1 files changed, 142 insertions, 21 deletions

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index a5142bddef4..d477f4dc5e5 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -25,6 +25,7 @@
 #include <linux/resume-trace.h>
 #include <linux/interrupt.h>
 #include <linux/sched.h>
+#include <linux/async.h>
 
 #include "../base.h"
 #include "power.h"
@@ -34,14 +35,15 @@
  * because children are guaranteed to be discovered after parents, and
  * are inserted at the back of the list on discovery.
  *
- * Since device_pm_add() may be called with a device semaphore held,
- * we must never try to acquire a device semaphore while holding
+ * Since device_pm_add() may be called with a device lock held,
+ * we must never try to acquire a device lock while holding
  * dpm_list_mutex.
  */
 
 LIST_HEAD(dpm_list);
 
 static DEFINE_MUTEX(dpm_list_mtx);
+static pm_message_t pm_transition;
 
 /*
  * Set once the preparation of devices for a PM transition has started, reset
@@ -56,6 +58,7 @@ static bool transition_started;
 void device_pm_init(struct device *dev)
 {
 	dev->power.status = DPM_ON;
+	init_completion(&dev->power.completion);
 	pm_runtime_init(dev);
 }
 
@@ -111,6 +114,7 @@ void device_pm_remove(struct device *dev)
 	pr_debug("PM: Removing info for %s:%s\n",
 		 dev->bus ? dev->bus->name : "No Bus",
 		 kobject_name(&dev->kobj));
+	complete_all(&dev->power.completion);
 	mutex_lock(&dpm_list_mtx);
 	list_del_init(&dev->power.entry);
 	mutex_unlock(&dpm_list_mtx);
@@ -188,6 +192,31 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime,
 }
 
 /**
+ * dpm_wait - Wait for a PM operation to complete.
+ * @dev: Device to wait for.
+ * @async: If unset, wait only if the device's power.async_suspend flag is set.
+ */
+static void dpm_wait(struct device *dev, bool async)
+{
+	if (!dev)
+		return;
+
+	if (async || (pm_async_enabled && dev->power.async_suspend))
+		wait_for_completion(&dev->power.completion);
+}
+
+static int dpm_wait_fn(struct device *dev, void *async_ptr)
+{
+	dpm_wait(dev, *((bool *)async_ptr));
+	return 0;
+}
+
+static void dpm_wait_for_children(struct device *dev, bool async)
+{
+       device_for_each_child(dev, &async, dpm_wait_fn);
+}
+
+/**
  * pm_op - Execute the PM operation appropriate for given PM event.
  * @dev: Device to handle.
  * @ops: PM operations to choose from.
@@ -271,8 +300,9 @@ static int pm_noirq_op(struct device *dev,
 	ktime_t calltime, delta, rettime;
 
 	if (initcall_debug) {
-		pr_info("calling  %s_i+ @ %i\n",
-				dev_name(dev), task_pid_nr(current));
+		pr_info("calling  %s+ @ %i, parent: %s\n",
+				dev_name(dev), task_pid_nr(current),
+				dev->parent ? dev_name(dev->parent) : "none");
 		calltime = ktime_get();
 	}
 
@@ -468,15 +498,19 @@ static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
  * device_resume - Execute "resume" callbacks for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
+ * @async: If true, the device is being resumed asynchronously.
  */
-static int device_resume(struct device *dev, pm_message_t state)
+static int device_resume(struct device *dev, pm_message_t state, bool async)
 {
 	int error = 0;
 
 	TRACE_DEVICE(dev);
 	TRACE_RESUME(0);
 
-	down(&dev->sem);
+	dpm_wait(dev->parent, async);
+	device_lock(dev);
+
+	dev->power.status = DPM_RESUMING;
 
 	if (dev->bus) {
 		if (dev->bus->pm) {
@@ -509,12 +543,30 @@ static int device_resume(struct device *dev, pm_message_t state)
 		}
 	}
  End:
-	up(&dev->sem);
+	device_unlock(dev);
+	complete_all(&dev->power.completion);
 
 	TRACE_RESUME(error);
 	return error;
 }
 
+static void async_resume(void *data, async_cookie_t cookie)
+{
+	struct device *dev = (struct device *)data;
+	int error;
+
+	error = device_resume(dev, pm_transition, true);
+	if (error)
+		pm_dev_err(dev, pm_transition, " async", error);
+	put_device(dev);
+}
+
+static bool is_async(struct device *dev)
+{
+	return dev->power.async_suspend && pm_async_enabled
+		&& !pm_trace_is_enabled();
+}
+
 /**
  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
  * @state: PM transition of the system being carried out.
@@ -525,21 +577,33 @@ static int device_resume(struct device *dev, pm_message_t state)
 static void dpm_resume(pm_message_t state)
 {
 	struct list_head list;
+	struct device *dev;
 	ktime_t starttime = ktime_get();
 
 	INIT_LIST_HEAD(&list);
 	mutex_lock(&dpm_list_mtx);
-	while (!list_empty(&dpm_list)) {
-		struct device *dev = to_device(dpm_list.next);
+	pm_transition = state;
+
+	list_for_each_entry(dev, &dpm_list, power.entry) {
+		if (dev->power.status < DPM_OFF)
+			continue;
+
+		INIT_COMPLETION(dev->power.completion);
+		if (is_async(dev)) {
+			get_device(dev);
+			async_schedule(async_resume, dev);
+		}
+	}
 
