[RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks

[RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Introduce 'struct pm_ops' representing a set of suspend and
hibernation operations for bus types, device classes and device
types.

Modify the PM core to use 'struct pm_ops' objects, if defined, instead
of the ->suspend(), ->resume(), ->suspend_late(), ->resume_early()
callbacks that will be considered as legacy and gradually phased out.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---

 arch/x86/kernel/apm_32.c  |    4 
 drivers/base/power/main.c |  453 +++++++++++++++++++++++++++++++++++-----------
 include/linux/device.h    |    8 
 include/linux/pm.h        |  241 +++++++++++++++++++++---
 kernel/power/disk.c       |   14 -
 kernel/power/main.c       |    4 
 6 files changed, 583 insertions(+), 141 deletions(-)

Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -114,7 +114,9 @@ typedef struct pm_message {
 	int event;
 } pm_message_t;
 
-/*
+/**
+ * struct pm_ops - device PM callbacks
+ *
  * Several driver power state transitions are externally visible, affecting
  * the state of pending I/O queues and (for drivers that touch hardware)
  * interrupts, wakeups, DMA, and other hardware state.  There may also be
@@ -122,6 +124,213 @@ typedef struct pm_message {
  * to the rest of the driver stack (such as a driver that's ON gating off
  * clocks which are not in active use).
  *
+ * The externally visible transitions are handled with the help of the following
+ * callbacks included in this structure:
+ *
+ * @prepare: Prepare the device for the upcoming transition, but do NOT change
+ *	its hardware state.  Prevent new children of the device from being
+ *	registered and prevent new calls to the probe method from being made
+ *	after @prepare() returns.  Also, if a concurrent child registration
+ *	or a call to the probe method already in progress is detected by
+ *	@prepare(), it may return -EAGAIN, so that the PM core can execute it
+ *	once again (e.g. after suspending the newly registered child) to recover
+ *	from the race condition. This method is executed for all kinds of
+ *	suspend transitions and is immediately followed by one of the suspend
+ *	callbacks: @suspend(), @freeze(), @poweroff(), or @quiesce().
+ *
+ * @complete: Undo the changes made by @prepare().  This method is executed for
+ *	all kinds of resume transitions, immediately following one of the resume
+ *	callbacks: @resume(), @thaw(), @restore(), or @recover().  Also executed
+ *	if a suspend callback (@suspend(), @freeze(), @poweroff(), @quiesce())
+ *	immediately following a successful @prepare() fails OR if a new child
+ *	of the device has been registered during @prepare().
+ *
+ * @suspend: Executed before putting the system into a sleep state in which the
+ *	contents of main memory are preserved.  Quiesce the device, put it into
+ *	a low power state appropriate for the upcoming system state (such as
+ *	PCI_D3hot), and enable wakeup events as appropriate.
+ *
+ * @resume: Executed after waking the system up from a sleep state in which the
+ *	contents of main memory were preserved.  Put the device into the
+ *	appropriate state, according to the information saved in memory by the
+ *	preceding @suspend().  The driver starts working again, responding to
+ *	hardware events and software requests.  The hardware may have gone
+ *	through a power-off reset, or it may have maintained state from the
+ *	previous suspend() which the driver may rely on while resuming.  On most
+ *	platforms, there are no restrictions on availability of resources like
+ *	clocks during @resume().
+ *
+ * @freeze: Hibernation-specific, executed before creating a hibernation image.
+ *	Quiesce operations so that a consistent image can be created, but do NOT
+ *	otherwise put the device into a low power device state and do NOT emit
+ *	system wakeup events.  Save in main memory the device settings to be
+ *	used by @restore() during the subsequent resume from hibernation.
+ *
+ * @thaw: Hibernation-specific, executed after creating a hibernation image.
+ *	Undo the changes made by the preceding @freeze(), so the device can be
+ *	operated in the same way as immediately before the call to @freeze().
+ *
+ * @poweroff: Hibernation-specific, executed after saving a hibernation image.
+ *	Quiesce the device, put it into a low power state appropriate for the
+ *	upcoming system state (such as PCI_D3hot), and enable wakeup events as
+ *	appropriate.
+ *
+ * @quiesce: Hibernation-specific, executed after loading a hibernation image
+ *	and before restoring the contents of main memory from it.  Quiesce
+ *	operations so that the contents of main memory can be restored from the
+ *	image in a consistent way, but do NOT otherwise put the device into a
+ *	low power state and do NOT emit system wakeup events.  Do NOT save any
+ *	device settings in main memory.
+ *
+ * @restore: Hibernation-specific, executed after restoring the contents of main
+ *	memory from a hibernation image.  Driver starts working again,
+ *	responding to hardware events and software requests.  Do NOT make ANY
+ *	assumptions about the hardware state right prior to @restore().  On most
+ *	platforms, there are no restrictions on availability of resources like
+ *	clocks during @restore().
+ *
+ * @recover: Hibernation-specific, executed after a failing creation of a
+ *	hibernation image OR after a failing attempt to restore the contents of
+ *	main memory from such an image.  Undo the changes made by the preceding
+ *	@freeze() or @quiesce(), so the device can be operated in the same way
+ *	as immediately before the failing transition.
+ *
+ * struct pm_ops is also used for defining driver PM operations to be carried
+ * out with interrupts disabled.  In this case, however, there is only one
+ * active CPU while the operations are being performed, so they are executed by
+ * the PM core in a more straightforward way.  In particular, the failure of
+ * @prepare() carried out with interrupts disabled causes the entire PM
+ * transition to fail, regardless of the error code returned by it.
+ *
+ * All of the above callbacks, except for @complete(), return error codes.
+ * However, the error codes returned by resume operations, @resume(), @thaw(),
+ * @restore(), and @recover(), are only printed in the system logs, since the
+ * PM core cannot do anything else about them.
+ */
+
+struct pm_ops {
+#ifdef CONFIG_PM_SLEEP
+	int (*prepare)(struct device *dev);
+	void (*complete)(struct device *dev);
+#endif
+#ifdef CONFIG_SUSPEND
+	int (*suspend)(struct device *dev);
+	int (*resume)(struct device *dev);
+#endif
+#ifdef CONFIG_HIBERNATION
+	int (*freeze)(struct device *dev);
+	int (*thaw)(struct device *dev);
+	int (*poweroff)(struct device *dev);
+	int (*quiesce)(struct device *dev);
+	int (*restore)(struct device *dev);
+	int (*recover)(struct device *dev);
+#endif
+};
+
+/**
+ * PM_EVENT_ messages
+ *
+ * The following PM_EVENT_ messages are defined for the internal use of the PM
+ * core, in order to provide a mechanism allowing the high level suspend and
+ * hibernation code to convey the necessary information to the device PM core
+ * code:
+ *
+ * ON		No transition.
+ *
+ * FREEZE 	System is going to hibernate, call ->prepare() and ->freeze()
+ *		for all devices.
+ *
+ * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
+ *		for all devices.
+ *
+ * HIBERNATE	Hibernation image has been saved, call ->prepare() and
+ *		->poweroff() for all devices.
+ *
+ * QUIESCE	Contents of main memory are going to be restored from a (loaded)
+ *		hibernation image, call ->prepare() and ->quiesce() for all
+ *		devices.
+ *
+ * RESUME	System is resuming, call ->resume() and ->complete() for all
+ *		devices.
+ *
+ * THAW		Hibernation image has been created, call ->thaw() and
+ *		->complete() for all devices.
+ *
+ * RESTORE	Contents of main memory have been restored from a hibernation
+ *		image, call ->restore() and ->complete() for all devices.
+ *
+ * RECOVER	Creation of a hibernation image or restoration of the main
+ *		memory contents from a hibernation image has failed, call
+ *		->recover() and ->complete() for all devices.
+ */
+
+#define PM_EVENT_ON		0x0000
+#define PM_EVENT_FREEZE 	0x0001
+#define PM_EVENT_SUSPEND	0x0002
+#define PM_EVENT_HIBERNATE	0x0004
+#define PM_EVENT_QUIESCE	0x0008
+#define PM_EVENT_RESUME		0x0010
+#define PM_EVENT_THAW		0x0020
+#define PM_EVENT_RESTORE	0x0040
+#define PM_EVENT_RECOVER	0x0080
+
+#define PM_EVENT_SLEEP	(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
+
+#define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
+#define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
+#define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
+#define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
+#define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
+#define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
+#define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
+#define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
+#define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
+
+/**
+ * Device power management states
+ *
+ * These state labels are used internally by the PM core to indicate the current
+ * status of a device with respect to the PM core operations.
+ *
+ * DPM_ON		Device is regarded as operational.  Set this way
+ *			initially and when ->resume(), ->thaw(), ->restore(),
+ *			->recover(), or ->complete() is about to be called.
+ *			Also set when ->prepare() fails.
+ *
+ * DPM_SUSPENDING	Device is currently being suspended.  Set when
+ *			->prepare() is about to be called.
+ *
+ * DPM_OFF		Device is regarded as suspended.  Set when ->suspend(),
+ *			->freeze(), ->poweroff(), or ->quiesce() is about to be
+ *			called.
+ */
+
+enum dpm_state {
+	DPM_ON,
+	DPM_SUSPENDING,
+	DPM_OFF,
+};
+
+struct dev_pm_info {
+	pm_message_t		power_state;
+	unsigned		can_wakeup:1;
+	unsigned		should_wakeup:1;
+	enum dpm_state		status:2;	/* Owned by the PM core */
+#ifdef	CONFIG_PM_SLEEP
+	struct list_head	entry;
+#endif
+};
+
+/*
+ * The PM_EVENT_ messages are also used by drivers implementing the legacy
+ * suspend framework, based on the ->suspend() and ->resume() callbacks common
+ * for suspend and hibernation transitions, according to the rules below.
+ */
+
+/* Necessary, because several drivers use PM_EVENT_PRETHAW */
+#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
+
+/*
  * One transition is triggered by resume(), after a suspend() call; the
  * message is implicit:
  *
@@ -166,35 +375,11 @@ typedef struct pm_message {
  * or from system low-power states such as standby or suspend-to-RAM.
  */
 
