Merge branch 'pm-runtime' into pm-for-linus

* pm-runtime:
  PM / Runtime: Use device PM QoS constraints (v2)

2 files changed, 144 insertions, 28 deletions

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 86de6c50fc4..03f4bd069ca 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -47,21 +47,29 @@ static DEFINE_MUTEX(dev_pm_qos_mtx);
 static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
 
 /**
- * dev_pm_qos_read_value - Get PM QoS constraint for a given device.
+ * __dev_pm_qos_read_value - Get PM QoS constraint for a given device.
+ * @dev: Device to get the PM QoS constraint value for.
+ *
+ * This routine must be called with dev->power.lock held.
+ */
+s32 __dev_pm_qos_read_value(struct device *dev)
+{
+	struct pm_qos_constraints *c = dev->power.constraints;
+
+	return c ? pm_qos_read_value(c) : 0;
+}
+
+/**
+ * dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked).
  * @dev: Device to get the PM QoS constraint value for.
  */
 s32 dev_pm_qos_read_value(struct device *dev)
 {
-	struct pm_qos_constraints *c;
 	unsigned long flags;
-	s32 ret = 0;
+	s32 ret;
 
 	spin_lock_irqsave(&dev->power.lock, flags);
-
-	c = dev->power.constraints;
-	if (c)
-		ret = pm_qos_read_value(c);
-
+	ret = __dev_pm_qos_read_value(dev);
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 
 	return ret;
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index c56efd75653..541f821d4ea 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -282,6 +282,47 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev)
 	return retval != -EACCES ? retval : -EIO;
 }
 
+struct rpm_qos_data {
+	ktime_t time_now;
+	s64 constraint_ns;
+};
+
+/**
+ * rpm_update_qos_constraint - Update a given PM QoS constraint data.
+ * @dev: Device whose timing data to use.
+ * @data: PM QoS constraint data to update.
+ *
+ * Use the suspend timing data of @dev to update PM QoS constraint data pointed
+ * to by @data.
+ */
+static int rpm_update_qos_constraint(struct device *dev, void *data)
+{
+	struct rpm_qos_data *qos = data;
+	unsigned long flags;
+	s64 delta_ns;
+	int ret = 0;
+
+	spin_lock_irqsave(&dev->power.lock, flags);
+
+	if (dev->power.max_time_suspended_ns < 0)
+		goto out;
+
+	delta_ns = dev->power.max_time_suspended_ns -
+		ktime_to_ns(ktime_sub(qos->time_now, dev->power.suspend_time));
+	if (delta_ns <= 0) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	if (qos->constraint_ns > delta_ns || qos->constraint_ns == 0)
+		qos->constraint_ns = delta_ns;
+
+ out:
+	spin_unlock_irqrestore(&dev->power.lock, flags);
+
+	return ret;
+}
+
 /**
  * rpm_suspend - Carry out runtime suspend of given device.
  * @dev: Device to suspend.
@@ -308,6 +349,7 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 {
 	int (*callback)(struct device *);
 	struct device *parent = NULL;
+	struct rpm_qos_data qos;
 	int retval;
 
 	trace_rpm_suspend(dev, rpmflags);
@@ -403,8 +445,38 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 		goto out;
 	}
 
+	qos.constraint_ns = __dev_pm_qos_read_value(dev);
+	if (qos.constraint_ns < 0) {
+		/* Negative constraint means "never suspend". */
+		retval = -EPERM;
+		goto out;
+	}
+	qos.constraint_ns *= NSEC_PER_USEC;
+	qos.time_now = ktime_get();
+
 	__update_runtime_status(dev, RPM_SUSPENDING);
 
