2 * sleep.c - ACPI sleep support.
4 * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
5 * Copyright (c) 2004 David Shaohua Li <shaohua.li@intel.com>
6 * Copyright (c) 2000-2003 Patrick Mochel
7 * Copyright (c) 2003 Open Source Development Lab
9 * This file is released under the GPLv2.
13 #include <linux/delay.h>
14 #include <linux/irq.h>
15 #include <linux/dmi.h>
16 #include <linux/device.h>
17 #include <linux/suspend.h>
18 #include <linux/reboot.h>
19 #include <linux/acpi.h>
23 #include <acpi/acpi_bus.h>
24 #include <acpi/acpi_drivers.h>
29 static u8 sleep_states
[ACPI_S_STATE_COUNT
];
31 static void acpi_sleep_tts_switch(u32 acpi_state
)
33 union acpi_object in_arg
= { ACPI_TYPE_INTEGER
};
34 struct acpi_object_list arg_list
= { 1, &in_arg
};
35 acpi_status status
= AE_OK
;
37 in_arg
.integer
.value
= acpi_state
;
38 status
= acpi_evaluate_object(NULL
, "\\_TTS", &arg_list
, NULL
);
39 if (ACPI_FAILURE(status
) && status
!= AE_NOT_FOUND
) {
41 * OS can't evaluate the _TTS object correctly. Some warning
42 * message will be printed. But it won't break anything.
44 printk(KERN_NOTICE
"Failure in evaluating _TTS object\n");
48 static int tts_notify_reboot(struct notifier_block
*this,
49 unsigned long code
, void *x
)
51 acpi_sleep_tts_switch(ACPI_STATE_S5
);
55 static struct notifier_block tts_notifier
= {
56 .notifier_call
= tts_notify_reboot
,
61 static int acpi_sleep_prepare(u32 acpi_state
)
63 #ifdef CONFIG_ACPI_SLEEP
64 /* do we have a wakeup address for S2 and S3? */
65 if (acpi_state
== ACPI_STATE_S3
) {
66 if (!acpi_wakeup_address
) {
69 acpi_set_firmware_waking_vector(
70 (acpi_physical_address
)acpi_wakeup_address
);
73 ACPI_FLUSH_CPU_CACHE();
75 printk(KERN_INFO PREFIX
"Preparing to enter system sleep state S%d\n",
77 acpi_enable_wakeup_devices(acpi_state
);
78 acpi_enter_sleep_state_prep(acpi_state
);
82 #ifdef CONFIG_ACPI_SLEEP
83 static u32 acpi_target_sleep_state
= ACPI_STATE_S0
;
86 * The ACPI specification wants us to save NVS memory regions during hibernation
87 * and to restore them during the subsequent resume. Windows does that also for
88 * suspend to RAM. However, it is known that this mechanism does not work on
89 * all machines, so we allow the user to disable it with the help of the
90 * 'acpi_sleep=nonvs' kernel command line option.
92 static bool nvs_nosave
;
94 void __init
acpi_nvs_nosave(void)
100 * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
101 * user to request that behavior by using the 'acpi_old_suspend_ordering'
102 * kernel command line option that causes the following variable to be set.
104 static bool old_suspend_ordering
;
106 void __init
acpi_old_suspend_ordering(void)
108 old_suspend_ordering
= true;
112 * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
114 static int acpi_pm_freeze(void)
116 acpi_disable_all_gpes();
117 acpi_os_wait_events_complete(NULL
);
118 acpi_ec_block_transactions();
123 * acpi_pre_suspend - Enable wakeup devices, "freeze" EC and save NVS.
125 static int acpi_pm_pre_suspend(void)
128 return suspend_nvs_save();
132 * __acpi_pm_prepare - Prepare the platform to enter the target state.
134 * If necessary, set the firmware waking vector and do arch-specific
135 * nastiness to get the wakeup code to the waking vector.
137 static int __acpi_pm_prepare(void)
139 int error
= acpi_sleep_prepare(acpi_target_sleep_state
);
141 acpi_target_sleep_state
= ACPI_STATE_S0
;
147 * acpi_pm_prepare - Prepare the platform to enter the target sleep
148 * state and disable the GPEs.
