1 files changed, 140 insertions, 235 deletions

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 0c1db879544b..d7b5d84c235c 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -2,6 +2,7 @@
  * 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.
  */
@@ -11,8 +12,6 @@
 #include <linux/jiffies.h>
 
 static int __pm_runtime_resume(struct device *dev, int rpmflags);
-static int __pm_request_idle(struct device *dev);
-static int __pm_request_resume(struct device *dev);
 
 /**
  * update_pm_runtime_accounting - Update the time accounting of power states
@@ -79,40 +78,84 @@ static void pm_runtime_cancel_pending(struct device *dev)
 }
 
 /**
- * __pm_runtime_idle - Notify device bus type if the device can be suspended.
- * @dev: Device to notify the bus type about.
- *
- * This function must be called under dev->power.lock with interrupts disabled.
+ * rpm_check_suspend_allowed - Test whether a device may be suspended.
+ * @dev: Device to test.
  */
-static int __pm_runtime_idle(struct device *dev)
-        __releases(&dev->power.lock) __acquires(&dev->power.lock)
+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;
+}
+
+
+/**
+ * __pm_runtime_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 __pm_runtime_idle(struct device *dev, int rpmflags)
+        __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+        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;
+
+        /* 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;
@@ -154,7 +197,7 @@ int pm_runtime_idle(struct device *dev)
         int retval;
 
         spin_lock_irq(&dev->power.lock);
-        retval = __pm_runtime_idle(dev);
+        retval = __pm_runtime_idle(dev, 0);
         spin_unlock_irq(&dev->power.lock);
 
         return retval;
@@ -166,11 +209,14 @@ EXPORT_SYMBOL_GPL(pm_runtime_idle);
  * @dev: Device to suspend.
  * @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,
- * either return immediately or wait for it to finish, depending on the
- * RPM_NOWAIT flag.  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.
  */
@@ -179,41 +225,30 @@ static int __pm_runtime_suspend(struct device *dev, int rpmflags)
 {
         struct device *parent = NULL;
         bool notify = false;
-        int retval = 0;
+        int retval;
 
         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;
-        }
 
         /* 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 (rpmflags & RPM_NOWAIT) {
+                if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
                         retval = -EINPROGRESS;
                         goto out;
                 }
@@ -235,6 +270,16 @@ static int __pm_runtime_suspend(struct device *dev, int rpmflags)
                 goto repeat;
         }
 
+        /* Carry out an asynchronous or a synchronous suspend. */
+        if (rpmflags & RPM_ASYNC) {
+                dev->power.request = RPM_REQ_SUSPEND;
+                if (!dev->power.request_pending) {
+                        dev->power.request_pending = true;
+                        queue_work(pm_wq, &dev->power.work);
+                }
+                goto out;
+        }
+
         __update_runtime_status(dev, RPM_SUSPENDING);
         dev->power.deferred_resume = false;
 
@@ -267,6 +312,7 @@ static int __pm_runtime_suspend(struct device *dev, int rpmflags)
 
         if (retval) {
                 __update_runtime_status(dev, RPM_ACTIVE);
+                dev->power.deferred_resume = 0;
                 if (retval == -EAGAIN || retval == -EBUSY) {
                         if (dev->power.timer_expires == 0)
                                 notify = true;
@@ -292,7 +338,7 @@ static int __pm_runtime_suspend(struct device *dev, int rpmflags)
         }
 
         if (notify)
-                __pm_runtime_idle(dev);
+                __pm_runtime_idle(dev, 0);
 
         if (parent && !parent->power.ignore_children) {
                 spin_unlock_irq(&dev->power.lock);
@@ -329,13 +375,15 @@ EXPORT_SYMBOL_GPL(pm_runtime_suspend);
  * @dev: Device to resume.
  * @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,
- * either return imediately or wait for it to finish, depending on the
- * RPM_NOWAIT flag.  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, depending on the RPM_NOWAIT
- * flag.  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.
  */
@@ -348,28 +396,30 @@ static int __pm_runtime_resume(struct device *dev, int rpmflags)
         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;
-        }
 
+        /* Other scheduled or pending requests need to be canceled. */
         pm_runtime_cancel_pending(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 (rpmflags & RPM_NOWAIT) {
+                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 +441,17 @@ static int __pm_runtime_resume(struct device *dev, int rpmflags)
                 goto repeat;
         }
 
+        /* 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
@@ -460,7 +521,7 @@ static int __pm_runtime_resume(struct device *dev, int rpmflags)
         wake_up_all(&dev->power.wait_queue);
 
         if (!retval)
-                __pm_request_idle(dev);
+                __pm_runtime_idle(dev, RPM_ASYNC);
 
  out:
         if (parent) {
@@ -517,7 +578,7 @@ static void pm_runtime_work(struct work_struct *work)
         case RPM_REQ_NONE:
                 break;
         case RPM_REQ_IDLE:
-                __pm_runtime_idle(dev);
+                __pm_runtime_idle(dev, RPM_NOWAIT);
                 break;
         case RPM_REQ_SUSPEND:
                 __pm_runtime_suspend(dev, RPM_NOWAIT);
@@ -532,47 +593,6 @@ 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.
  */
@@ -582,7 +602,7 @@ int pm_request_idle(struct device *dev)
         int retval;
 
         spin_lock_irqsave(&dev->power.lock, flags);
-        retval = __pm_request_idle(dev);
+        retval = __pm_runtime_idle(dev, RPM_ASYNC);
         spin_unlock_irqrestore(&dev->power.lock, flags);
 
         return retval;
@@ -590,59 +610,10 @@ int pm_request_idle(struct device *dev)
 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 +627,7 @@ 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);
+                __pm_runtime_suspend(dev, RPM_ASYNC);
         }
 
         spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -670,47 +641,24 @@ 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 = __pm_runtime_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;
         mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
 
  out:
@@ -723,49 +671,6 @@ EXPORT_SYMBOL_GPL(pm_schedule_suspend);
 /**
  * pm_request_resume - Submit a resume request for given device.
  * @dev: Device to resume.
- *
- * This function must be called under dev->power.lock with interrupts disabled.
- */
-static int __pm_request_resume(struct device *dev)
-{
-        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);
-
-        if (dev->power.runtime_status == RPM_SUSPENDING) {
-                dev->power.deferred_resume = true;
-                return retval;
-        }
-        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);
-
-        return retval;
-}
-
-/**
- * pm_request_resume - Submit a resume request for given device.
- * @dev: Device to resume.
  */
 int pm_request_resume(struct device *dev)
 {
@@ -773,7 +678,7 @@ int pm_request_resume(struct device *dev)
         int retval;
 
         spin_lock_irqsave(&dev->power.lock, flags);
-        retval = __pm_request_resume(dev);
+        retval = __pm_runtime_resume(dev, RPM_ASYNC);
         spin_unlock_irqrestore(&dev->power.lock, flags);
 
         return retval;
@@ -1088,7 +993,7 @@ 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);
+                __pm_runtime_idle(dev, 0);
 
  out:
         spin_unlock_irq(&dev->power.lock);