+	if (!dev->power.ignore_children) {
+		if (dev->power.irq_safe)
+			spin_unlock(&dev->power.lock);
+		else
+			spin_unlock_irq(&dev->power.lock);
+
+		retval = device_for_each_child(dev, &qos,
+					       rpm_update_qos_constraint);
+
+		if (dev->power.irq_safe)
+			spin_lock(&dev->power.lock);
+		else
+			spin_lock_irq(&dev->power.lock);
+
+		if (retval)
+			goto fail;
+	}
+
+	dev->power.suspend_time = qos.time_now;
+	dev->power.max_time_suspended_ns = qos.constraint_ns ? : -1;
+
 	if (dev->pm_domain)
 		callback = dev->pm_domain->ops.runtime_suspend;
 	else if (dev->type && dev->type->pm)
@@ -420,27 +492,9 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 		callback = dev->driver->pm->runtime_suspend;
 
 	retval = rpm_callback(callback, dev);
-	if (retval) {
-		__update_runtime_status(dev, RPM_ACTIVE);
-		dev->power.deferred_resume = false;
-		if (retval == -EAGAIN || retval == -EBUSY) {
-			dev->power.runtime_error = 0;
+	if (retval)
+		goto fail;
 
-			/*
-			 * If the callback routine failed an autosuspend, and
-			 * if the last_busy time has been updated so that there
-			 * is a new autosuspend expiration time, automatically
-			 * reschedule another autosuspend.
-			 */
-			if ((rpmflags & RPM_AUTO) &&
-			    pm_runtime_autosuspend_expiration(dev) != 0)
-				goto repeat;
-		} else {
-			pm_runtime_cancel_pending(dev);
-		}
-		wake_up_all(&dev->power.wait_queue);
-		goto out;
-	}
  no_callback:
 	__update_runtime_status(dev, RPM_SUSPENDED);
 	pm_runtime_deactivate_timer(dev);
@@ -472,6 +526,29 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 	trace_rpm_return_int(dev, _THIS_IP_, retval);
 
 	return retval;
+
+ fail:
+	__update_runtime_status(dev, RPM_ACTIVE);
+	dev->power.suspend_time = ktime_set(0, 0);
+	dev->power.max_time_suspended_ns = -1;
+	dev->power.deferred_resume = false;
+	if (retval == -EAGAIN || retval == -EBUSY) {
+		dev->power.runtime_error = 0;
+
+		/*
+		 * If the callback routine failed an autosuspend, and
+		 * if the last_busy time has been updated so that there
+		 * is a new autosuspend expiration time, automatically
+		 * reschedule another autosuspend.
+		 */
+		if ((rpmflags & RPM_AUTO) &&
+		    pm_runtime_autosuspend_expiration(dev) != 0)
+			goto repeat;
+	} else {
+		pm_runtime_cancel_pending(dev);
+	}
+	wake_up_all(&dev->power.wait_queue);
+	goto out;
 }
 
 /**
@@ -626,6 +703,9 @@ static int rpm_resume(struct device *dev, int rpmflags)
 	if (dev->power.no_callbacks)
 		goto no_callback;	/* Assume success. */
 
+	dev->power.suspend_time = ktime_set(0, 0);
+	dev->power.max_time_suspended_ns = -1;
+
 	__update_runtime_status(dev, RPM_RESUMING);
 
 	if (dev->pm_domain)
@@ -1288,6 +1368,9 @@ void pm_runtime_init(struct device *dev)
 	setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
 			(unsigned long)dev);
 
+	dev->power.suspend_time = ktime_set(0, 0);
+	dev->power.max_time_suspended_ns = -1;
+
 	init_waitqueue_head(&dev->power.wait_queue);
 }
 
@@ -1305,3 +1388,28 @@ void pm_runtime_remove(struct device *dev)
 	if (dev->power.irq_safe && dev->parent)
 		pm_runtime_put_sync(dev->parent);
 }
+
+/**
+ * pm_runtime_update_max_time_suspended - Update device's suspend time data.
+ * @dev: Device to handle.
+ * @delta_ns: Value to subtract from the device's max_time_suspended_ns field.
+ *
+ * Update the device's power.max_time_suspended_ns field by subtracting
+ * @delta_ns from it.  The resulting value of power.max_time_suspended_ns is
+ * never negative.
+ */
+void pm_runtime_update_max_time_suspended(struct device *dev, s64 delta_ns)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->power.lock, flags);
+
+	if (delta_ns > 0 && dev->power.max_time_suspended_ns > 0) {
+		if (dev->power.max_time_suspended_ns > delta_ns)
+			dev->power.max_time_suspended_ns -= delta_ns;
+		else
+			dev->power.max_time_suspended_ns = 0;
+	}
+
+	spin_unlock_irqrestore(&dev->power.lock, flags);
+}