-#define PM_EVENT_ON 0
-#define PM_EVENT_FREEZE 1
-#define PM_EVENT_SUSPEND 2
-#define PM_EVENT_HIBERNATE 4
-#define PM_EVENT_PRETHAW 8
-
-#define PM_EVENT_SLEEP	(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
-
-#define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
-#define PMSG_PRETHAW	((struct pm_message){ .event = PM_EVENT_PRETHAW, })
-#define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
-#define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
-#define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
-
-struct dev_pm_info {
-	pm_message_t		power_state;
-	unsigned		can_wakeup:1;
-	unsigned		should_wakeup:1;
-	bool			sleeping:1;	/* Owned by the PM core */
-#ifdef	CONFIG_PM_SLEEP
-	struct list_head	entry;
-#endif
-};
+#ifdef CONFIG_PM_SLEEP
+extern void device_power_up(pm_message_t state);
+extern void device_resume(pm_message_t state);
 
 extern int device_power_down(pm_message_t state);
-extern void device_power_up(void);
-extern void device_resume(void);
-
-#ifdef CONFIG_PM_SLEEP
 extern int device_suspend(pm_message_t state);
 extern int device_prepare_suspend(pm_message_t state);
 
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
@@ -69,22 +69,30 @@ int device_pm_add(struct device *dev)
 		 dev->bus ? dev->bus->name : "No Bus",
 		 kobject_name(&dev->kobj));
 	mutex_lock(&dpm_list_mtx);
-	if ((dev->parent && dev->parent->power.sleeping) || all_sleeping) {
-		if (dev->parent->power.sleeping)
-			dev_warn(dev,
-				"parent %s is sleeping, will not add\n",
+	if (all_sleeping) {
+		dev_warn(dev, "all devices are sleeping, will not add\n");
+		goto Refuse;
+	}
+	if (dev->parent)
+		switch (dev->parent->power.status) {
+		case DPM_OFF:
+			dev_warn(dev, "parent %s is sleeping, will not add\n",
 				dev->parent->bus_id);
-		else
-			dev_warn(dev, "devices are sleeping, will not add\n");
-		WARN_ON(true);
-		error = -EBUSY;
-	} else {
-		error = dpm_sysfs_add(dev);
-		if (!error)
-			list_add_tail(&dev->power.entry, &dpm_active);
-	}
+			goto Refuse;
+		case DPM_SUSPENDING:
+			dev->parent->power.status = DPM_ON;
+			break;
+		}
+	error = dpm_sysfs_add(dev);
+	if (!error)
+		list_add_tail(&dev->power.entry, &dpm_active);
+ End:
 	mutex_unlock(&dpm_list_mtx);
 	return error;
+ Refuse:
+	WARN_ON(true);
+	error = -EBUSY;
+	goto End;
 }
 
 /**
@@ -122,26 +130,135 @@ void device_pm_schedule_removal(struct d
 }
 EXPORT_SYMBOL_GPL(device_pm_schedule_removal);
 
+/**
+ *	pm_op - execute the PM operation appropiate for given PM event
+ *	@dev:	Device.
+ *	@ops:	PM operations to choose from.
+ *	@state:	PM event message.
+ */
+static int pm_op(struct device *dev, struct pm_ops *ops, pm_message_t state)
+{
+	int error = 0;
+
+	switch (state.event) {
+#ifdef CONFIG_SUSPEND
+	case PM_EVENT_SUSPEND:
+		if (ops->suspend) {
+			error = ops->suspend(dev);
+			suspend_report_result(ops->suspend, error);
+		}
+		break;
+	case PM_EVENT_RESUME:
+		if (ops->resume) {
+			error = ops->resume(dev);
+			suspend_report_result(ops->resume, error);
+		}
+		break;
+#endif /* CONFIG_SUSPEND */
+#ifdef CONFIG_HIBERNATION
+	case PM_EVENT_FREEZE:
+		if (ops->freeze) {
+			error = ops->freeze(dev);
+			suspend_report_result(ops->freeze, error);
+		}
+		break;
+	case PM_EVENT_QUIESCE:
+		if (ops->quiesce) {
+			error = ops->quiesce(dev);
+			suspend_report_result(ops->quiesce, error);
+		}
+		break;
+	case PM_EVENT_HIBERNATE:
+		if (ops->poweroff) {
+			error = ops->poweroff(dev);
+			suspend_report_result(ops->poweroff, error);
+		}
+		break;
+	case PM_EVENT_THAW:
+		if (ops->thaw) {
+			error = ops->thaw(dev);
+			suspend_report_result(ops->thaw, error);
+		}
+		break;
+	case PM_EVENT_RESTORE:
+		if (ops->restore) {
+			error = ops->restore(dev);
+			suspend_report_result(ops->restore, error);
+		}
+		break;
+	case PM_EVENT_RECOVER:
+		if (ops->recover) {
+			error = ops->recover(dev);
+			suspend_report_result(ops->recover, error);
+		}
+		break;
+#endif /* CONFIG_HIBERNATION */
+	default:
+		error = -EINVAL;
+	}
+	return error;
+}
+
+static char *pm_verb(int event)
+{
+	switch (event) {
+	case PM_EVENT_SUSPEND:
+		return "suspend";
+	case PM_EVENT_RESUME:
+		return "resume";
+	case PM_EVENT_FREEZE:
+		return "freeze";
+	case PM_EVENT_QUIESCE:
+		return "quiesce";
+	case PM_EVENT_HIBERNATE:
+		return "hibernate";
+	case PM_EVENT_THAW:
+		return "thaw";
+	case PM_EVENT_RESTORE:
+		return "restore";
+	default:
+		return "(unknown PM event)";
+	}
+}
+
+static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
+{
+	dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
+		((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
+		", may wakeup" : "");
+}
+
 /*------------------------- Resume routines -------------------------*/
 
 /**
- *	resume_device_early - Power on one device (early resume).
+ *	resume_device_noirq - Power on one device (early resume).
  *	@dev:	Device.
+ *	@state: Operation to carry out.
  *
  *	Must be called with interrupts disabled.
  */
-static int resume_device_early(struct device *dev)
+static int resume_device_noirq(struct device *dev, pm_message_t state)
 {
 	int error = 0;
 
 	TRACE_DEVICE(dev);
 	TRACE_RESUME(0);
 
-	if (dev->bus && dev->bus->resume_early) {
-		dev_dbg(dev, "EARLY resume\n");
+	if (!dev->bus)
+		goto End;
+
+	if (dev->bus->pm_noirq) {
+		struct pm_ops *ops = dev->bus->pm_noirq;
+
+		pm_dev_dbg(dev, state, "EARLY ");
+		error = pm_op(dev, ops, state);
+		if (ops->complete)
+			ops->complete(dev);
+	} else if (dev->bus->resume_early) {
+		pm_dev_dbg(dev, state, "legacy EARLY ");
 		error = dev->bus->resume_early(dev);
 	}
-
+ End:
 	TRACE_RESUME(error);
 	return error;
 }
@@ -156,7 +273,7 @@ static int resume_device_early(struct de
  *
  *	Must be called with interrupts disabled and only one CPU running.
  */
-static void dpm_power_up(void)
+static void dpm_power_up(pm_message_t state)
 {
 
 	while (!list_empty(&dpm_off_irq)) {
@@ -164,7 +281,7 @@ static void dpm_power_up(void)
 		struct device *dev = to_device(entry);
 
 		list_move_tail(entry, &dpm_off);
-		resume_device_early(dev);
+		resume_device_noirq(dev, state);
 	}
 }
 
@@ -176,19 +293,46 @@ static void dpm_power_up(void)
  *
  *	Must be called with interrupts disabled.
  */
-void device_power_up(void)
+void device_power_up(pm_message_t state)
 {
 	sysdev_resume();
-	dpm_power_up();
+	dpm_power_up(state);
 }
 EXPORT_SYMBOL_GPL(device_power_up);
 
 /**
+ *	complete_device - Complete a PM transition for given device
+ *	@dev:	Device.
+ *	@state:	Power transition we are completing.
+ */
+static void complete_device(struct device *dev, pm_message_t state)
+{
+	down(&dev->sem);
+
+	if (dev->bus && dev->bus->pm && dev->bus->pm->complete) {
+		pm_dev_dbg(dev, state, "completing ");
+		dev->bus->pm->complete(dev);
+	}
+
+	if (dev->type && dev->type->pm && dev->type->pm->complete) {
+		pm_dev_dbg(dev, state, "completing type ");
+		dev->type->pm->complete(dev);
+	}
+
+	if (dev->class && dev->class->pm && dev->class->pm->complete) {
+		pm_dev_dbg(dev, state, "completing class ");
+		dev->class->pm->complete(dev);
+	}
+
+	up(&dev->sem);
+}
+
+/**
  *	resume_device - Restore state for one device.
  *	@dev:	Device.
- *
+ *	@state:	Operation to carry out.
  */
-static int resume_device(struct device *dev)
+static int resume_device(struct device *dev, pm_message_t state)
 {
 	int error = 0;
 
