0
-            || dev->power.disable_depth > 0)
-                retval = -EAGAIN;
-        else if (!pm_children_suspended(dev))
-                retval = -EBUSY;
+        retval = rpm_check_suspend_allowed(dev);
         if (retval)
                 goto out;
 
+        /* Other scheduled or pending requests need to be canceled. */
+        pm_runtime_cancel_pending(dev);
+
         dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
-        if (!dev->power.timer_expires)
-                dev->power.timer_expires = 1;
+        dev->power.timer_expires += !dev->power.timer_expires;
+        dev->power.timer_autosuspends = 0;
         mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
 
  out:
@@ -721,103 +701,88 @@ int pm_schedule_suspend(struct device *dev, unsigned int delay)
 EXPORT_SYMBOL_GPL(pm_schedule_suspend);
 
 /**
- * pm_request_resume - Submit a resume request for given device.
- * @dev: Device to resume.
+ * __pm_runtime_idle - Entry point for run-time idle operations.
+ * @dev: Device to send idle notification for.
+ * @rpmflags: Flag bits.
  *
- * This function must be called under dev->power.lock with interrupts disabled.
+ * If the RPM_GET_PUT flag is set, decrement the device's usage count and
+ * return immediately if it is larger than zero.  Then carry out an idle
+ * notification, either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set.
  */
-static int __pm_request_resume(struct device *dev)
+int __pm_runtime_idle(struct device *dev, int rpmflags)
 {
-        int retval = 0;
-
-        if (dev->power.runtime_error)
-                return -EINVAL;
-
-        if (dev->power.runtime_status == RPM_ACTIVE)
-                retval = 1;
-        else if (dev->power.runtime_status == RPM_RESUMING)
-                retval = -EINPROGRESS;
-        else if (dev->power.disable_depth > 0)
-                retval = -EAGAIN;
-        if (retval < 0)
-                return retval;
-
-        pm_runtime_deactivate_timer(dev);
+        unsigned long flags;
+        int retval;
 
-        if (dev->power.runtime_status == RPM_SUSPENDING) {
-                dev->power.deferred_resume = true;
-                return retval;
+        if (rpmflags & RPM_GET_PUT) {
+                if (!atomic_dec_and_test(&dev->power.usage_count))
+                        return 0;
         }
-        if (dev->power.request_pending) {
-                /* If non-resume request is pending, we can overtake it. */
-                dev->power.request = retval ? RPM_REQ_NONE : RPM_REQ_RESUME;
-                return retval;
-        }
-        if (retval)
-                return retval;
 
-        dev->power.request = RPM_REQ_RESUME;
-        dev->power.request_pending = true;
-        queue_work(pm_wq, &dev->power.work);
+        spin_lock_irqsave(&dev->power.lock, flags);
+        retval = rpm_idle(dev, rpmflags);
+        spin_unlock_irqrestore(&dev->power.lock, flags);
 
         return retval;
 }
+EXPORT_SYMBOL_GPL(__pm_runtime_idle);
 
 /**
- * pm_request_resume - Submit a resume request for given device.
- * @dev: Device to resume.
+ * __pm_runtime_suspend - Entry point for run-time put/suspend operations.
+ * @dev: Device to suspend.
+ * @rpmflags: Flag bits.
+ *
+ * If the RPM_GET_PUT flag is set, decrement the device's usage count and
+ * return immediately if it is larger than zero.  Then carry out a suspend,
+ * either synchronous or asynchronous.
+ *
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set.
  */
-int pm_request_resume(struct device *dev)
+int __pm_runtime_suspend(struct device *dev, int rpmflags)
 {
         unsigned long flags;
         int retval;
 
+        if (rpmflags & RPM_GET_PUT) {
+                if (!atomic_dec_and_test(&dev->power.usage_count))
+                        return 0;
+        }
+
         spin_lock_irqsave(&dev->power.lock, flags);
-        retval = __pm_request_resume(dev);
+        retval = rpm_suspend(dev, rpmflags);
         spin_unlock_irqrestore(&dev->power.lock, flags);
 
         return retval;
 }
-EXPORT_SYMBOL_GPL(pm_request_resume);
+EXPORT_SYMBOL_GPL(__pm_runtime_suspend);
 
 /**
- * __pm_runtime_get - Reference count a device and wake it up, if necessary.
- * @dev: Device to handle.
- * @sync: If set and the device is suspended, resume it synchronously.
+ * __pm_runtime_resume - Entry point for run-time resume operations.
+ * @dev: Device to resume.
+ * @rpmflags: Flag bits.
+ *
+ * If the RPM_GET_PUT flag is set, increment the device's usage count.  Then
+ * carry out a resume, either synchronous or asynchronous.
  *
- * Increment the usage count of the device and resume it or submit a resume
- * request for it, depending on the value of @sync.
+ * This routine may be called in atomic context if the RPM_ASYNC flag is set.
  */
-int __pm_runtime_get(struct device *dev, bool sync)
+int __pm_runtime_resume(struct device *dev, int rpmflags)
 {
+        unsigned long flags;
         int retval;
 
-        atomic_inc(&dev->power.usage_count);
-        retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev);
+        if (rpmflags & RPM_GET_PUT)
+                atomic_inc(&dev->power.usage_count);
 
