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 86de6c50fc41..03f4bd069ca8 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 c56efd756531..541f821d4ea6 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);
+}