@@ -197,21 +341,40 @@ static int resume_device(struct device *
 
 	down(&dev->sem);
 
-	if (dev->bus && dev->bus->resume) {
-		dev_dbg(dev,"resuming\n");
-		error = dev->bus->resume(dev);
+	if (dev->bus) {
+		if (dev->bus->pm) {
+			pm_dev_dbg(dev, state, "");
+			error = pm_op(dev, dev->bus->pm, state);
+		} else if (dev->bus->resume) {
+			pm_dev_dbg(dev, state, "legacy ");
+			error = dev->bus->resume(dev);
+		}
+		if (error)
+			goto End;
 	}
 
-	if (!error && dev->type && dev->type->resume) {
-		dev_dbg(dev,"resuming\n");
-		error = dev->type->resume(dev);
+	if (dev->type) {
+		if (dev->type->pm) {
+			pm_dev_dbg(dev, state, "type ");
+			error = pm_op(dev, dev->type->pm, state);
+		} else if (dev->type->resume) {
+			pm_dev_dbg(dev, state, "legacy type ");
+			error = dev->type->resume(dev);
+		}
+		if (error)
+			goto End;
 	}
 
-	if (!error && dev->class && dev->class->resume) {
-		dev_dbg(dev,"class resume\n");
-		error = dev->class->resume(dev);
+	if (dev->class) {
+		if (dev->class->pm) {
+			pm_dev_dbg(dev, state, "class ");
+			error = pm_op(dev, dev->class->pm, state);
+		} else if (dev->class->resume) {
+			pm_dev_dbg(dev, state, "legacy class ");
+			error = dev->class->resume(dev);
+		}
 	}
-
+ End:
 	up(&dev->sem);
 
 	TRACE_RESUME(error);
@@ -226,9 +389,9 @@ static int resume_device(struct device *
  *	went through the early resume.
  *
  *	Take devices from the dpm_off_list, resume them,
- *	and put them on the dpm_locked list.
+ *	and put them on the dpm_active list.
  */
-static void dpm_resume(void)
+static void dpm_resume(pm_message_t state)
 {
 	mutex_lock(&dpm_list_mtx);
 	all_sleeping = false;
@@ -237,9 +400,10 @@ static void dpm_resume(void)
 		struct device *dev = to_device(entry);
 
 		list_move_tail(entry, &dpm_active);
-		dev->power.sleeping = false;
+		dev->power.status = DPM_ON;
 		mutex_unlock(&dpm_list_mtx);
-		resume_device(dev);
+		resume_device(dev, state);
+		complete_device(dev, state);
 		mutex_lock(&dpm_list_mtx);
 	}
 	mutex_unlock(&dpm_list_mtx);
@@ -267,14 +431,15 @@ static void unregister_dropped_devices(v
 
 /**
  *	device_resume - Restore state of each device in system.
+ *	@state: Operation to carry out.
  *
  *	Resume all the devices, unlock them all, and allow new
  *	devices to be registered once again.
  */
-void device_resume(void)
+void device_resume(pm_message_t state)
 {
 	might_sleep();
-	dpm_resume();
+	dpm_resume(state);
 	unregister_dropped_devices();
 }
 EXPORT_SYMBOL_GPL(device_resume);
@@ -282,37 +447,52 @@ EXPORT_SYMBOL_GPL(device_resume);
 
 /*------------------------- Suspend routines -------------------------*/
 
-static inline char *suspend_verb(u32 event)
+/**
+ *	resume_event - return a PM message representing the resume event
+ *	               corresponding to given sleep state.
+ *	@sleep_state - PM message representing a sleep state
+ */
+static pm_message_t resume_event(pm_message_t sleep_state)
 {
-	switch (event) {
-	case PM_EVENT_SUSPEND:	return "suspend";
-	case PM_EVENT_FREEZE:	return "freeze";
-	case PM_EVENT_PRETHAW:	return "prethaw";
-	default:		return "(unknown suspend event)";
+	switch (sleep_state.event) {
+	case PM_EVENT_SUSPEND:
+		return PMSG_RESUME;
+	case PM_EVENT_FREEZE:
+	case PM_EVENT_QUIESCE:
+		return PMSG_RECOVER;
+	case PM_EVENT_HIBERNATE:
+		return PMSG_RESTORE;
 	}
-}
-
-static void
-suspend_device_dbg(struct device *dev, pm_message_t state, char *info)
-{
-	dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event),
-		((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ?
-		", may wakeup" : "");
+	return PMSG_ON;
 }
 
 /**
- *	suspend_device_late - Shut down one device (late suspend).
+ *	suspend_device_noirq - Shut down one device (late suspend).
  *	@dev:	Device.
- *	@state:	Power state device is entering.
+ *	@state:	PM message representing the operation to perform.
  *
  *	This is called with interrupts off and only a single CPU running.
  */
-static int suspend_device_late(struct device *dev, pm_message_t state)
+static int suspend_device_noirq(struct device *dev, pm_message_t state)
 {
 	int error = 0;
 
-	if (dev->bus && dev->bus->suspend_late) {
-		suspend_device_dbg(dev, state, "LATE ");
+	if (!dev->bus)
+		return 0;
+
+	if (dev->bus->pm_noirq) {
+		struct pm_ops *ops = dev->bus->pm_noirq;
+
+		pm_dev_dbg(dev, state, "LATE ");
+		if (ops->prepare)
+			error = ops->prepare(dev);
+		if (!error) {
+			error = pm_op(dev, ops, state);
+			if (error && ops->complete)
+				ops->complete(dev);
+		}
+	} else if (dev->bus->suspend_late) {
+		pm_dev_dbg(dev, state, "legacy LATE ");
 		error = dev->bus->suspend_late(dev, state);
 		suspend_report_result(dev->bus->suspend_late, error);
 	}
@@ -321,7 +501,7 @@ static int suspend_device_late(struct de
 
 /**
  *	device_power_down - Shut down special devices.
- *	@state:		Power state to enter.
+ *	@state:	PM message representing the operation to perform.
  *
  *	Power down devices that require interrupts to be disabled
  *	and move them from the dpm_off list to the dpm_off_irq list.
@@ -337,7 +517,7 @@ int device_power_down(pm_message_t state
 		struct list_head *entry = dpm_off.prev;
 		struct device *dev = to_device(entry);
 
-		error = suspend_device_late(dev, state);
+		error = suspend_device_noirq(dev, state);
 		if (error) {
 			printk(KERN_ERR "Could not power down device %s: "
 					"error %d\n",
@@ -351,12 +531,50 @@ int device_power_down(pm_message_t state
 	if (!error)
 		error = sysdev_suspend(state);
 	if (error)
-		dpm_power_up();
+		dpm_power_up(resume_event(state));
 	return error;
 }
 EXPORT_SYMBOL_GPL(device_power_down);
 
 /**
+ *	prepare_device - Execute the ->prepare() callback(s) for given device.
+ *	@dev:	Device.
+ *	@state: PM operation we are preparing for.
+ */
+static int prepare_device(struct device *dev, pm_message_t state)
+{
+	int error = 0;
+
+	down(&dev->sem);
+
+	if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) {
+		pm_dev_dbg(dev, state, "preparing ");
+		error = dev->bus->pm->prepare(dev);
+		suspend_report_result(dev->bus->pm->prepare, error);
+		if (error)
+			goto End;
+	}
+
+	if (dev->type && dev->type->pm && dev->type->pm->prepare) {
+		pm_dev_dbg(dev, state, "preparing type ");
+		error = dev->type->pm->prepare(dev);
+		suspend_report_result(dev->type->pm->prepare, error);
+		if (error)
+			goto End;
+	}
+
+	if (dev->class && dev->class->pm && dev->class->pm->prepare) {
+		pm_dev_dbg(dev, state, "preparing class ");
+		error = dev->class->pm->prepare(dev);
+		suspend_report_result(dev->class->pm->prepare, error);
+	}
+ End:
+	up(&dev->sem);
+
+	return error;
+}
+
+/**
  *	suspend_device - Save state of one device.
  *	@dev:	Device.
  *	@state:	Power state device is entering.
@@ -367,29 +585,43 @@ static int suspend_device(struct device 
 
 	down(&dev->sem);
 
-	if (dev->power.power_state.event) {
-		dev_dbg(dev, "PM: suspend %d-->%d\n",
-			dev->power.power_state.event, state.event);
-	}
-
-	if (dev->class && dev->class->suspend) {
-		suspend_device_dbg(dev, state, "class ");
-		error = dev->class->suspend(dev, state);
-		suspend_report_result(dev->class->suspend, error);
+	if (dev->class) {
+		if (dev->class->pm) {
+			pm_dev_dbg(dev, state, "class ");
+			error = pm_op(dev, dev->class->pm, state);
+		} else if (dev->class->suspend) {
+			pm_dev_dbg(dev, state, "legacy class ");
+			error = dev->class->suspend(dev, state);
+			suspend_report_result(dev->class->suspend, error);
+		}
+		if (error)
+			goto End;
 	}
 