150 static int acpi_pm_prepare(void)
152 int error
= __acpi_pm_prepare();
154 error
= acpi_pm_pre_suspend();
160 * acpi_pm_finish - Instruct the platform to leave a sleep state.
162 * This is called after we wake back up (or if entering the sleep state
165 static void acpi_pm_finish(void)
167 u32 acpi_state
= acpi_target_sleep_state
;
169 acpi_ec_unblock_transactions();
172 if (acpi_state
== ACPI_STATE_S0
)
175 printk(KERN_INFO PREFIX
"Waking up from system sleep state S%d\n",
177 acpi_disable_wakeup_devices(acpi_state
);
178 acpi_leave_sleep_state(acpi_state
);
180 /* reset firmware waking vector */
181 acpi_set_firmware_waking_vector((acpi_physical_address
) 0);
183 acpi_target_sleep_state
= ACPI_STATE_S0
;
187 * acpi_pm_end - Finish up suspend sequence.
189 static void acpi_pm_end(void)
192 * This is necessary in case acpi_pm_finish() is not called during a
193 * failing transition to a sleep state.
195 acpi_target_sleep_state
= ACPI_STATE_S0
;
196 acpi_sleep_tts_switch(acpi_target_sleep_state
);
198 #else /* !CONFIG_ACPI_SLEEP */
199 #define acpi_target_sleep_state ACPI_STATE_S0
200 #endif /* CONFIG_ACPI_SLEEP */
202 #ifdef CONFIG_SUSPEND
203 extern void do_suspend_lowlevel(void);
205 static u32 acpi_suspend_states
[] = {
206 [PM_SUSPEND_ON
] = ACPI_STATE_S0
,
207 [PM_SUSPEND_STANDBY
] = ACPI_STATE_S1
,
208 [PM_SUSPEND_MEM
] = ACPI_STATE_S3
,
209 [PM_SUSPEND_MAX
] = ACPI_STATE_S5
213 * acpi_suspend_begin - Set the target system sleep state to the state
214 * associated with given @pm_state, if supported.
216 static int acpi_suspend_begin(suspend_state_t pm_state
)
218 u32 acpi_state
= acpi_suspend_states
[pm_state
];
221 error
= nvs_nosave
? 0 : suspend_nvs_alloc();
225 if (sleep_states
[acpi_state
]) {
226 acpi_target_sleep_state
= acpi_state
;
227 acpi_sleep_tts_switch(acpi_target_sleep_state
);
229 printk(KERN_ERR
"ACPI does not support this state: %d\n",
237 * acpi_suspend_enter - Actually enter a sleep state.
240 * Flush caches and go to sleep. For STR we have to call arch-specific
241 * assembly, which in turn call acpi_enter_sleep_state().
242 * It's unfortunate, but it works. Please fix if you're feeling frisky.
244 static int acpi_suspend_enter(suspend_state_t pm_state
)
246 acpi_status status
= AE_OK
;
247 unsigned long flags
= 0;
248 u32 acpi_state
= acpi_target_sleep_state
;
250 ACPI_FLUSH_CPU_CACHE();
252 /* Do arch specific saving of state. */
253 if (acpi_state
== ACPI_STATE_S3
) {
254 int error
= acpi_save_state_mem();
260 local_irq_save(flags
);
261 switch (acpi_state
) {
264 status
= acpi_enter_sleep_state(acpi_state
);
268 do_suspend_lowlevel();
272 /* This violates the spec but is required for bug compatibility. */
273 acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE
, 1);
275 /* Reprogram control registers and execute _BFS */
276 acpi_leave_sleep_state_prep(acpi_state
);
278 /* ACPI 3.0 specs (P62) says that it's the responsibility
279 * of the OSPM to clear the status bit [ implying that the
280 * POWER_BUTTON event should not reach userspace ]
282 if (ACPI_SUCCESS(status
