1 files changed, 48 insertions, 1 deletions

diff --git a/drivers/acpi/sleep/main.c b/drivers/acpi/sleep/main.c
index d13194a031bf..c7f0c9cd8701 100644
--- a/drivers/acpi/sleep/main.c
+++ b/drivers/acpi/sleep/main.c
@@ -15,6 +15,7 @@
 #include <linux/dmi.h>
 #include <linux/device.h>
 #include <linux/suspend.h>
+#include <linux/reboot.h>
 
 #include <asm/io.h>
 
@@ -24,6 +25,36 @@
 
 u8 sleep_states[ACPI_S_STATE_COUNT];
 
+static void acpi_sleep_tts_switch(u32 acpi_state)
+{
+        union acpi_object in_arg = { ACPI_TYPE_INTEGER };
+        struct acpi_object_list arg_list = { 1, &in_arg };
+        acpi_status status = AE_OK;
+
+        in_arg.integer.value = acpi_state;
+        status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
+        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+                /*
+                 * OS can't evaluate the _TTS object correctly. Some warning
+                 * message will be printed. But it won't break anything.
+                 */
+                printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
+        }
+}
+
+static int tts_notify_reboot(struct notifier_block *this,
+                        unsigned long code, void *x)
+{
+        acpi_sleep_tts_switch(ACPI_STATE_S5);
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block tts_notifier = {
+        .notifier_call  = tts_notify_reboot,
+        .next           = NULL,
+        .priority       = 0,
+};
+
 static int acpi_sleep_prepare(u32 acpi_state)
 {
 #ifdef CONFIG_ACPI_SLEEP
@@ -131,6 +162,7 @@ static void acpi_pm_end(void)
          * failing transition to a sleep state.
          */
         acpi_target_sleep_state = ACPI_STATE_S0;
+        acpi_sleep_tts_switch(acpi_target_sleep_state);
 }
 #endif /* CONFIG_PM_SLEEP */
 
@@ -155,6 +187,7 @@ static int acpi_suspend_begin(suspend_state_t pm_state)
 
         if (sleep_states[acpi_state]) {
                 acpi_target_sleep_state = acpi_state;
+                acpi_sleep_tts_switch(acpi_target_sleep_state);
         } else {
                 printk(KERN_ERR "ACPI does not support this state: %d\n",
                         pm_state);
@@ -313,6 +346,7 @@ void __init acpi_no_s4_hw_signature(void)
 static int acpi_hibernation_begin(void)
 {
         acpi_target_sleep_state = ACPI_STATE_S4;
+        acpi_sleep_tts_switch(acpi_target_sleep_state);
         return 0;
 }
 
@@ -376,7 +410,15 @@ static struct platform_hibernation_ops acpi_hibernation_ops = {
  */
 static int acpi_hibernation_begin_old(void)
 {
-        int error = acpi_sleep_prepare(ACPI_STATE_S4);
+        int error;
+        /*
+         * The _TTS object should always be evaluated before the _PTS object.
+         * When the old_suspended_ordering is true, the _PTS object is
+         * evaluated in the acpi_sleep_prepare.
+         */
+        acpi_sleep_tts_switch(ACPI_STATE_S4);
+
+        error = acpi_sleep_prepare(ACPI_STATE_S4);
 
         if (!error)
                 acpi_target_sleep_state = ACPI_STATE_S4;
@@ -596,5 +638,10 @@ int __init acpi_sleep_init(void)
                 pm_power_off = acpi_power_off;
         }
         printk(")\n");
+        /*
+         * Register the tts_notifier to reboot notifier list so that the _TTS
+         * object can also be evaluated when the system enters S5.
+         */
+        register_reboot_notifier(&tts_notifier);
         return 0;
 }