-	if (!error && dev->type && dev->type->suspend) {
-		suspend_device_dbg(dev, state, "type ");
-		error = dev->type->suspend(dev, state);
-		suspend_report_result(dev->type->suspend, error);
+	if (dev->type) {
+		if (dev->type->pm) {
+			pm_dev_dbg(dev, state, "type ");
+			error = pm_op(dev, dev->type->pm, state);
+		} else if (dev->type->suspend) {
+			pm_dev_dbg(dev, state, "legacy type ");
+			error = dev->type->suspend(dev, state);
+			suspend_report_result(dev->type->suspend, error);
+		}
+		if (error)
+			goto End;
 	}
 
-	if (!error && dev->bus && dev->bus->suspend) {
-		suspend_device_dbg(dev, state, "");
-		error = dev->bus->suspend(dev, state);
-		suspend_report_result(dev->bus->suspend, error);
+	if (dev->bus) {
+		if (dev->bus->pm) {
+			pm_dev_dbg(dev, state, "");
+			error = pm_op(dev, dev->bus->pm, state);
+		} else if (dev->bus->suspend) {
+			pm_dev_dbg(dev, state, "legacy ");
+			error = dev->bus->suspend(dev, state);
+			suspend_report_result(dev->bus->suspend, error);
+		}
 	}
-
+ End:
 	up(&dev->sem);
 
 	return error;
@@ -399,13 +631,8 @@ static int suspend_device(struct device 
  *	dpm_suspend - Suspend every device.
  *	@state:	Power state to put each device in.
  *
- *	Walk the dpm_locked list.  Suspend each device and move it
+ *	Walk the dpm_active list.  Suspend each device and move it
  *	to the dpm_off list.
- *
- *	(For historical reasons, if it returns -EAGAIN, that used to mean
- *	that the device would be called again with interrupts disabled.
- *	These days, we use the "suspend_late()" callback for that, so we
- *	print a warning and consider it an error).
  */
 static int dpm_suspend(pm_message_t state)
 {
@@ -416,30 +643,53 @@ static int dpm_suspend(pm_message_t stat
 		struct list_head *entry = dpm_active.prev;
 		struct device *dev = to_device(entry);
 
-		WARN_ON(dev->parent && dev->parent->power.sleeping);
+		WARN_ON(dev->parent && dev->parent->power.status == DPM_OFF);
+		dev->power.status = DPM_SUSPENDING;
+		mutex_unlock(&dpm_list_mtx);
+
+		error = prepare_device(dev, state);
 
-		dev->power.sleeping = true;
+		mutex_lock(&dpm_list_mtx);
+		if (error) {
+			dev->power.status = DPM_ON;
+			if (error == -EAGAIN)
+				continue;
+			printk(KERN_ERR "Could not prepare device %s "
+				"for suspend: error %d\n",
+				kobject_name(&dev->kobj), error);
+			goto Unlock;
+		}
+		if (dev->power.status == DPM_ON) {
+			/* Child added during prepare_device() */
+			mutex_unlock(&dpm_list_mtx);
+
+			complete_device(dev, resume_event(state));
+
+			mutex_lock(&dpm_list_mtx);
+			continue;
+		}
+		dev->power.status = DPM_OFF;
 		mutex_unlock(&dpm_list_mtx);
+
 		error = suspend_device(dev, state);
+
 		mutex_lock(&dpm_list_mtx);
 		if (error) {
+			dev->power.status = DPM_ON;
 			printk(KERN_ERR "Could not suspend device %s: "
-					"error %d%s\n",
-					kobject_name(&dev->kobj),
-					error,
-					(error == -EAGAIN ?
-					" (please convert to suspend_late)" :
-					""));
-			dev->power.sleeping = false;
-			break;
+				"error %d\n", kobject_name(&dev->kobj), error);
+			mutex_unlock(&dpm_list_mtx);
+
+			complete_device(dev, resume_event(state));
+			goto End;
 		}
 		if (!list_empty(&dev->power.entry))
 			list_move(&dev->power.entry, &dpm_off);
 	}
-	if (!error)
-		all_sleeping = true;
+	all_sleeping = true;
+ Unlock:
 	mutex_unlock(&dpm_list_mtx);
-
+ End:
 	return error;
 }
 
@@ -447,8 +697,7 @@ static int dpm_suspend(pm_message_t stat
  *	device_suspend - Save state and stop all devices in system.
  *	@state: new power management state
  *
- *	Prevent new devices from being registered, then lock all devices
- *	and suspend them.
+ *	Prepare and suspend all devices.
  */
 int device_suspend(pm_message_t state)
 {
@@ -457,7 +706,7 @@ int device_suspend(pm_message_t state)
 	might_sleep();
 	error = dpm_suspend(state);
 	if (error)
-		device_resume();
+		device_resume(resume_event(state));
 	return error;
 }
 EXPORT_SYMBOL_GPL(device_suspend);
Index: linux-2.6/include/linux/device.h
===================================================================
--- linux-2.6.orig/include/linux/device.h
+++ linux-2.6/include/linux/device.h
@@ -69,6 +69,9 @@ struct bus_type {
 	int (*resume_early)(struct device *dev);
 	int (*resume)(struct device *dev);
 
+	struct pm_ops *pm;
+	struct pm_ops *pm_noirq;
+
 	struct bus_type_private *p;
 };
 
@@ -202,6 +205,8 @@ struct class {
 
 	int (*suspend)(struct device *dev, pm_message_t state);
 	int (*resume)(struct device *dev);
+
+	struct pm_ops *pm;
 };
 
 extern int __must_check class_register(struct class *class);
@@ -345,8 +350,11 @@ struct device_type {
 	struct attribute_group **groups;
 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
 	void (*release)(struct device *dev);
+
 	int (*suspend)(struct device *dev, pm_message_t state);
 	int (*resume)(struct device *dev);
+
+	struct pm_ops *pm;
 };
 
 /* interface for exporting device attributes */
Index: linux-2.6/kernel/power/disk.c
===================================================================
--- linux-2.6.orig/kernel/power/disk.c
+++ linux-2.6/kernel/power/disk.c
@@ -224,7 +224,7 @@ static int create_image(int platform_mod
 	/* NOTE:  device_power_up() is just a resume() for devices
 	 * that suspended with irqs off ... no overall powerup.
 	 */
-	device_power_up();
+	device_power_up(in_suspend ? PMSG_RECOVER : PMSG_RESTORE);
  Enable_irqs:
 	local_irq_enable();
 	return error;
@@ -280,7 +280,7 @@ int hibernation_snapshot(int platform_mo
  Finish:
 	platform_finish(platform_mode);
  Resume_devices:
-	device_resume();
+	device_resume(in_suspend ? PMSG_RECOVER : PMSG_RESTORE);
  Resume_console:
 	resume_console();
  Close:
@@ -301,7 +301,7 @@ static int resume_target_kernel(void)
 	int error;
 
 	local_irq_disable();
-	error = device_power_down(PMSG_PRETHAW);
+	error = device_power_down(PMSG_QUIESCE);
 	if (error) {
 		printk(KERN_ERR "PM: Some devices failed to power down, "
 			"aborting resume\n");
@@ -329,7 +329,7 @@ static int resume_target_kernel(void)
 	swsusp_free();
 	restore_processor_state();
 	touch_softlockup_watchdog();
-	device_power_up();
+	device_power_up(PMSG_THAW);
  Enable_irqs:
 	local_irq_enable();
 	return error;
@@ -350,7 +350,7 @@ int hibernation_restore(int platform_mod
 
 	pm_prepare_console();
 	suspend_console();
-	error = device_suspend(PMSG_PRETHAW);
+	error = device_suspend(PMSG_QUIESCE);
 	if (error)
 		goto Finish;
 
@@ -362,7 +362,7 @@ int hibernation_restore(int platform_mod
 		enable_nonboot_cpus();
 	}
 	platform_restore_cleanup(platform_mode);
-	device_resume();
+	device_resume(PMSG_RECOVER);
  Finish:
 	resume_console();
 	pm_restore_console();
@@ -419,7 +419,7 @@ int hibernation_platform_enter(void)
  Finish:
 	hibernation_ops->finish();
  Resume_devices:
-	device_resume();
+	device_resume(PMSG_RESTORE);
  Resume_console:
 	resume_console();
  Close:
Index: linux-2.6/kernel/power/main.c
===================================================================
--- linux-2.6.orig/kernel/power/main.c
+++ linux-2.6/kernel/power/main.c
@@ -239,7 +239,7 @@ static int suspend_enter(suspend_state_t
 	if (!suspend_test(TEST_CORE))
 		error = suspend_ops->enter(state);
 
-	device_power_up();
+	device_power_up(PMSG_RESUME);
  Done:
 	arch_suspend_enable_irqs();
 	BUG_ON(irqs_disabled());
@@ -291,7 +291,7 @@ int suspend_devices_and_enter(suspend_st
 	if (suspend_ops->finish)
 		suspend_ops->finish();
  Resume_devices:
-	device_resume();
+	device_resume(PMSG_RESUME);
  Resume_console:
 	resume_console();
  Close:
Index: linux-2.6/arch/x86/kernel/apm_32.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apm_32.c
+++ linux-2.6/arch/x86/kernel/apm_32.c
@@ -1208,9 +1208,9 @@ static int suspend(int vetoable)
 	if (err != APM_SUCCESS)
 		apm_error("suspend", err);
 	err = (err == APM_SUCCESS) ? 0 : -EIO;
-	device_power_up();
+	device_power_up(PMSG_RESUME);
 	local_irq_enable();
-	device_resume();
+	device_resume(PMSG_RESUME);
 	queue_event(APM_NORMAL_RESUME, NULL);
  out:
 	spin_lock(&user_list_lock);