) && (acpi_state
== ACPI_STATE_S3
))
283 acpi_clear_event(ACPI_EVENT_POWER_BUTTON
);
286 * Disable and clear GPE status before interrupt is enabled. Some GPEs
287 * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
288 * acpi_leave_sleep_state will reenable specific GPEs later
290 acpi_disable_all_gpes();
291 /* Allow EC transactions to happen. */
292 acpi_ec_unblock_transactions_early();
294 local_irq_restore(flags
);
295 printk(KERN_DEBUG
"Back to C!\n");
297 /* restore processor state */
298 if (acpi_state
== ACPI_STATE_S3
)
299 acpi_restore_state_mem();
301 suspend_nvs_restore();
303 return ACPI_SUCCESS(status
) ? 0 : -EFAULT
;
306 static int acpi_suspend_state_valid(suspend_state_t pm_state
)
312 case PM_SUSPEND_STANDBY
:
314 acpi_state
= acpi_suspend_states
[pm_state
];
316 return sleep_states
[acpi_state
];
322 static const struct platform_suspend_ops acpi_suspend_ops
= {
323 .valid
= acpi_suspend_state_valid
,
324 .begin
= acpi_suspend_begin
,
325 .prepare_late
= acpi_pm_prepare
,
326 .enter
= acpi_suspend_enter
,
327 .wake
= acpi_pm_finish
,
332 * acpi_suspend_begin_old - Set the target system sleep state to the
333 * state associated with given @pm_state, if supported, and
334 * execute the _PTS control method. This function is used if the
335 * pre-ACPI 2.0 suspend ordering has been requested.
337 static int acpi_suspend_begin_old(suspend_state_t pm_state
)
339 int error
= acpi_suspend_begin(pm_state
);
341 error
= __acpi_pm_prepare();
347 * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
350 static const struct platform_suspend_ops acpi_suspend_ops_old
= {
351 .valid
= acpi_suspend_state_valid
,
352 .begin
= acpi_suspend_begin_old
,
353 .prepare_late
= acpi_pm_pre_suspend
,
354 .enter
= acpi_suspend_enter
,
355 .wake
= acpi_pm_finish
,
357 .recover
= acpi_pm_finish
,
360 static int __init
init_old_suspend_ordering(const struct dmi_system_id
*d
)
362 old_suspend_ordering
= true;
366 static int __init
init_nvs_nosave(const struct dmi_system_id
*d
)
372 static struct dmi_system_id __initdata acpisleep_dmi_table
[] = {
374 .callback
= init_old_suspend_ordering
,
375 .ident
= "Abit KN9 (nForce4 variant)",
377 DMI_MATCH(DMI_BOARD_VENDOR
, "http://www.abit.com.tw/"),
378 DMI_MATCH(DMI_BOARD_NAME
, "KN9 Series(NF-CK804)"),
382 .callback
= init_old_suspend_ordering
,
383 .ident
= "HP xw4600 Workstation",
385 DMI_MATCH(DMI_SYS_VENDOR
, "Hewlett-Packard"),
386 DMI_MATCH(DMI_PRODUCT_NAME
, "HP xw4600 Workstation"),
390 .callback
= init_old_suspend_ordering
,
391 .ident
= "Asus Pundit P1-AH2 (M2N8L motherboard)",
393 DMI_MATCH(DMI_BOARD_VENDOR
, "ASUSTek Computer INC."),
394 DMI_MATCH(DMI_BOARD_NAME
, "M2N8L"),
398 .callback
= init_old_suspend_ordering
,
399 .ident
= "Panasonic CF51-2L",
401 DMI_MATCH(DMI_BOARD_VENDOR
,
402 "Matsushita Electric Industrial Co.,Ltd."),
403 DMI_MATCH(DMI_BOARD_NAME
, "CF51-2L"),
407 .callback
= init_nvs_nosave
,
408 .ident
= "Sony Vaio VGN-SR11M",
410 DMI_MATCH(DMI_SYS_VENDOR
, "Sony Corporation"),
411 DMI_MATCH(DMI_PRODUCT_NAME
, "VGN-SR11M"),
415 .callback
