PM: introduce set_target method in pm_ops

Commit 52ade9b3b97fd3bea42842a056fe0786c28d0555 changed the suspend code
ordering to execute pm_ops->prepare() after the device model per-device
.suspend() calls in order to fix some ACPI-related issues.  Unfortunately, it
broke the at91 platform which assumed that pm_ops->prepare() would be called
before suspending devices.

at91 used pm_ops->prepare() to get notified of the target system sleep state,
so that it could use this information while suspending devices.  However, with
the current suspend code ordering pm_ops->prepare() is called too late for
this purpose.  Thus, at91 needs an additional method in 'struct pm_ops' that
will be used for notifying the platform of the target system sleep state.
Moreover, in the future such a method will also be needed by ACPI.

This patch adds the .set_target() method to 'struct pm_ops' and makes the
suspend code call it, if implemented, before executing the device model
per-device .suspend() calls.  It also modifies the at91 code to use
pm_ops->set_target() instead of pm_ops->prepare().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 47ff676aca5f..ddf9184d561d 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -53,7 +53,7 @@ static suspend_state_t target_state;
 /*
  * Called after processes are frozen, but before we shutdown devices.
  */
-static int at91_pm_prepare(suspend_state_t state)
+static int at91_pm_set_target(suspend_state_t state)
 {
         target_state = state;
         return 0;
@@ -201,7 +201,7 @@ error:
 
 static struct pm_ops at91_pm_ops ={
         .valid          = at91_pm_valid_state,
-        .prepare        = at91_pm_prepare,
+        .set_target     = at91_pm_set_target,
         .enter          = at91_pm_enter,
 };