[RFC][PATCH 2/3] PM: New suspend and hibernation callbacks for platform bus type

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Implement new suspend and hibernation callbacks for the platform bus
type.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/base/platform.c         |  444 ++++++++++++++++++++++++++++++++++++++--
 include/linux/platform_device.h |    2 
 2 files changed, 425 insertions(+), 21 deletions(-)

Index: linux-2.6/include/linux/platform_device.h
===================================================================
--- linux-2.6.orig/include/linux/platform_device.h
+++ linux-2.6/include/linux/platform_device.h
@@ -53,6 +53,8 @@ struct platform_driver {
 	int (*suspend_late)(struct platform_device *, pm_message_t state);
 	int (*resume_early)(struct platform_device *);
 	int (*resume)(struct platform_device *);
+	struct pm_ops *pm;
+	struct pm_ops *pm_noirq;
 	struct device_driver driver;
 };
 
Index: linux-2.6/drivers/base/platform.c
===================================================================
--- linux-2.6.orig/drivers/base/platform.c
+++ linux-2.6/drivers/base/platform.c
@@ -560,61 +560,463 @@ static int platform_match(struct device 
 	return (strncmp(pdev->name, drv->name, BUS_ID_SIZE) == 0);
 }
 
-static int platform_suspend(struct device *dev, pm_message_t mesg)
+#ifdef CONFIG_PM_SLEEP
+static int platform_pm_prepare(struct device *dev)
 {
+	struct platform_driver *drv;
 	int ret = 0;
 
-	if (dev->driver && dev->driver->suspend)
-		ret = dev->driver->suspend(dev, mesg);
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm && drv->pm->prepare)
+		ret = drv->pm->prepare(dev);
+
+	return ret;
+}
+
+static int platform_pm_prepare_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq && drv->pm_noirq->prepare)
+		ret = drv->pm_noirq->prepare(dev);
+
+	return ret;
+}
+
+static void platform_pm_complete(struct device *dev)
+{
+	struct platform_driver *drv;
+
+	if (!dev->driver)
+		return;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm && drv->pm->complete)
+		drv->pm->complete(dev);
+}
+
+static void platform_pm_complete_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+
+	if (!dev->driver)
+		return;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq && drv->pm_noirq->complete)
+		drv->pm_noirq->complete(dev);
+}
+
+#ifdef CONFIG_SUSPEND
+static int platform_pm_suspend(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->suspend)
+			ret = drv->pm->suspend(dev);
+	} else if (dev->driver->suspend) {
+		/* Legacy mechanism */
+		ret = dev->driver->suspend(dev, PMSG_SUSPEND);
+	}
+
+	return ret;
+}
+
+static int platform_pm_suspend_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->suspend)
+			ret = drv->pm_noirq->suspend(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->suspend_late)
+			ret = drv->suspend_late(pdev, PMSG_SUSPEND);
+	}
+
+	return ret;
+}
+
+static int platform_pm_resume(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->resume)
+			ret = drv->pm->resume(dev);
+	} else if (dev->driver->resume) {
+		/* Legacy mechanism */
+		ret = dev->driver->resume(dev);
+	}
 
 	return ret;
 }
 
-static int platform_suspend_late(struct device *dev, pm_message_t mesg)
+static int platform_pm_resume_noirq(struct device *dev)
 {
-	struct platform_driver *drv = to_platform_driver(dev->driver);
-	struct platform_device *pdev;
+	struct platform_driver *drv;
 	int ret = 0;
 
-	pdev = container_of(dev, struct platform_device, dev);
-	if (dev->driver && drv->suspend_late)
-		ret = drv->suspend_late(pdev, mesg);
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->resume)
+			ret = drv->pm_noirq->resume(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->resume_early)
+			ret = drv->resume_early(pdev);
+	}
 
 	return ret;
 }
+#endif /* CONFIG_SUSPEND */
 
-static int platform_resume_early(struct device *dev)
+#ifdef CONFIG_HIBERNATION
+static int platform_pm_freeze(struct device *dev)
 {
-	struct platform_driver *drv = to_platform_driver(dev->driver);
-	struct platform_device *pdev;
+	struct platform_driver *drv;
 	int ret = 0;
 
-	pdev = container_of(dev, struct platform_device, dev);
-	if (dev->driver && drv->resume_early)
-		ret = drv->resume_early(pdev);
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->freeze)
+			ret = drv->pm->freeze(dev);
+	} else if (dev->driver->suspend) {
+		/* Legacy mechanism */
+		ret = dev->driver->suspend(dev, PMSG_FREEZE);
+	}
 
 	return ret;
 }
 
-static int platform_resume(struct device *dev)
+static int platform_pm_freeze_noirq(struct device *dev)
 {
+	struct platform_driver *drv;
 	int ret = 0;
 
-	if (dev->driver && dev->driver->resume)
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->freeze)
+			ret = drv->pm_noirq->freeze(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->suspend_late)
+			ret = drv->suspend_late(pdev, PMSG_FREEZE);
+	}
+
+	return ret;
+}
+
+static int platform_pm_thaw(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->thaw)
+			ret = drv->pm->thaw(dev);
+	} else if (dev->driver->resume) {
+		/* Legacy mechanism */
 		ret = dev->driver->resume(dev);
+	}
 
 	return ret;
 }
 
+static int platform_pm_thaw_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->thaw)
+			ret = drv->pm_noirq->thaw(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->resume_early)
+			ret = drv->resume_early(pdev);
+	}
+
+	return ret;
+}
+
+static int platform_pm_poweroff(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->poweroff)
+			ret = drv->pm->poweroff(dev);
+	} else if (dev->driver->suspend) {
+		/* Legacy mechanism */
+		ret = dev->driver->suspend(dev, PMSG_HIBERNATE);
+	}
+
+	return ret;
+}
+
+static int platform_pm_poweroff_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->poweroff)
+			ret = drv->pm_noirq->poweroff(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->suspend_late)
+			ret = drv->suspend_late(pdev, PMSG_HIBERNATE);
+	}
+
+	return ret;
+}
+
+static int platform_pm_quiesce(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->quiesce)
+			ret = drv->pm->quiesce(dev);
+	} else if (dev->driver->suspend) {
+		/* Legacy mechanism */
+		ret = dev->driver->suspend(dev, PMSG_QUIESCE);
+	}
+
+	return ret;
+}
+
+static int platform_pm_quiesce_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->quiesce)
+			ret = drv->pm_noirq->quiesce(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->suspend_late)
+			ret = drv->suspend_late(pdev, PMSG_QUIESCE);
+	}
+
+	return ret;
+}
+
+static int platform_pm_restore(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->restore)
+			ret = drv->pm->restore(dev);
+	} else if (dev->driver->resume) {
+		/* Legacy mechanism */
+		ret = dev->driver->resume(dev);
+	}
+
+	return ret;
+}
+
+static int platform_pm_restore_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->restore)
+			ret = drv->pm_noirq->restore(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->resume_early)
+			ret = drv->resume_early(pdev);
+	}
+
+	return ret;
+}
+
+static int platform_pm_recover(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm) {
+		if (drv->pm->recover)
+			ret = drv->pm->recover(dev);
+	} else if (dev->driver->resume) {
+		/* Legacy mechanism */
+		ret = dev->driver->resume(dev);
+	}
+
+	return ret;
+}
+
+static int platform_pm_recover_noirq(struct device *dev)
+{
+	struct platform_driver *drv;
+	int ret = 0;
+
+	if (!dev->driver)
+		return 0;
+
+	drv = to_platform_driver(dev->driver);
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->recover)
+			ret = drv->pm_noirq->recover(dev);
+	} else {
+		/* Legacy mechanism */
+		struct platform_device *pdev;
+
+		pdev = container_of(dev, struct platform_device, dev);
+		if (drv->resume_early)
+			ret = drv->resume_early(pdev);
+	}
+
+	return ret;
+}
+#endif /* CONFIG_HIBERNATION */
+#endif /* CONFIG_PM_SLEEP */
+
+struct pm_ops platform_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.prepare = platform_pm_prepare,
+	.complete = platform_pm_complete,
+#endif
+#ifdef CONFIG_SUSPEND
+	.suspend = platform_pm_suspend,
+	.resume = platform_pm_resume,
+#endif
+#ifdef CONFIG_HIBERNATION
+	.freeze = platform_pm_freeze,
+	.thaw = platform_pm_thaw,
+	.poweroff = platform_pm_poweroff,
+	.quiesce = platform_pm_quiesce,
+	.restore = platform_pm_restore,
+	.recover = platform_pm_recover,
+#endif
+};
+
+struct pm_ops platform_pm_ops_noirq = {
+#ifdef CONFIG_PM_SLEEP
+	.prepare = platform_pm_prepare_noirq,
+	.complete = platform_pm_complete_noirq,
+#endif
+#ifdef CONFIG_SUSPEND
+	.suspend = platform_pm_suspend_noirq,
+	.resume = platform_pm_resume_noirq,
+#endif
+#ifdef CONFIG_HIBERNATION
+	.freeze = platform_pm_freeze_noirq,
+	.thaw = platform_pm_thaw_noirq,
+	.poweroff = platform_pm_poweroff_noirq,
+	.quiesce = platform_pm_quiesce_noirq,
+	.restore = platform_pm_restore_noirq,
+	.recover = platform_pm_recover_noirq,
+#endif
+};
+
 struct bus_type platform_bus_type = {
 	.name		= "platform",
 	.dev_attrs	= platform_dev_attrs,
 	.match		= platform_match,
 	.uevent		= platform_uevent,
-	.suspend	= platform_suspend,
-	.suspend_late	= platform_suspend_late,
-	.resume_early	= platform_resume_early,
-	.resume		= platform_resume,
+	.pm		= &platform_pm_ops,
+	.pm_noirq	= &platform_pm_ops_noirq,
 };
 EXPORT_SYMBOL_GPL(platform_bus_type);
 