= init_nvs_nosave
,
416 .ident
= "Everex StepNote Series",
418 DMI_MATCH(DMI_SYS_VENDOR
, "Everex Systems, Inc."),
419 DMI_MATCH(DMI_PRODUCT_NAME
, "Everex StepNote Series"),
423 .callback
= init_nvs_nosave
,
424 .ident
= "Sony Vaio VPCEB1Z1E",
426 DMI_MATCH(DMI_SYS_VENDOR
, "Sony Corporation"),
427 DMI_MATCH(DMI_PRODUCT_NAME
, "VPCEB1Z1E"),
431 .callback
= init_nvs_nosave
,
432 .ident
= "Sony Vaio VGN-NW130D",
434 DMI_MATCH(DMI_SYS_VENDOR
, "Sony Corporation"),
435 DMI_MATCH(DMI_PRODUCT_NAME
, "VGN-NW130D"),
439 .callback
= init_nvs_nosave
,
440 .ident
= "Averatec AV1020-ED2",
442 DMI_MATCH(DMI_SYS_VENDOR
, "AVERATEC"),
443 DMI_MATCH(DMI_PRODUCT_NAME
, "1000 Series"),
448 #endif /* CONFIG_SUSPEND */
450 #ifdef CONFIG_HIBERNATION
451 static unsigned long s4_hardware_signature
;
452 static struct acpi_table_facs
*facs
;
453 static bool nosigcheck
;
455 void __init
acpi_no_s4_hw_signature(void)
460 static int acpi_hibernation_begin(void)
464 error
= nvs_nosave
? 0 : suspend_nvs_alloc();
466 acpi_target_sleep_state
= ACPI_STATE_S4
;
467 acpi_sleep_tts_switch(acpi_target_sleep_state
);
473 static int acpi_hibernation_enter(void)
475 acpi_status status
= AE_OK
;
476 unsigned long flags
= 0;
478 ACPI_FLUSH_CPU_CACHE();
480 local_irq_save(flags
);
481 /* This shouldn't return. If it returns, we have a problem */
482 status
= acpi_enter_sleep_state(ACPI_STATE_S4
);
483 /* Reprogram control registers and execute _BFS */
484 acpi_leave_sleep_state_prep(ACPI_STATE_S4
);
485 local_irq_restore(flags
);
487 return ACPI_SUCCESS(status
) ? 0 : -EFAULT
;
490 static void acpi_hibernation_leave(void)
493 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
497 /* Reprogram control registers and execute _BFS */
498 acpi_leave_sleep_state_prep(ACPI_STATE_S4
);
499 /* Check the hardware signature */
500 if (facs
&& s4_hardware_signature
!= facs
->hardware_signature
) {
501 printk(KERN_EMERG
"ACPI: Hardware changed while hibernated, "
503 panic("ACPI S4 hardware signature mismatch");
505 /* Restore the NVS memory area */
506 suspend_nvs_restore();
507 /* Allow EC transactions to happen. */
508 acpi_ec_unblock_transactions_early();
511 static void acpi_pm_thaw(void)
513 acpi_ec_unblock_transactions();
514 acpi_enable_all_runtime_gpes();
517 static const struct platform_hibernation_ops acpi_hibernation_ops
= {
518 .begin
= acpi_hibernation_begin
,
520 .pre_snapshot
= acpi_pm_prepare
,
521 .finish
= acpi_pm_finish
,
522 .prepare
= acpi_pm_prepare
,
523 .enter
= acpi_hibernation_enter
,
524 .leave
= acpi_hibernation_leave
,
525 .pre_restore
= acpi_pm_freeze
,
526 .restore_cleanup
= acpi_pm_thaw
,
530 * acpi_hibernation_begin_old - Set the target system sleep state to
531 * ACPI_STATE_S4 and execute the _PTS control method. This
532 * function is used if the pre-ACPI 2.0 suspend ordering has been
535 static int acpi_hibernation_begin_old(void)
539 * The _TTS object should always be evaluated before the _PTS object.
540 * When the old_suspended_ordering is true, the _PTS object is
541 * evaluated in the acpi_sleep_prepare.
