diff mbox

Async resume patch (was: Re: [GIT PULL] PM updates for 2.6.33)

Message ID 200912081323.50606.rjw@sisk.pl (mailing list archive)
State RFC, archived
Headers show

Commit Message

Rafael Wysocki Dec. 8, 2009, 12:23 p.m. UTC
None
diff mbox

Patch

Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -412,15 +412,17 @@  struct dev_pm_info {
 	pm_message_t		power_state;
 	unsigned int		can_wakeup:1;
 	unsigned int		should_wakeup:1;
+	unsigned		async_suspend:1;
 	enum dpm_state		status;		/* Owned by the PM core */
+	wait_queue_head_t	wait_queue;
 #ifdef CONFIG_PM_SLEEP
 	struct list_head	entry;
+	unsigned int            op_complete:1;
 #endif
 #ifdef CONFIG_PM_RUNTIME
 	struct timer_list	suspend_timer;
 	unsigned long		timer_expires;
 	struct work_struct	work;
-	wait_queue_head_t	wait_queue;
 	spinlock_t		lock;
 	atomic_t		usage_count;
 	atomic_t		child_count;
Index: linux-2.6/include/linux/device.h
===================================================================
--- linux-2.6.orig/include/linux/device.h
+++ linux-2.6/include/linux/device.h
@@ -472,6 +472,12 @@  static inline int device_is_registered(s
 	return dev->kobj.state_in_sysfs;
 }
 
+static inline void device_enable_async_suspend(struct device *dev, bool enable)
+{
+	if (dev->power.status == DPM_ON)
+		dev->power.async_suspend = enable;
+}
+
 void driver_init(void);
 
 /*
Index: linux-2.6/drivers/base/power/main.c
===================================================================
--- linux-2.6.orig/drivers/base/power/main.c
+++ linux-2.6/drivers/base/power/main.c
@@ -25,6 +25,7 @@ 
 #include <linux/resume-trace.h>
 #include <linux/rwsem.h>
 #include <linux/interrupt.h>
+#include <linux/async.h>
 
 #include "../base.h"
 #include "power.h"
@@ -42,6 +43,7 @@ 
 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_waitqueue_head(&dev->power.wait_queue);
 	pm_runtime_init(dev);
 }
 
@@ -162,6 +165,56 @@  void device_pm_move_last(struct device *
 }
 
 /**
+ * dpm_reset - Clear op_complete for given device.
+ * @dev: Device to handle.
+ */
+static void dpm_reset(struct device *dev)
+{
+       dev->power.op_complete = false;
+}
+
+/**
+ * dpm_finish - Set op_complete for a device and wake up threads waiting for it.
+ */
+static void dpm_finish(struct device *dev)
+{
+	dev->power.op_complete = true;
+	wake_up_all(&dev->power.wait_queue);
+}
+
+/**
+ * dpm_wait - Wait for a PM operation to complete.
+ * @dev: Device to wait for.
+ * @async: If true, ignore the device's async_suspend flag.
+ *
+ * Wait for a PM operation carried out for @dev to complete, unless @dev has to
+ * be handled synchronously and @async is false.
+ */
+static void dpm_wait(struct device *dev, bool async)
+{
+       if (!dev)
+               return;
+
+       if (!(async || dev->power.async_suspend))
+               return;
+
+       if (!dev->power.op_complete)
+               wait_event(dev->power.wait_queue, !!dev->power.op_complete);
+}
+
+/**
+ * dpm_synchronize - Wait for PM callbacks of all devices to complete.
+ */
+static void dpm_synchronize(void)
+{
+	struct device *dev;
+
+	async_synchronize_full();
+	list_for_each_entry(dev, &dpm_list, power.entry)
+		dpm_reset(dev);
+}
+
+/**
  * pm_op - Execute the PM operation appropriate for given PM event.
  * @dev: Device to handle.
  * @ops: PM operations to choose from.
@@ -334,25 +387,48 @@  static void pm_dev_err(struct device *de
  * The driver of @dev will not receive interrupts while this function is being
  * executed.
  */
-static int device_resume_noirq(struct device *dev, pm_message_t state)
+static int __device_resume_noirq(struct device *dev, pm_message_t state)
 {
 	int error = 0;
 
 	TRACE_DEVICE(dev);
 	TRACE_RESUME(0);
 
-	if (!dev->bus)
-		goto End;
-
-	if (dev->bus->pm) {
+	if (dev->bus && dev->bus->pm) {
 		pm_dev_dbg(dev, state, "EARLY ");
 		error = pm_noirq_op(dev, dev->bus->pm, state);
 	}
- End:
+
+	dpm_finish(dev);
+
 	TRACE_RESUME(error);
 	return error;
 }
 
