PM: no suspend_prepare() phase

Remove the new suspend_prepare() phase.  It doesn't seem very usable,
has never been tested, doesn't address fault cleanup, and would need
a sibling resume_complete(); plus there are no real use cases.  It
could be restored later if those issues get resolved.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base/power/suspend.c

@@ -117,33 +117,6 @@ static int suspend_device_late(struct device *dev, pm_message_t state)
 	return error;
 }
 
-/**
- *	device_prepare_suspend - save state and prepare to suspend
- *
- *	NOTE! Devices cannot detach at this point - not only do we
- *	hold the device list semaphores over the whole prepare, but
- *	the whole point is to do non-invasive preparatory work, not
- *	the actual suspend.
- */
-int device_prepare_suspend(pm_message_t state)
-{
-	int error = 0;
-	struct device * dev;
-
-	down(&dpm_sem);
-	down(&dpm_list_sem);
-	list_for_each_entry_reverse(dev, &dpm_active, power.entry) {
-		if (!dev->bus || !dev->bus->suspend_prepare)
-			continue;
-		error = dev->bus->suspend_prepare(dev, state);
-		if (error)
-			break;
-	}
-	up(&dpm_list_sem);
-	up(&dpm_sem);
-	return error;
-}
-
 /**
  *	device_suspend - Save state and stop all devices in system.
  *	@state:		Power state to put each device in.

drivers/pci/pci-driver.c

@@ -264,19 +264,6 @@ static int pci_device_remove(struct device * dev)
 	return 0;
 }
 
-static int pci_device_suspend_prepare(struct device * dev, pm_message_t state)
-{
-	struct pci_dev * pci_dev = to_pci_dev(dev);
-	struct pci_driver * drv = pci_dev->driver;
-	int i = 0;
-
-	if (drv && drv->suspend_prepare) {
-		i = drv->suspend_prepare(pci_dev, state);
-		suspend_report_result(drv->suspend_prepare, i);
-	}
-	return i;
-}
-
 static int pci_device_suspend(struct device * dev, pm_message_t state)
 {
 	struct pci_dev * pci_dev = to_pci_dev(dev);
@@ -544,7 +531,6 @@ struct bus_type pci_bus_type = {
 	.uevent		= pci_uevent,
 	.probe		= pci_device_probe,
 	.remove		= pci_device_remove,
-	.suspend_prepare= pci_device_suspend_prepare,
 	.suspend	= pci_device_suspend,
 	.suspend_late	= pci_device_suspend_late,
 	.resume_early	= pci_device_resume_early,

include/linux/device.h

@@ -52,7 +52,6 @@ struct bus_type {
 	int		(*remove)(struct device * dev);
 	void		(*shutdown)(struct device * dev);
 
-	int (*suspend_prepare)(struct device * dev, pm_message_t state);
 	int (*suspend)(struct device * dev, pm_message_t state);
 	int (*suspend_late)(struct device * dev, pm_message_t state);
 	int (*resume_early)(struct device * dev);

include/linux/pci.h

@@ -345,7 +345,6 @@ struct pci_driver {
 	const struct pci_device_id *id_table;	/* must be non-NULL for probe to be called */
 	int  (*probe)  (struct pci_dev *dev, const struct pci_device_id *id);	/* New device inserted */
 	void (*remove) (struct pci_dev *dev);	/* Device removed (NULL if not a hot-plug capable driver) */
-	int  (*suspend_prepare) (struct pci_dev *dev, pm_message_t state);
 	int  (*suspend) (struct pci_dev *dev, pm_message_t state);	/* Device suspended */
 	int  (*suspend_late) (struct pci_dev *dev, pm_message_t state);
 	int  (*resume_early) (struct pci_dev *dev);

kernel/power/main.c

@@ -57,10 +57,6 @@ static int suspend_prepare(suspend_state_t state)
 	if (!pm_ops || !pm_ops->enter)
 		return -EPERM;
 
-	error = device_prepare_suspend(PMSG_SUSPEND);
-	if (error)
-		return error;
-
 	pm_prepare_console();
 
 	disable_nonboot_cpus();