543 acpi_sleep_tts_switch(ACPI_STATE_S4
);
545 error
= acpi_sleep_prepare(ACPI_STATE_S4
);
549 error
= suspend_nvs_alloc();
551 acpi_target_sleep_state
= ACPI_STATE_S4
;
557 * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
560 static const struct platform_hibernation_ops acpi_hibernation_ops_old
= {
561 .begin
= acpi_hibernation_begin_old
,
563 .pre_snapshot
= acpi_pm_pre_suspend
,
564 .prepare
= acpi_pm_freeze
,
565 .finish
= acpi_pm_finish
,
566 .enter
= acpi_hibernation_enter
,
567 .leave
= acpi_hibernation_leave
,
568 .pre_restore
= acpi_pm_freeze
,
569 .restore_cleanup
= acpi_pm_thaw
,
570 .recover
= acpi_pm_finish
,
572 #endif /* CONFIG_HIBERNATION */
574 int acpi_suspend(u32 acpi_state
)
576 suspend_state_t states
[] = {
577 [1] = PM_SUSPEND_STANDBY
,
578 [3] = PM_SUSPEND_MEM
,
582 if (acpi_state
< 6 && states
[acpi_state
])
583 return pm_suspend(states
[acpi_state
]);
591 * acpi_pm_device_sleep_state - return preferred power state of ACPI device
592 * in the system sleep state given by %acpi_target_sleep_state
593 * @dev: device to examine; its driver model wakeup flags control
594 * whether it should be able to wake up the system
595 * @d_min_p: used to store the upper limit of allowed states range
596 * Return value: preferred power state of the device on success, -ENODEV on
597 * failure (ie. if there's no 'struct acpi_device' for @dev)
599 * Find the lowest power (highest number) ACPI device power state that
600 * device @dev can be in while the system is in the sleep state represented
601 * by %acpi_target_sleep_state. If @wake is nonzero, the device should be
602 * able to wake up the system from this sleep state. If @d_min_p is set,
603 * the highest power (lowest number) device power state of @dev allowed
604 * in this system sleep state is stored at the location pointed to by it.
606 * The caller must ensure that @dev is valid before using this function.
607 * The caller is also responsible for figuring out if the device is
608 * supposed to be able to wake up the system and passing this information
612 int acpi_pm_device_sleep_state(struct device
*dev
, int *d_min_p
)
614 acpi_handle handle
= DEVICE_ACPI_HANDLE(dev
);
615 struct acpi_device
*adev
;
616 char acpi_method
[] = "_SxD";
617 unsigned long long d_min
, d_max
;
619 if (!handle
|| ACPI_FAILURE(acpi_bus_get_device(handle
, &adev
))) {
620 printk(KERN_DEBUG
"ACPI handle has no context!\n");
624 acpi_method
[2] = '0' + acpi_target_sleep_state
;
626 * If the sleep state is S0, we will return D3, but if the device has
627 * _S0W, we will use the value from _S0W
629 d_min
= ACPI_STATE_D0
;
630 d_max
= ACPI_STATE_D3
;
633 * If present, _SxD methods return the minimum D-state (highest power
634 * state) we can use for the corresponding S-states. Otherwise, the
635 * minimum D-state is D0 (ACPI 3.x).
637 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
638 * provided -- that's our fault recovery, we ignore retval.
640 if (acpi_target_sleep_state
> ACPI_STATE_S0
)
641 acpi_evaluate_integer(handle
, acpi_method
, NULL
, &d_min
);
644 * If _PRW says we can wake up the system from the target sleep state,
645 * the D-state returned by _SxD is sufficient for that (we assume a
646 * wakeup-aware driver if wake is set). Still, if _SxW exists
647 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
648 * can wake the system. _S0W may be valid, too.
