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>

2 files changed, 9 insertions, 3 deletions

diff --git a/drivers/usb/host/sl811-hcd.c b/drivers/usb/host/sl811-hcd.c
index ba370c56172c..59be276ccd9d 100644
--- a/drivers/usb/host/sl811-hcd.c
+++ b/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;
diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
index ac283b09a63f..6fca06961559 100644
--- a/drivers/usb/host/u132-hcd.c
+++ b/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;