+	while (!list_empty(&dpm_list)) {
+		dev = to_device(dpm_list.next);
 		get_device(dev);
-		if (dev->power.status >= DPM_OFF) {
+		if (dev->power.status >= DPM_OFF && !is_async(dev)) {
 			int error;
 
-			dev->power.status = DPM_RESUMING;
 			mutex_unlock(&dpm_list_mtx);
 
-			error = device_resume(dev, state);
+			error = device_resume(dev, state, false);
 
 			mutex_lock(&dpm_list_mtx);
 			if (error)
@@ -554,6 +618,7 @@ static void dpm_resume(pm_message_t state)
 	}
 	list_splice(&list, &dpm_list);
 	mutex_unlock(&dpm_list_mtx);
+	async_synchronize_full();
 	dpm_show_time(starttime, state, NULL);
 }
 
@@ -564,7 +629,7 @@ static void dpm_resume(pm_message_t state)
  */
 static void device_complete(struct device *dev, pm_message_t state)
 {
-	down(&dev->sem);
+	device_lock(dev);
 
 	if (dev->class && dev->class->pm && dev->class->pm->complete) {
 		pm_dev_dbg(dev, state, "completing class ");
@@ -581,7 +646,7 @@ static void device_complete(struct device *dev, pm_message_t state)
 		dev->bus->pm->complete(dev);
 	}
 
-	up(&dev->sem);
+	device_unlock(dev);
 }
 
 /**
@@ -731,16 +796,23 @@ static int legacy_suspend(struct device *dev, pm_message_t state,
 	return error;
 }
 
+static int async_error;
+
 /**
  * device_suspend - Execute "suspend" callbacks for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
+ * @async: If true, the device is being suspended asynchronously.
  */
-static int device_suspend(struct device *dev, pm_message_t state)
+static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 {
 	int error = 0;
 
-	down(&dev->sem);
+	dpm_wait_for_children(dev, async);
+	device_lock(dev);
+
+	if (async_error)
+		goto End;
 
 	if (dev->class) {
 		if (dev->class->pm) {
@@ -772,12 +844,44 @@ static int device_suspend(struct device *dev, pm_message_t state)
 			error = legacy_suspend(dev, state, dev->bus->suspend);
 		}
 	}
+
+	if (!error)
+		dev->power.status = DPM_OFF;
+
  End:
-	up(&dev->sem);
+	device_unlock(dev);
+	complete_all(&dev->power.completion);
 
 	return error;
 }
 
+static void async_suspend(void *data, async_cookie_t cookie)
+{
+	struct device *dev = (struct device *)data;
+	int error;
+
+	error = __device_suspend(dev, pm_transition, true);
+	if (error) {
+		pm_dev_err(dev, pm_transition, " async", error);
+		async_error = error;
+	}
+
+	put_device(dev);
+}
+
+static int device_suspend(struct device *dev)
+{
+	INIT_COMPLETION(dev->power.completion);
+
+	if (pm_async_enabled && dev->power.async_suspend) {
+		get_device(dev);
+		async_schedule(async_suspend, dev);
+		return 0;
+	}
+
+	return __device_suspend(dev, pm_transition, false);
+}
+
 /**
  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
  * @state: PM transition of the system being carried out.
@@ -790,13 +894,15 @@ static int dpm_suspend(pm_message_t state)
 
 	INIT_LIST_HEAD(&list);
 	mutex_lock(&dpm_list_mtx);
+	pm_transition = state;
+	async_error = 0;
 	while (!list_empty(&dpm_list)) {
 		struct device *dev = to_device(dpm_list.prev);
 
 		get_device(dev);
 		mutex_unlock(&dpm_list_mtx);
 
-		error = device_suspend(dev, state);
+		error = device_suspend(dev);
 
 		mutex_lock(&dpm_list_mtx);
 		if (error) {
@@ -804,13 +910,17 @@ static int dpm_suspend(pm_message_t state)
 			put_device(dev);
 			break;
 		}
-		dev->power.status = DPM_OFF;
 		if (!list_empty(&dev->power.entry))
 			list_move(&dev->power.entry, &list);
 		put_device(dev);
+		if (async_error)
+			break;
 	}
 	list_splice(&list, dpm_list.prev);
 	mutex_unlock(&dpm_list_mtx);
+	async_synchronize_full();
+	if (!error)
+		error = async_error;
 	if (!error)
 		dpm_show_time(starttime, state, NULL);
 	return error;
@@ -828,7 +938,7 @@ static int device_prepare(struct device *dev, pm_message_t state)
 {
 	int error = 0;
 
-	down(&dev->sem);
+	device_lock(dev);
 
 	if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) {
 		pm_dev_dbg(dev, state, "preparing ");
@@ -852,7 +962,7 @@ static int device_prepare(struct device *dev, pm_message_t state)
 		suspend_report_result(dev->class->pm->prepare, error);
 	}
  End:
-	up(&dev->sem);
+	device_unlock(dev);
 
 	return error;
 }
@@ -936,3 +1046,14 @@ void __suspend_report_result(const char *function, void *fn, int ret)
 		printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
 }
 EXPORT_SYMBOL_GPL(__suspend_report_result);
+
+/**
+ * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
+ * @dev: Device to wait for.
+ * @subordinate: Device that needs to wait for @dev.
+ */
+void device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
+{
+	dpm_wait(dev, subordinate->power.async_suspend);
+}
+EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);