[RFC][PATCH 3/3] PM: New suspend and hibernation callbacks for PCI bus type

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rjw@sisk.pl>

Implement new suspend and hibernation callbacks for the PCI busi type.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/pci/pci-driver.c |  497 ++++++++++++++++++++++++++++++++++++++++++-----
 include/linux/pci.h      |    2 
 2 files changed, 453 insertions(+), 46 deletions(-)

Index: linux-2.6/drivers/pci/pci-driver.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-driver.c
+++ linux-2.6/drivers/pci/pci-driver.c
@@ -271,45 +271,78 @@ static int pci_device_remove(struct devi
 	return 0;
 }
 
-static int pci_device_suspend(struct device * dev, pm_message_t state)
+static void pci_device_shutdown(struct device *dev)
 {
-	struct pci_dev * pci_dev = to_pci_dev(dev);
-	struct pci_driver * drv = pci_dev->driver;
-	int i = 0;
-
-	if (drv && drv->suspend) {
-		i = drv->suspend(pci_dev, state);
-		suspend_report_result(drv->suspend, i);
-	} else {
-		pci_save_state(pci_dev);
-		/*
-		 * mark its power state as "unknown", since we don't know if
-		 * e.g. the BIOS will change its device state when we suspend.
-		 */
-		if (pci_dev->current_state == PCI_D0)
-			pci_dev->current_state = PCI_UNKNOWN;
-	}
-	return i;
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+
+	if (drv && drv->shutdown)
+		drv->shutdown(pci_dev);
 }
 
-static int pci_device_suspend_late(struct device * dev, pm_message_t state)
+#ifdef CONFIG_PM_SLEEP
+static int pci_pm_prepare(struct device *dev)
 {
-	struct pci_dev * pci_dev = to_pci_dev(dev);
-	struct pci_driver * drv = pci_dev->driver;
-	int i = 0;
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
 
-	if (drv && drv->suspend_late) {
-		i = drv->suspend_late(pci_dev, state);
-		suspend_report_result(drv->suspend_late, i);
-	}
-	return i;
+	if (drv && drv->pm && drv->pm->prepare)
+		error = drv->pm->prepare(dev);
+
+	return error;
+}
+
+static int pci_pm_prepare_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (drv && drv->pm_noirq && drv->pm_noirq->prepare)
+		error = drv->pm_noirq->prepare(dev);
+
+	return error;
+}
+
+static void pci_pm_complete(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+
+	if (drv && drv->pm && drv->pm->complete)
+		drv->pm->complete(dev);
+}
+
+static void pci_pm_complete_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+
+	if (drv && drv->pm_noirq && drv->pm_noirq->complete)
+		drv->pm_noirq->complete(dev);
 }
 
 /*
- * Default resume method for devices that have no driver provided resume,
+ * Default "suspend" method for devices that have no driver provided suspend,
  * or not even a driver at all.
  */
-static int pci_default_resume(struct pci_dev *pci_dev)
+static void pci_default_pm_suspend(struct pci_dev *pci_dev)
+{
+	pci_save_state(pci_dev);
+	/*
+	 * mark its power state as "unknown", since we don't know if
+	 * e.g. the BIOS will change its device state when we suspend.
+	 */
+	if (pci_dev->current_state == PCI_D0)
+		pci_dev->current_state = PCI_UNKNOWN;
+}
+
+/*
+ * Default "resume" method for devices that have no driver provided resume,
+ * or not even a driver at all.
+ */
+static int pci_default_pm_resume(struct pci_dev *pci_dev)
 {
 	int retval = 0;
 
@@ -324,40 +357,376 @@ static int pci_default_resume(struct pci
 	return retval;
 }
 
-static int pci_device_resume(struct device * dev)
+#ifdef CONFIG_SUSPEND
+static int pci_pm_suspend(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv) {
+		pci_default_pm_suspend(pci_dev);
+		return 0;
+	}
+
+	if (drv->pm) {
+		if (drv->pm->suspend) {
+			error = drv->pm->suspend(dev);
+			suspend_report_result(drv->pm->suspend, error);
+		} else {
+			pci_default_pm_suspend(pci_dev);
+		}
+	} else {
+		/* Legacy mechanism */
+		if (drv->suspend) {
+			error = drv->suspend(pci_dev, PMSG_SUSPEND);
+			suspend_report_result(drv->suspend, error);
+		} else {
+			pci_default_pm_suspend(pci_dev);
+		}
+	}
+
+	return error;
+}
+
+static int pci_pm_suspend_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->suspend) {
+			error = drv->pm_noirq->suspend(dev);
+			suspend_report_result(drv->pm_noirq->suspend, error);
+		}
+	} else if (drv->suspend_late) {
+		/* Legacy mechanism */
+		error = drv->suspend_late(pci_dev, PMSG_SUSPEND);
+		suspend_report_result(drv->suspend_late, error);
+	}
+
+	return error;
+}
+
+static int pci_pm_resume(struct device *dev)
 {
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
 	int error;
-	struct pci_dev * pci_dev = to_pci_dev(dev);
-	struct pci_driver * drv = pci_dev->driver;
 
-	if (drv && drv->resume)
+	if (!drv)
+		return pci_default_pm_resume(pci_dev);
+
+	if (drv->pm) {
+		error = drv->pm->resume ?
+			drv->pm->resume(dev) : pci_default_pm_resume(pci_dev);
+	} else {
+		/* Legacy mechanism */
+		error = drv->resume ?
+			drv->resume(pci_dev) : pci_default_pm_resume(pci_dev);
+	}
+
+	return error;
+}
+
+static int pci_pm_resume_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	pci_fixup_device(pci_fixup_resume, pci_dev);
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->resume)
+			error = drv->pm_noirq->resume(dev);
+	} else if (drv->resume_early) {
+		/* Legacy mechanism */
+		error = drv->resume_early(pci_dev);
+	}
+
+	return error;
+}
+#endif /* CONFIG_SUSPEND */
+
+#ifdef CONFIG_HIBERNATION
+static int pci_pm_freeze(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv) {
+		pci_default_pm_suspend(pci_dev);
+		return 0;
+	}
+
+	if (drv->pm) {
+		if (drv->pm->freeze) {
+			error = drv->pm->freeze(dev);
+			suspend_report_result(drv->pm->freeze, error);
+		} else {
+			pci_default_pm_suspend(pci_dev);
+		}
+	} else {
+		/* Legacy mechanism */
+		if (drv->suspend) {
+			error = drv->suspend(pci_dev, PMSG_FREEZE);
+			suspend_report_result(drv->suspend, error);
+		} else {
+			pci_default_pm_suspend(pci_dev);
+		}
+	}
+
+	return error;
+}
+
+static int pci_pm_freeze_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->freeze) {
+			error = drv->pm_noirq->freeze(dev);
+			suspend_report_result(drv->pm_noirq->freeze, error);
+		}
+	} else if (drv->suspend_late) {
+		/* Legacy mechanism */
+		error = drv->suspend_late(pci_dev, PMSG_FREEZE);
+		suspend_report_result(drv->suspend_late, error);
+	}
+
+	return error;
+}
+
+static int pci_pm_thaw(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->thaw)
+			error =  drv->pm->thaw(dev);
+	} else if (drv->resume) {
+		/* Legacy mechanism */
 		error = drv->resume(pci_dev);
-	else
-		error = pci_default_resume(pci_dev);
+	}
+
+	return error;
+}
+
+static int pci_pm_thaw_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->thaw)
+			error = drv->pm_noirq->thaw(dev);
+	} else if (drv->resume_early) {
+		/* Legacy mechanism */
+		error = drv->resume_early(pci_dev);
+	}
+
+	return error;
+}
+
+static int pci_pm_poweroff(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->poweroff) {
+			error = drv->pm->poweroff(dev);
+			suspend_report_result(drv->pm->poweroff, error);
+		}
+	} else if (drv->suspend) {
+		/* Legacy mechanism */
+		error = drv->suspend(pci_dev, PMSG_HIBERNATE);
+		suspend_report_result(drv->suspend, error);
+	}
+
+	return error;
+}
+
+static int pci_pm_poweroff_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->poweroff) {
+			error = drv->pm_noirq->poweroff(dev);
+			suspend_report_result(drv->pm_noirq->poweroff, error);
+		}
+	} else if (drv->suspend_late) {
+		/* Legacy mechanism */
+		error = drv->suspend_late(pci_dev, PMSG_HIBERNATE);
+		suspend_report_result(drv->suspend_late, error);
+	}
+
+	return error;
+}
+
+static int pci_pm_quiesce(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->quiesce) {
+			error = drv->pm->quiesce(dev);
+			suspend_report_result(drv->pm->quiesce, error);
+		}
+	} else if (drv->suspend) {
+		/* Legacy mechanism */
+		error = drv->suspend(pci_dev, PMSG_QUIESCE);
+		suspend_report_result(drv->suspend, error);
+	}
+
+	return error;
+}
+
+static int pci_pm_quiesce_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->quiesce) {
+			error = drv->pm_noirq->quiesce(dev);
+			suspend_report_result(drv->pm_noirq->quiesce, error);
+		}
+	} else if (drv->suspend_late) {
+		/* Legacy mechanism */
+		error = drv->suspend_late(pci_dev, PMSG_QUIESCE);
+		suspend_report_result(drv->suspend_late, error);
+	}
+
+	return error;
+}
+
+static int pci_pm_restore(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error;
+
+	if (!drv)
+		return pci_default_pm_resume(pci_dev);
+
+	if (drv->pm) {
+		error = drv->pm->restore ?
+			drv->pm->restore(dev) : pci_default_pm_resume(pci_dev);
+	} else {
+		/* Legacy mechanism */
+		error = drv->resume ?
+			drv->resume(pci_dev) : pci_default_pm_resume(pci_dev);
+	}
+
 	return error;
 }
 
