PM: Introduce PM_EVENT_HIBERNATE callback state

During the last step of hibernation in the "platform" mode (with the
help of ACPI) we use the suspend code, including the devices'
->suspend() methods, to prepare the system for entering the ACPI S4
system sleep state.

But at least for some devices the operations performed by the
->suspend() callback in that case must be different from its operations
during regular suspend.

For this reason, introduce the new PM event type PM_EVENT_HIBERNATE and
pass it to the device drivers' ->suspend() methods during the last phase
of hibernation, so that they can distinguish this case and handle it as
appropriate.  Modify the drivers that handle PM_EVENT_SUSPEND in a
special way and need to handle PM_EVENT_HIBERNATE in the same way.

These changes are necessary to fix a hibernation regression related
to the i915 driver (ref. http://lkml.org/lkml/2008/2/22/488).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/power/devices.txt

@@ -310,9 +310,12 @@ used with suspend-to-disk:
     PM_EVENT_SUSPEND -- quiesce the driver and put hardware into a low-power
 	state.  When used with system sleep states like "suspend-to-RAM" or
 	"standby", the upcoming resume() call will often be able to rely on
-	state kept in hardware, or issue system wakeup events.  When used
-	instead with suspend-to-disk, few devices support this capability;
-	most are completely powered off.
+	state kept in hardware, or issue system wakeup events.
+
+    PM_EVENT_HIBERNATE -- Put hardware into a low-power state and enable wakeup
+	events as appropriate.  It is only used with hibernation
+	(suspend-to-disk) and few devices are able to wake up the system from
+	this state; most are completely powered off.
 
     PM_EVENT_FREEZE -- quiesce the driver, but don't necessarily change into
 	any low power mode.  A system snapshot is about to be taken, often
@@ -329,8 +332,8 @@ used with suspend-to-disk:
 	wakeup events nor DMA are allowed.
 
 To enter "standby" (ACPI S1) or "Suspend to RAM" (STR, ACPI S3) states, or
-the similarly named APM states, only PM_EVENT_SUSPEND is used; for "Suspend
-to Disk" (STD, hibernate, ACPI S4), all of those event codes are used.
+the similarly named APM states, only PM_EVENT_SUSPEND is used; the other event
+codes are used for hibernation ("Suspend to Disk", STD, ACPI S4).
 
 There's also PM_EVENT_ON, a value which never appears as a suspend event
 but is sometimes used to record the "not suspended" device state.

drivers/ata/ahci.c

@@ -1932,7 +1932,7 @@ static int ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
 	void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
 	u32 ctl;
 
-	if (mesg.event == PM_EVENT_SUSPEND) {
+	if (mesg.event & PM_EVENT_SLEEP) {
 		/* AHCI spec rev1.1 section 8.3.3:
 		 * Software must disable interrupts prior to requesting a
 		 * transition of the HBA to D3 state.

drivers/ata/ata_piix.c

@@ -1339,7 +1339,7 @@ static int piix_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
 	 * cycles and power trying to do something to the sleeping
 	 * beauty.
 	 */
-	if (piix_broken_suspend() && mesg.event == PM_EVENT_SUSPEND) {
+	if (piix_broken_suspend() && (mesg.event & PM_EVENT_SLEEP)) {
 		pci_save_state(pdev);
 
 		/* mark its power state as "unknown", since we don't

drivers/ata/libata-core.c

@@ -7368,7 +7368,7 @@ void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
 	pci_save_state(pdev);
 	pci_disable_device(pdev);
 
