Suspend: Introduce begin() and end() callbacks

On ACPI systems the target state set by acpi_pm_set_target() is
reset by acpi_pm_finish(), but that need not be called if the
suspend fails.  All platforms that use the .set_target() global
suspend callback are affected by analogous issues.

For this reason, we need an additional global suspend callback that
will reset the target state regardless of whether or not the suspend
is successful.  Also, it is reasonable to rename the .set_target()
callback, since it will be used for a different purpose on ACPI
systems (due to ACPI 1.0x code ordering requirements).

Introduce the global suspend callback .end() to be executed at the
end of the suspend sequence and rename the .set_target() global
suspend callback to .begin().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/drivers/acpi/sleep/main.c b/drivers/acpi/sleep/main.c
index 96d23b3cfc4e..e2e4e617952b 100644
--- a/drivers/acpi/sleep/main.c
+++ b/drivers/acpi/sleep/main.c
@@ -63,11 +63,11 @@ static u32 acpi_suspend_states[] = {
 static int init_8259A_after_S1;
 
 /**
- *      acpi_pm_set_target - Set the target system sleep state to the state
+ *      acpi_pm_begin - Set the target system sleep state to the state
  *              associated with given @pm_state, if supported.
  */
 
-static int acpi_pm_set_target(suspend_state_t pm_state)
+static int acpi_pm_begin(suspend_state_t pm_state)
 {
         u32 acpi_state = acpi_suspend_states[pm_state];
         int error = 0;
@@ -164,7 +164,7 @@ static int acpi_pm_enter(suspend_state_t pm_state)
 }
 
 /**
- *      acpi_pm_finish - Finish up suspend sequence.
+ *      acpi_pm_finish - Instruct the platform to leave a sleep state.
  *
  *      This is called after we wake back up (or if entering the sleep state
  *      failed). 
@@ -190,6 +190,19 @@ static void acpi_pm_finish(void)
 #endif
 }
 
+/**
+ *      acpi_pm_end - Finish up suspend sequence.
+ */
+
+static void acpi_pm_end(void)
+{
+        /*
+         * This is necessary in case acpi_pm_finish() is not called during a
+         * failing transition to a sleep state.
+         */
+        acpi_target_sleep_state = ACPI_STATE_S0;
+}
+
 static int acpi_pm_state_valid(suspend_state_t pm_state)
 {
         u32 acpi_state;
@@ -208,10 +221,11 @@ static int acpi_pm_state_valid(suspend_state_t pm_state)
 
 static struct platform_suspend_ops acpi_pm_ops = {
         .valid = acpi_pm_state_valid,
-        .set_target = acpi_pm_set_target,
+        .begin = acpi_pm_begin,
         .prepare = acpi_pm_prepare,
         .enter = acpi_pm_enter,
         .finish = acpi_pm_finish,
+        .end = acpi_pm_end,
 };
 
 /*