-static int pci_device_resume_early(struct device * dev)
+static int pci_pm_restore_noirq(struct device *dev)
 {
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
 	int error = 0;
-	struct pci_dev * pci_dev = to_pci_dev(dev);
-	struct pci_driver * drv = pci_dev->driver;
 
 	pci_fixup_device(pci_fixup_resume, pci_dev);
 
-	if (drv && drv->resume_early)
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->restore)
+			error = drv->pm_noirq->restore(dev);
+	} else if (drv->resume_early) {
+		/* Legacy mechanism */
 		error = drv->resume_early(pci_dev);
+	}
+
 	return error;
 }
 
-static void pci_device_shutdown(struct device *dev)
+static int pci_pm_recover(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
 
-	if (drv && drv->shutdown)
-		drv->shutdown(pci_dev);
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->recover)
+			error = drv->pm->recover(dev);
+	} else if (drv->resume) {
+		/* Legacy mechanism */
+		error = drv->resume(pci_dev);
+	}
+
+	return error;
+}
+
+static int pci_pm_recover_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+	int error = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm_noirq) {
+		if (drv->pm_noirq->recover)
+			error = drv->pm_noirq->recover(dev);
+	} else if (drv->resume_early) {
+		/* Legacy mechanism */
+		error = drv->resume_early(pci_dev);
+	}
+
+	return error;
 }
+#endif /* CONFIG_HIBERNATION */
+#endif /* CONFIG_PM_SLEEP */
 
 /**
  * __pci_register_driver - register a new pci driver
@@ -500,18 +869,54 @@ int pci_uevent(struct device *dev, struc
 }
 #endif
 
+struct pm_ops pci_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.prepare = pci_pm_prepare,
+	.complete = pci_pm_complete,
+#endif
+#ifdef CONFIG_SUSPEND
+	.suspend = pci_pm_suspend,
+	.resume = pci_pm_resume,
+#endif
+#ifdef CONFIG_HIBERNATION
+	.freeze = pci_pm_freeze,
+	.thaw = pci_pm_thaw,
+	.poweroff = pci_pm_poweroff,
+	.quiesce = pci_pm_quiesce,
+	.restore = pci_pm_restore,
+	.recover = pci_pm_recover,
+#endif
+};
+
+struct pm_ops pci_pm_ops_noirq = {
+#ifdef CONFIG_PM_SLEEP
+	.prepare = pci_pm_prepare_noirq,
+	.complete = pci_pm_complete_noirq,
+#endif
+#ifdef CONFIG_SUSPEND
+	.suspend = pci_pm_suspend_noirq,
+	.resume = pci_pm_resume_noirq,
+#endif
+#ifdef CONFIG_HIBERNATION
+	.freeze = pci_pm_freeze_noirq,
+	.thaw = pci_pm_thaw_noirq,
+	.poweroff = pci_pm_poweroff_noirq,
+	.quiesce = pci_pm_quiesce_noirq,
+	.restore = pci_pm_restore_noirq,
+	.recover = pci_pm_recover_noirq,
+#endif
+};
+
 struct bus_type pci_bus_type = {
 	.name		= "pci",
 	.match		= pci_bus_match,
 	.uevent		= pci_uevent,
 	.probe		= pci_device_probe,
 	.remove		= pci_device_remove,
-	.suspend	= pci_device_suspend,
-	.suspend_late	= pci_device_suspend_late,
-	.resume_early	= pci_device_resume_early,
-	.resume		= pci_device_resume,
 	.shutdown	= pci_device_shutdown,
 	.dev_attrs	= pci_dev_attrs,
+	.pm		= &pci_pm_ops,
+	.pm_noirq	= &pci_pm_ops_noirq,
 };
 
 static int __init pci_driver_init(void)
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -382,6 +382,8 @@ struct pci_driver {
 	int  (*resume) (struct pci_dev *dev);	                /* Device woken up */
 	void (*shutdown) (struct pci_dev *dev);
 
+	struct pm_ops *pm;
+	struct pm_ops *pm_noirq;
 	struct pci_error_handlers *err_handler;
 	struct device_driver	driver;
 	struct pci_dynids dynids;

Re: [RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks

[Pavel Machek]

Hi!

> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACK.

> + * The externally visible transitions are handled with the help of the following
> + * callbacks included in this structure:
> + *
> + * @prepare: Prepare the device for the upcoming transition, but do NOT change
> + *	its hardware state.  Prevent new children of the device from being
> + *	registered and prevent new calls to the probe method from being made
> + *	after @prepare() returns.  Also, if a concurrent child registration
> + *	or a call to the probe method already in progress is detected by
> + *	@prepare(), it may return -EAGAIN, so that the PM core can execute it
> + *	once again (e.g. after suspending the newly registered child) to recover
> + *	from the race condition. This method is executed for all kinds of
> + *	suspend transitions and is immediately followed by one of the suspend
> + *	callbacks: @suspend(), @freeze(), @poweroff(), or @quiesce().
> + *
> + * @complete: Undo the changes made by @prepare().  This method is executed for
> + *	all kinds of resume transitions, immediately following one of the resume
> + *	callbacks: @resume(), @thaw(), @restore(), or @recover().  Also executed
> + *	if a suspend callback (@suspend(), @freeze(), @poweroff(), @quiesce())
> + *	immediately following a successful @prepare() fails OR if a new child
> + *	of the device has been registered during @prepare().

So... we do prepare() but it detects new child, so it returns -EAGAIN.
  so we call complete() based on description above
...and then we call prepare() to suspend again?

> + * @suspend: Executed before putting the system into a sleep state in which the
> + *	contents of main memory are preserved.  Quiesce the device, put it into

content....is?

> + * @resume: Executed after waking the system up from a sleep state in which the
> + *	contents of main memory were preserved.  Put the device into the

content...is?

> + * @freeze: Hibernation-specific, executed before creating a hibernation image.
> + *	Quiesce operations so that a consistent image can be created, but do NOT
> + *	otherwise put the device into a low power device state and do NOT emit
> + *	system wakeup events.  Save in main memory the device settings to be

"Save device settings (used by @restore()) into main memory"?

> + * @quiesce: Hibernation-specific, executed after loading a hibernation image
> + *	and before restoring the contents of main memory from it.  Quiesce
> + *	operations so that the contents of main memory can be restored from the

operations, so ?
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
pomozte zachranit klanovicky les:  http://www.ujezdskystrom.info/

Re: [RFC][PATCH 2/3] PM: New suspend and hibernation callbacks for platform bus type

[Pavel Machek]

On Mon 2008-03-17 00:24:22, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Implement new suspend and hibernation callbacks for the platform bus
> type.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACK... but... this is getting quite big:

>  drivers/base/platform.c         |  444 ++++++++++++++++++++++++++++++++++++++--
>  include/linux/platform_device.h |    2

...I hope cleanups in drivers are worth it...

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
pomozte zachranit klanovicky les:  http://www.ujezdskystrom.info/

Re: [RFC][PATCH 3/3] PM: New suspend and hibernation callbacks for PCI bus type

[Pavel Machek]

On Mon 2008-03-17 00:25:15, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Implement new suspend and hibernation callbacks for the PCI busi type.

"bus", I guess.

> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACK.

> ---
>  drivers/pci/pci-driver.c |  497 ++++++++++++++++++++++++++++++++++++++++++-----
>  include/linux/pci.h      |    2 
>  2 files changed, 453 insertions(+), 46 deletions(-)

...but big, too :-(.
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
pomozte zachranit klanovicky les:  http://www.ujezdskystrom.info/

Re: [RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks

[Greg KH]

On Mon, Mar 17, 2008 at 12:22:29AM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Introduce 'struct pm_ops' representing a set of suspend and
> hibernation operations for bus types, device classes and device
> types.

Ok, I must have missed the thread describing why we need to do this, so,
why do we need to do this?  What is this going to buy us in the end
after everything is changed?