-	if (mesg.event == PM_EVENT_SUSPEND)
+	if (mesg.event & PM_EVENT_SLEEP)
 		pci_set_power_state(pdev, PCI_D3hot);
 }
 

drivers/ide/ppc/pmac.c

@@ -1254,7 +1254,7 @@ pmac_ide_macio_suspend(struct macio_dev *mdev, pm_message_t mesg)
 	int		rc = 0;
 
 	if (mesg.event != mdev->ofdev.dev.power.power_state.event
-			&& mesg.event == PM_EVENT_SUSPEND) {
+			&& (mesg.event & PM_EVENT_SLEEP)) {
 		rc = pmac_ide_do_suspend(hwif);
 		if (rc == 0)
 			mdev->ofdev.dev.power.power_state = mesg;
@@ -1364,7 +1364,7 @@ pmac_ide_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
 	int		rc = 0;
 	
 	if (mesg.event != pdev->dev.power.power_state.event
-			&& mesg.event == PM_EVENT_SUSPEND) {
+			&& (mesg.event & PM_EVENT_SLEEP)) {
 		rc = pmac_ide_do_suspend(hwif);
 		if (rc == 0)
 			pdev->dev.power.power_state = mesg;

drivers/macintosh/mediabay.c

@@ -698,7 +698,8 @@ static int media_bay_suspend(struct macio_dev *mdev, pm_message_t state)
 {
 	struct media_bay_info	*bay = macio_get_drvdata(mdev);
 
-	if (state.event != mdev->ofdev.dev.power.power_state.event && state.event == PM_EVENT_SUSPEND) {
+	if (state.event != mdev->ofdev.dev.power.power_state.event
+	    && (state.event & PM_EVENT_SLEEP)) {
 		down(&bay->lock);
 		bay->sleeping = 1;
 		set_mb_power(bay, 0);

drivers/pci/pci.c

@@ -554,6 +554,7 @@ pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
 	case PM_EVENT_PRETHAW:
 		/* REVISIT both freeze and pre-thaw "should" use D0 */
 	case PM_EVENT_SUSPEND:
+	case PM_EVENT_HIBERNATE:
 		return PCI_D3hot;
 	default:
 		printk("Unrecognized suspend event %d\n", state.event);

drivers/scsi/aic7xxx/aic79xx_osm_pci.c

@@ -89,7 +89,7 @@ ahd_linux_pci_dev_suspend(struct pci_dev *pdev, pm_message_t mesg)
 	pci_save_state(pdev);
 	pci_disable_device(pdev);
 
-	if (mesg.event == PM_EVENT_SUSPEND)
+	if (mesg.event & PM_EVENT_SLEEP)
 		pci_set_power_state(pdev, PCI_D3hot);
 
 	return rc;

drivers/scsi/aic7xxx/aic7xxx_osm_pci.c

@@ -134,7 +134,7 @@ ahc_linux_pci_dev_suspend(struct pci_dev *pdev, pm_message_t mesg)
 	pci_save_state(pdev);
 	pci_disable_device(pdev);
 
-	if (mesg.event == PM_EVENT_SUSPEND)
+	if (mesg.event & PM_EVENT_SLEEP)
 		pci_set_power_state(pdev, PCI_D3hot);
 
 	return rc;

drivers/scsi/mesh.c

@@ -1759,6 +1759,7 @@ static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
 
 	switch (mesg.event) {
 	case PM_EVENT_SUSPEND:
+	case PM_EVENT_HIBERNATE:
 	case PM_EVENT_FREEZE:
 		break;
 	default:

drivers/scsi/sd.c

@@ -1835,8 +1835,7 @@ static int sd_suspend(struct device *dev, pm_message_t mesg)
 			goto done;
 	}
 