+static void async_resume_noirq(void *data, async_cookie_t cookie)
+{
+	struct device *dev = (struct device *)data;
+	int error;
+
+	dpm_wait(dev->parent, true);
+	error = __device_resume_noirq(dev, pm_transition);
+	if (error)
+		pm_dev_err(dev, pm_transition, " async EARLY", error);
+	put_device(dev);
+}
+
+static int device_resume_noirq(struct device *dev)
+{
+	if (dev->power.async_suspend && !pm_trace_is_enabled()) {
+		get_device(dev);
+		async_schedule(async_resume_noirq, dev);
+		return 0;
+	}
+
+	dpm_wait(dev->parent, false);
+	return __device_resume_noirq(dev, pm_transition);
+}
+
 /**
  * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
  * @state: PM transition of the system being carried out.
@@ -366,26 +442,28 @@  void dpm_resume_noirq(pm_message_t state
 
 	mutex_lock(&dpm_list_mtx);
 	transition_started = false;
+	pm_transition = state;
 	list_for_each_entry(dev, &dpm_list, power.entry)
 		if (dev->power.status > DPM_OFF) {
 			int error;
 
 			dev->power.status = DPM_OFF;
-			error = device_resume_noirq(dev, state);
+			error = device_resume_noirq(dev);
 			if (error)
 				pm_dev_err(dev, state, " early", error);
 		}
+	dpm_synchronize();
 	mutex_unlock(&dpm_list_mtx);
 	resume_device_irqs();
 }
 EXPORT_SYMBOL_GPL(dpm_resume_noirq);
 
 /**
- * device_resume - Execute "resume" callbacks for given device.
+ * __device_resume - Execute "resume" callbacks for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
  */
-static int device_resume(struct device *dev, pm_message_t state)
+static int __device_resume(struct device *dev, pm_message_t state)
 {
 	int error = 0;
 
@@ -426,11 +504,36 @@  static int device_resume(struct device *
 	}
  End:
 	up(&dev->sem);
+	dpm_finish(dev);
 
 	TRACE_RESUME(error);
 	return error;
 }
 
+static void async_resume(void *data, async_cookie_t cookie)
+{
+	struct device *dev = (struct device *)data;
+	int error;
+
+	dpm_wait(dev->parent, true);
+	error = __device_resume(dev, pm_transition);
+	if (error)
+		pm_dev_err(dev, pm_transition, " async", error);
+	put_device(dev);
+}
+
+static int device_resume(struct device *dev)
+{
+	if (dev->power.async_suspend && !pm_trace_is_enabled()) {
+		get_device(dev);
+		async_schedule(async_resume, dev);
+		return 0;
+	}
+
+	dpm_wait(dev->parent, false);
+	return __device_resume(dev, pm_transition);
+}
+
 /**
  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
  * @state: PM transition of the system being carried out.
@@ -444,6 +547,7 @@  static void dpm_resume(pm_message_t stat
 
 	INIT_LIST_HEAD(&list);
 	mutex_lock(&dpm_list_mtx);
+	pm_transition = state;
 	while (!list_empty(&dpm_list)) {
 		struct device *dev = to_device(dpm_list.next);
 
@@ -454,7 +558,7 @@  static void dpm_resume(pm_message_t stat
 			dev->power.status = DPM_RESUMING;
 			mutex_unlock(&dpm_list_mtx);
 
-			error = device_resume(dev, state);
+			error = device_resume(dev);
 
 			mutex_lock(&dpm_list_mtx);
 			if (error)
@@ -468,6 +572,7 @@  static void dpm_resume(pm_message_t stat
 		put_device(dev);
 	}
 	list_splice(&list, &dpm_list);
+	dpm_synchronize();
 	mutex_unlock(&dpm_list_mtx);
 }
 
@@ -793,8 +898,10 @@  static int dpm_prepare(pm_message_t stat
 			break;
 		}
 		dev->power.status = DPM_SUSPENDING;
-		if (!list_empty(&dev->power.entry))
+		if (!list_empty(&dev->power.entry)) {
 			list_move_tail(&dev->power.entry, &list);
+			dpm_reset(dev);
+		}
 		put_device(dev);
 	}
 	list_splice(&list, &dpm_list);
Index: linux-2.6/include/linux/resume-trace.h
===================================================================
--- linux-2.6.orig/include/linux/resume-trace.h
+++ linux-2.6/include/linux/resume-trace.h
@@ -6,6 +6,11 @@ 
 
 extern int pm_trace_enabled;
 
+static inline int pm_trace_is_enabled(void)
+{
+       return pm_trace_enabled;
+}
+
 struct device;
 extern void set_trace_device(struct device *);
 extern void generate_resume_trace(const void *tracedata, unsigned int user);
@@ -17,6 +22,8 @@  extern void generate_resume_trace(const 
 
 #else
 
+static inline int pm_trace_is_enabled(void) { return 0; }
+
 #define TRACE_DEVICE(dev) do { } while (0)
 #define TRACE_RESUME(dev) do { } while (0)