> +struct pm_ops {
> +#ifdef CONFIG_PM_SLEEP
> +	int (*prepare)(struct device *dev);
> +	void (*complete)(struct device *dev);
> +#endif
> +#ifdef CONFIG_SUSPEND
> +	int (*suspend)(struct device *dev);
> +	int (*resume)(struct device *dev);
> +#endif
> +#ifdef CONFIG_HIBERNATION
> +	int (*freeze)(struct device *dev);
> +	int (*thaw)(struct device *dev);
> +	int (*poweroff)(struct device *dev);
> +	int (*quiesce)(struct device *dev);
> +	int (*restore)(struct device *dev);
> +	int (*recover)(struct device *dev);
> +#endif


Don't ifdef stuff like this, it only causes ifdefs to be needed to the
.c code as well for all places these structures are defined in
drivers/busses, right?

thanks,

greg k-h

Re: [RFC][PATCH 3/3] PM: New suspend and hibernation callbacks for PCI bus type

[Greg KH]

On Mon, Mar 17, 2008 at 12:25:15AM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Implement new suspend and hibernation callbacks for the PCI busi type.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/pci/pci-driver.c |  497 ++++++++++++++++++++++++++++++++++++++++++-----
>  include/linux/pci.h      |    2 
>  2 files changed, 453 insertions(+), 46 deletions(-)

Hm, that's a lot of code added.  What additional functionality did we
just get?

Are we going to have to create a noirq version for every driver and bus
type now?

thanks,

greg k-h

Re: [RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks

[Pavel Machek]

On Tue 2008-03-18 17:53:40, Greg KH wrote:
> On Mon, Mar 17, 2008 at 12:22:29AM +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> > 
> > Introduce 'struct pm_ops' representing a set of suspend and
> > hibernation operations for bus types, device classes and device
> > types.
> 
> Ok, I must have missed the thread describing why we need to do this, so,
> why do we need to do this?  What is this going to buy us in the end
> after everything is changed?

That was rather long thread where Linus flamed us for having
everything in one "suspend" callback, selecting what to do by
pm_message_t parameter. It was kind of hard to miss ;-).
								Pavel


> > +struct pm_ops {
> > +#ifdef CONFIG_PM_SLEEP
> > +	int (*prepare)(struct device *dev);
> > +	void (*complete)(struct device *dev);
> > +#endif
> > +#ifdef CONFIG_SUSPEND
> > +	int (*suspend)(struct device *dev);
> > +	int (*resume)(struct device *dev);
> > +#endif
> > +#ifdef CONFIG_HIBERNATION
> > +	int (*freeze)(struct device *dev);
> > +	int (*thaw)(struct device *dev);
> > +	int (*poweroff)(struct device *dev);
> > +	int (*quiesce)(struct device *dev);
> > +	int (*restore)(struct device *dev);
> > +	int (*recover)(struct device *dev);
> > +#endif
> 
> 
> Don't ifdef stuff like this, it only causes ifdefs to be needed to the
> .c code as well for all places these structures are defined in
> drivers/busses, right?

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
pomozte zachranit klanovicky les:  http://www.ujezdskystrom.info/

Re: [RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks

[Rafael J. Wysocki]

On Wednesday, 19 of March 2008, Greg KH wrote:
> On Mon, Mar 17, 2008 at 12:22:29AM +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> > 
> > Introduce 'struct pm_ops' representing a set of suspend and
> > hibernation operations for bus types, device classes and device
> > types.
> 
> Ok, I must have missed the thread describing why we need to do this, so,
> why do we need to do this?  What is this going to buy us in the end
> after everything is changed?

There were many threads related to that.

To summarize, the first purpose is to separate suspend (aka s2ram and standby)
callbacks from hibernation callbacks in such a way that the new callbacks won't
take arguments and the purpose of each of them will be clearly specified.  This
has been requested multiple times by many people, including Linus himself,
and the reason is that within the current scheme if ->resume() is called, for
example, it's difficult to say why it's been called (ie. is it a resume from RAM or
from hibernation or a suspend/hibernation failure etc.?).

The second purpose is to make the suspend/hibernation callbacks more flexible
so that device drivers can handle more than they can within the current scheme.
For example, some drivers may need to prevent new children of the device from
being registered before their ->suspend() callbacks are executed or they may
want to carry out some operations requiring the availability of some other
devices, not directly bound via the parent-child relationship, in order to prepare
for the execution of ->suspend(), etc.

Ultimately, we'd like to stop using the freezing of tasks for suspend and
therefore the drivers' suspend/hibernation code will have to take care of
the handling of the user space during suspend/hibernation which would be
difficult within the current scheme, without the ->prepare() and ->complete()
callbacks.

> > +struct pm_ops {
> > +#ifdef CONFIG_PM_SLEEP
> > +	int (*prepare)(struct device *dev);
> > +	void (*complete)(struct device *dev);
> > +#endif
> > +#ifdef CONFIG_SUSPEND
> > +	int (*suspend)(struct device *dev);
> > +	int (*resume)(struct device *dev);
> > +#endif
> > +#ifdef CONFIG_HIBERNATION
> > +	int (*freeze)(struct device *dev);
> > +	int (*thaw)(struct device *dev);
> > +	int (*poweroff)(struct device *dev);
> > +	int (*quiesce)(struct device *dev);
> > +	int (*restore)(struct device *dev);
> > +	int (*recover)(struct device *dev);
> > +#endif
> 
> 
> Don't ifdef stuff like this, it only causes ifdefs to be needed to the
> .c code as well for all places these structures are defined in
> drivers/busses, right?

Sure, but that code won't be necessary otherwise too.

I'll remove the #ifdefs in the next version of the patch.

Thanks,
Rafael

Re: [RFC][PATCH 3/3] PM: New suspend and hibernation callbacks for PCI bus type

[Rafael J. Wysocki]

On Wednesday, 19 of March 2008, Greg KH wrote:
> On Mon, Mar 17, 2008 at 12:25:15AM +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> > 
> > Implement new suspend and hibernation callbacks for the PCI busi type.
> > 
> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > ---
> >  drivers/pci/pci-driver.c |  497 ++++++++++++++++++++++++++++++++++++++++++-----
> >  include/linux/pci.h      |    2 
> >  2 files changed, 453 insertions(+), 46 deletions(-)
> 
> Hm, that's a lot of code added.  What additional functionality did we
> just get?

The possibility to handle suspend/hibernation in a more flexible way, provided
that the drivers define the new callbacks.

> Are we going to have to create a noirq version for every driver and bus
> type now?

No, we aren't.  The PCI and platform bus types already have the noirq callbacks
implemented (they are called _late and _early, but that's the same
essentially).

Thanks,
Rafael

Re: [RFC][PATCH 3/3] PM: New suspend and hibernation callbacks for PCI bus type

[Greg KH]

On Wed, Mar 19, 2008 at 02:24:48PM +0100, Rafael J. Wysocki wrote:
> On Wednesday, 19 of March 2008, Greg KH wrote:
> > On Mon, Mar 17, 2008 at 12:25:15AM +0100, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rjw@sisk.pl>
> > > 
> > > Implement new suspend and hibernation callbacks for the PCI busi type.
> > > 
> > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> > > ---
> > >  drivers/pci/pci-driver.c |  497 ++++++++++++++++++++++++++++++++++++++++++-----
> > >  include/linux/pci.h      |    2 
> > >  2 files changed, 453 insertions(+), 46 deletions(-)
> > 
> > Hm, that's a lot of code added.  What additional functionality did we
> > just get?
> 
> The possibility to handle suspend/hibernation in a more flexible way, provided
> that the drivers define the new callbacks.

So, we're going to have to now convert all drivers, right?  Nice, I can
always use a bump up in the "number of patches submited" numbers :)

thanks,

greg k-h

Re: [RFC][PATCH 1/3] PM: Introduce new top level suspend and hibernation callbacks

[Greg KH]

On Wed, Mar 19, 2008 at 02:22:00PM +0100, Rafael J. Wysocki wrote:
> On Wednesday, 19 of March 2008, Greg KH wrote:
> > On Mon, Mar 17, 2008 at 12:22:29AM +0100, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rjw@sisk.pl>
> > > 
> > > Introduce 'struct pm_ops' representing a set of suspend and
> > > hibernation operations for bus types, device classes and device
> > > types.
> > 
> > Ok, I must have missed the thread describing why we need to do this, so,
> > why do we need to do this?  What is this going to buy us in the end
> > after everything is changed?
> 
> There were many threads related to that.
> 
> To summarize, the first purpose is to separate suspend (aka s2ram and standby)
> callbacks from hibernation callbacks in such a way that the new callbacks won't
> take arguments and the purpose of each of them will be clearly specified.  This
> has been requested multiple times by many people, including Linus himself,
> and the reason is that within the current scheme if ->resume() is called, for
> example, it's difficult to say why it's been called (ie. is it a resume from RAM or
> from hibernation or a suspend/hibernation failure etc.?).
> 
> The second purpose is to make the suspend/hibernation callbacks more flexible
> so that device drivers can handle more than they can within the current scheme.
> For example, some drivers may need to prevent new children of the device from
> being registered before their ->suspend() callbacks are executed or they may
> want to carry out some operations requiring the availability of some other
> devices, not directly bound via the parent-child relationship, in order to prepare
> for the execution of ->suspend(), etc.
> 
> Ultimately, we'd like to stop using the freezing of tasks for suspend and
> therefore the drivers' suspend/hibernation code will have to take care of
> the handling of the user space during suspend/hibernation which would be
> difficult within the current scheme, without the ->prepare() and ->complete()
> callbacks.

Ok, thanks.  You might want to include this in the patch itself (hint,
hint, hint...)

greg k-h