Hibernation: Introduce begin() and end() callbacks

Introduce global hibernation callback .end() and rename global
hibernation callback .start() to .begin(), in analogy with the
recent modifications of the global suspend callbacks.

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

3 files changed, 45 insertions, 16 deletions

diff --git a/drivers/acpi/sleep/main.c b/drivers/acpi/sleep/main.c
index c37c4ead95c9..31e8e58e1cec 100644
--- a/drivers/acpi/sleep/main.c
+++ b/drivers/acpi/sleep/main.c
@@ -281,7 +281,7 @@ static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
 #endif /* CONFIG_SUSPEND */
 
 #ifdef CONFIG_HIBERNATION
-static int acpi_hibernation_start(void)
+static int acpi_hibernation_begin(void)
 {
         acpi_target_sleep_state = ACPI_STATE_S4;
         return 0;
@@ -341,6 +341,15 @@ static void acpi_hibernation_finish(void)
         acpi_target_sleep_state = ACPI_STATE_S0;
 }
 
+static void acpi_hibernation_end(void)
+{
+        /*
+         * This is necessary in case acpi_hibernation_finish() is not called
+         * during a failing transition to the sleep state.
+         */
+        acpi_target_sleep_state = ACPI_STATE_S0;
+}
+
 static int acpi_hibernation_pre_restore(void)
 {
         acpi_status status;
@@ -356,7 +365,8 @@ static void acpi_hibernation_restore_cleanup(void)
 }
 
 static struct platform_hibernation_ops acpi_hibernation_ops = {
-        .start = acpi_hibernation_start,
+        .begin = acpi_hibernation_begin,
+        .end = acpi_hibernation_end,
         .pre_snapshot = acpi_hibernation_prepare,
         .finish = acpi_hibernation_finish,
         .prepare = acpi_hibernation_prepare,
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index a0b1dbb5919f..646ce2d068d4 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -136,14 +136,17 @@ extern void mark_free_pages(struct zone *zone);
 /**
  * struct platform_hibernation_ops - hibernation platform support
  *
- * The methods in this structure allow a platform to override the default
- * mechanism of shutting down the machine during a hibernation transition.
+ * The methods in this structure allow a platform to carry out special
+ * operations required by it during a hibernation transition.
  *
- * All three methods must be assigned.
+ * All the methods below must be implemented.
  *
- * @start: Tell the platform driver that we're starting hibernation.
+ * @begin: Tell the platform driver that we're starting hibernation.
  *      Called right after shrinking memory and before freezing devices.
  *
+ * @end: Called by the PM core right after resuming devices, to indicate to
+ *      the platform that the system has returned to the working state.
+ *
  * @pre_snapshot: Prepare the platform for creating the hibernation image.
  *      Called right after devices have been frozen and before the nonboot
  *      CPUs are disabled (runs with IRQs on).
@@ -178,7 +181,8 @@ extern void mark_free_pages(struct zone *zone);
  *      thawing devices (runs with IRQs on).
  */
 struct platform_hibernation_ops {
-        int (*start)(void);
+        int (*begin)(void);
+        void (*end)(void);
         int (*pre_snapshot)(void);
         void (*finish)(void);
         int (*prepare)(void);
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 64e42ab8b57c..53c22d9cf577 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -54,8 +54,8 @@ static struct platform_hibernation_ops *hibernation_ops;
 
 void hibernation_set_ops(struct platform_hibernation_ops *ops)
 {
-        if (ops && !(ops->start && ops->pre_snapshot && ops->finish
-            && ops->prepare && ops->enter && ops->pre_restore
+        if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
+            && ops->prepare && ops->finish && ops->enter && ops->pre_restore
             && ops->restore_cleanup)) {
                 WARN_ON(1);
                 return;
@@ -100,14 +100,25 @@ static int hibernation_test(int level) { return 0; }
 #endif /* !CONFIG_PM_DEBUG */
 
 /**
- *      platform_start - tell the platform driver that we're starting
+ *      platform_begin - tell the platform driver that we're starting
  *      hibernation
  */
 
-static int platform_start(int platform_mode)
+static int platform_begin(int platform_mode)
 {
         return (platform_mode && hibernation_ops) ?
-                hibernation_ops->start() : 0;
+                hibernation_ops->begin() : 0;
+}
+
+/**
+ *      platform_end - tell the platform driver that we've entered the
+ *      working state
+ */
+
+static void platform_end(int platform_mode)
+{
+        if (platform_mode && hibernation_ops)
+                hibernation_ops->end();
 }
 
 /**
@@ -237,9 +248,9 @@ int hibernation_snapshot(int platform_mode)
         if (error)
                 return error;
 
-        error = platform_start(platform_mode);
+        error = platform_begin(platform_mode);
         if (error)
-                return error;
+                goto Close;
 
         suspend_console();
         error = device_suspend(PMSG_FREEZE);
@@ -272,6 +283,8 @@ int hibernation_snapshot(int platform_mode)
         device_resume();
  Resume_console:
         resume_console();
+ Close:
+        platform_end(platform_mode);
         return error;
 }
 
@@ -373,9 +386,9 @@ int hibernation_platform_enter(void)
          * hibernation_ops->finish() before saving the image, so we should let
          * the firmware know that we're going to enter the sleep state after all
          */
-        error = hibernation_ops->start();
+        error = hibernation_ops->begin();
         if (error)
-                return error;
+                goto Close;
 
         suspend_console();
         error = device_suspend(PMSG_SUSPEND);
@@ -409,6 +422,8 @@ int hibernation_platform_enter(void)
         device_resume();
  Resume_console:
         resume_console();
+ Close:
+        hibernation_ops->end();
         return error;
 }