-        return retval;
-}
-EXPORT_SYMBOL_GPL(__pm_runtime_get);
-
-/**
- * __pm_runtime_put - Decrement the device's usage counter and notify its bus.
- * @dev: Device to handle.
- * @sync: If the device's bus type is to be notified, do that synchronously.
- *
- * Decrement the usage count of the device and if it reaches zero, carry out a
- * synchronous idle notification or submit an idle notification request for it,
- * depending on the value of @sync.
- */
-int __pm_runtime_put(struct device *dev, bool sync)
-{
-        int retval = 0;
-
-        if (atomic_dec_and_test(&dev->power.usage_count))
-                retval = sync ? pm_runtime_idle(dev) : pm_request_idle(dev);
+        spin_lock_irqsave(&dev->power.lock, flags);
+        retval = rpm_resume(dev, rpmflags);
+        spin_unlock_irqrestore(&dev->power.lock, flags);
 
         return retval;
 }
-EXPORT_SYMBOL_GPL(__pm_runtime_put);
+EXPORT_SYMBOL_GPL(__pm_runtime_resume);
 
 /**
  * __pm_runtime_set_status - Set run-time PM status of a device.
@@ -968,7 +933,7 @@ int pm_runtime_barrier(struct device *dev)
 
         if (dev->power.request_pending
             && dev->power.request == RPM_REQ_RESUME) {
-                __pm_runtime_resume(dev, false);
+                rpm_resume(dev, 0);
                 retval = 1;
         }
 
@@ -1017,7 +982,7 @@ void __pm_runtime_disable(struct device *dev, bool check_resume)
                  */
                 pm_runtime_get_noresume(dev);
 
-                __pm_runtime_resume(dev, false);
+                rpm_resume(dev, 0);
 
                 pm_runtime_put_noidle(dev);
         }
@@ -1065,7 +1030,7 @@ void pm_runtime_forbid(struct device *dev)
 
         dev->power.runtime_auto = false;
         atomic_inc(&dev->power.usage_count);
-        __pm_runtime_resume(dev, false);
+        rpm_resume(dev, 0);
 
  out:
         spin_unlock_irq(&dev->power.lock);
@@ -1086,7 +1051,7 @@ void pm_runtime_allow(struct device *dev)
 
         dev->power.runtime_auto = true;
         if (atomic_dec_and_test(&dev->power.usage_count))
-                __pm_runtime_idle(dev);
+                rpm_idle(dev, RPM_AUTO);
 
  out:
         spin_unlock_irq(&dev->power.lock);
@@ -1094,13 +1059,110 @@ void pm_runtime_allow(struct device *dev)
 EXPORT_SYMBOL_GPL(pm_runtime_allow);
 
 /**
+ * pm_runtime_no_callbacks - Ignore run-time PM callbacks for a device.
+ * @dev: Device to handle.
+ *
+ * Set the power.no_callbacks flag, which tells the PM core that this
+ * device is power-managed through its parent and has no run-time PM
+ * callbacks of its own.  The run-time sysfs attributes will be removed.
+ *
+ */
+void pm_runtime_no_callbacks(struct device *dev)
+{
+        spin_lock_irq(&dev->power.lock);
+        dev->power.no_callbacks = 1;
+        spin_unlock_irq(&dev->power.lock);
+        if (device_is_registered(dev))
+                rpm_sysfs_remove(dev);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks);
+
+/**
+ * update_autosuspend - Handle a change to a device's autosuspend settings.
+ * @dev: Device to handle.
+ * @old_delay: The former autosuspend_delay value.
+ * @old_use: The former use_autosuspend value.
+ *
+ * Prevent runtime suspend if the new delay is negative and use_autosuspend is
+ * set; otherwise allow it.  Send an idle notification if suspends are allowed.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static void update_autosuspend(struct device *dev, int old_delay, int old_use)
+{
+        int delay = dev->power.autosuspend_delay;
+
+        /* Should runtime suspend be prevented now? */
+        if (dev->power.use_autosuspend && delay < 0) {
+
+                /* If it used to be allowed then prevent it. */
+                if (!old_use || old_delay >= 0) {
+                        atomic_inc(&dev->power.usage_count);
+                        rpm_resume(dev, 0);
+                }
+        }
+
+        /* Runtime suspend should be allowed now. */
+        else {
+
+                /* If it used to be prevented then allow it. */
+                if (old_use && old_delay < 0)
+                        atomic_dec(&dev->power.usage_count);
+
+                /* Maybe we can autosuspend now. */
+                rpm_idle(dev, RPM_AUTO);
+        }
+}
+
+/**
+ * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value.
+ * @dev: Device to handle.
+ * @delay: Value of the new delay in milliseconds.
+ *
+ * Set the device's power.autosuspend_delay value.  If it changes to negative
+ * and the power.use_autosuspend flag is set, prevent run-time suspends.  If it
+ * changes the other way, allow run-time suspends.
+ */
+void pm_runtime_set_autosuspend_delay(struct device *dev, int delay)
+{
+        int old_delay, old_use;
+
+        spin_lock_irq(&dev->power.lock);
+        old_delay = dev->power.autosuspend_delay;
+        old_use = dev->power.use_autosuspend;
+        dev->power.autosuspend_delay = delay;
+        update_autosuspend(dev, old_delay, old_use);
+        spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay);
+
+/**
+ * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag.
+ * @dev: Device to handle.
+ * @use: New value for use_autosuspend.
+ *
+ * Set the device's power.use_autosuspend flag, and allow or prevent run-time
+ * suspends as needed.
+ */
+void __pm_runtime_use_autosuspend(struct device *dev, bool use)
+{
+        int old_delay, old_use;
+
+        spin_lock_irq(&dev->power.lock);
+        old_delay = dev->power.autosuspend_delay;
+        old_use = dev->power.use_autosuspend;
+        dev->power.use_autosuspend = use;
+        update_autosuspend(dev, old_delay, old_use);
+        spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend);
+
+/**
  * pm_runtime_init - Initialize run-time PM fields in given device object.
  * @dev: Device object to initialize.
  */
 void pm_runtime_init(struct device *dev)
 {
-        spin_lock_init(&dev->power.lock);
-
         dev->power.runtime_status = RPM_SUSPENDED;
         dev->power.idle_notification = false;