-	if (mesg.event == PM_EVENT_SUSPEND &&
-	    sdkp->device->manage_start_stop) {
+	if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
 		ret = sd_start_stop_device(sdkp, 0);
 	}

drivers/usb/host/sl811-hcd.c

@@ -1766,6 +1766,7 @@ sl811h_suspend(struct platform_device *dev, pm_message_t state)
 		retval = sl811h_bus_suspend(hcd);
 		break;
 	case PM_EVENT_SUSPEND:
+	case PM_EVENT_HIBERNATE:
 	case PM_EVENT_PRETHAW:		/* explicitly discard hw state */
 		port_power(sl811, 0);
 		break;

drivers/usb/host/u132-hcd.c

@@ -3214,14 +3214,19 @@ static int u132_suspend(struct platform_device *pdev, pm_message_t state)
                 return -ESHUTDOWN;
         } else {
                 int retval = 0;
-                if (state.event == PM_EVENT_FREEZE) {
+
+		switch (state.event) {
+		case PM_EVENT_FREEZE:
                         retval = u132_bus_suspend(hcd);
-                } else if (state.event == PM_EVENT_SUSPEND) {
+			break;
+		case PM_EVENT_SUSPEND:
+		case PM_EVENT_HIBERNATE:
                         int ports = MAX_U132_PORTS;
                         while (ports-- > 0) {
                                 port_power(u132, ports, 0);
                         }
-                }
+			break;
+		}
                 if (retval == 0)
                         pdev->dev.power.power_state = state;
                 return retval;

drivers/video/chipsfb.c

@@ -459,7 +459,7 @@ static int chipsfb_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	if (state.event == pdev->dev.power.power_state.event)
 		return 0;
-	if (state.event != PM_EVENT_SUSPEND)
+	if (!(state.event & PM_EVENT_SLEEP))
 		goto done;
 
 	acquire_console_sem();

drivers/video/nvidia/nvidia.c

@@ -1066,7 +1066,7 @@ static int nvidiafb_suspend(struct pci_dev *dev, pm_message_t mesg)
 	acquire_console_sem();
 	par->pm_state = mesg.event;
 
-	if (mesg.event == PM_EVENT_SUSPEND) {
+	if (mesg.event & PM_EVENT_SLEEP) {
 		fb_set_suspend(info, 1);
 		nvidiafb_blank(FB_BLANK_POWERDOWN, info);
 		nvidia_write_regs(par, &par->SavedReg);

include/linux/pm.h

@@ -143,6 +143,9 @@ typedef struct pm_message {
  * 		the upcoming system state (such as PCI_D3hot), and enable
  * 		wakeup events as appropriate.
  *
+ * HIBERNATE	Enter a low power device state appropriate for the hibernation
+ * 		state (eg. ACPI S4) and enable wakeup events as appropriate.
+ *
  * FREEZE	Quiesce operations so that a consistent image can be saved;
  * 		but do NOT otherwise enter a low power device state, and do
  * 		NOT emit system wakeup events.
@@ -166,11 +169,15 @@ typedef struct pm_message {
 #define PM_EVENT_ON 0
 #define PM_EVENT_FREEZE 1
 #define PM_EVENT_SUSPEND 2
-#define PM_EVENT_PRETHAW 3
+#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 {

kernel/power/disk.c

@@ -391,7 +391,7 @@ int hibernation_platform_enter(void)
 		goto Close;
 
 	suspend_console();
-	error = device_suspend(PMSG_SUSPEND);
+	error = device_suspend(PMSG_HIBERNATE);
 	if (error)
 		goto Resume_console;
 
@@ -404,7 +404,7 @@ int hibernation_platform_enter(void)
 		goto Finish;
 
 	local_irq_disable();
-	error = device_power_down(PMSG_SUSPEND);
+	error = device_power_down(PMSG_HIBERNATE);
 	if (!error) {
 		hibernation_ops->enter();
 		/* We should never get here */

net/rfkill/rfkill.c

@@ -232,7 +232,7 @@ static int rfkill_suspend(struct device *dev, pm_message_t state)
 	struct rfkill *rfkill = to_rfkill(dev);
 
 	if (dev->power.power_state.event != state.event) {
-		if (state.event == PM_EVENT_SUSPEND) {
+		if (state.event & PM_EVENT_SLEEP) {
 			mutex_lock(&rfkill->mutex);
 
 			if (rfkill->state == RFKILL_STATE_ON)