650 if (acpi_target_sleep_state
== ACPI_STATE_S0
||
651 (device_may_wakeup(dev
) &&
652 adev
->wakeup
.sleep_state
<= acpi_target_sleep_state
)) {
655 acpi_method
[3] = 'W';
656 status
= acpi_evaluate_integer(handle
, acpi_method
, NULL
,
658 if (ACPI_FAILURE(status
)) {
659 if (acpi_target_sleep_state
!= ACPI_STATE_S0
||
660 status
!= AE_NOT_FOUND
)
662 } else if (d_max
< d_min
) {
663 /* Warn the user of the broken DSDT */
664 printk(KERN_WARNING
"ACPI: Wrong value from %s\n",
675 #endif /* CONFIG_PM */
677 #ifdef CONFIG_PM_SLEEP
679 * acpi_pm_device_sleep_wake - enable or disable the system wake-up
680 * capability of given device
681 * @dev: device to handle
682 * @enable: 'true' - enable, 'false' - disable the wake-up capability
684 int acpi_pm_device_sleep_wake(struct device
*dev
, bool enable
)
687 struct acpi_device
*adev
;
690 if (!device_can_wakeup(dev
))
693 handle
= DEVICE_ACPI_HANDLE(dev
);
694 if (!handle
|| ACPI_FAILURE(acpi_bus_get_device(handle
, &adev
))) {
695 dev_dbg(dev
, "ACPI handle has no context in %s!\n", __func__
);
700 acpi_enable_wakeup_device_power(adev
, acpi_target_sleep_state
) :
701 acpi_disable_wakeup_device_power(adev
);
703 dev_info(dev
, "wake-up capability %s by ACPI\n",
704 enable
? "enabled" : "disabled");
708 #endif /* CONFIG_PM_SLEEP */
710 static void acpi_power_off_prepare(void)
712 /* Prepare to power off the system */
713 acpi_sleep_prepare(ACPI_STATE_S5
);
714 acpi_disable_all_gpes();
717 static void acpi_power_off(void)
719 /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
720 printk(KERN_DEBUG
"%s called\n", __func__
);
722 acpi_enter_sleep_state(ACPI_STATE_S5
);
726 * ACPI 2.0 created the optional _GTS and _BFS,
727 * but industry adoption has been neither rapid nor broad.
729 * Linux gets into trouble when it executes poorly validated
730 * paths through the BIOS, so disable _GTS and _BFS by default,
731 * but do speak up and offer the option to enable them.
733 static void __init
acpi_gts_bfs_check(void)
737 if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT
, METHOD_NAME__GTS
, &dummy
)))
739 printk(KERN_NOTICE PREFIX
"BIOS offers _GTS\n");
740 printk(KERN_NOTICE PREFIX
"If \"acpi.gts=1\" improves suspend, "
741 "please notify linux-acpi@vger.kernel.org\n");
743 if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT
, METHOD_NAME__BFS
, &dummy
)))
745 printk(KERN_NOTICE PREFIX
"BIOS offers _BFS\n");
746 printk(KERN_NOTICE PREFIX
"If \"acpi.bfs=1\" improves resume, "
747 "please notify linux-acpi@vger.kernel.org\n");
751 int __init
acpi_sleep_init(void)
755 #ifdef CONFIG_SUSPEND
758 dmi_check_system(acpisleep_dmi_table
);
764 sleep_states
[ACPI_STATE_S0
] = 1;
765 printk(KERN_INFO PREFIX
"(supports S0");
767 #ifdef CONFIG_SUSPEND
768 for (i
= ACPI_STATE_S1
; i
< ACPI_STATE_S4
; i
++) {
769 status
= acpi_get_sleep_type_data(i
, &type_a
, &type_b
);
770 if (ACPI_SUCCESS(status
)) {
776 suspend_set_ops(old_suspend_ordering
?
777 &acpi_suspend_ops_old
: &acpi_suspend_ops
);
780 #ifdef CONFIG_HIBERNATION
781 status
= acpi_get_sleep_type_data(ACPI_STATE_S4
, &type_a
, &type_b
);
782 if (ACPI_SUCCESS(status
)) {
783 hibernation_set_ops(old_suspend_ordering
?
784 &acpi_hibernation_ops_old
: &acpi_hibernation_ops
);
785 sleep_states
[ACPI_STATE_S4
] = 1;
788 acpi_get_table(ACPI_SIG_FACS
, 1,
789 (struct acpi_table_header
**)&facs
);
791 s4_hardware_signature
=
792 facs
->hardware_signature
;
796 status
= acpi_get_sleep_type_data(ACPI_STATE_S5
, &type_a
, &type_b
);
797 if (ACPI_SUCCESS(status
)) {
798 sleep_states
[ACPI_STATE_S5
] = 1;
800 pm_power_off_prepare
= acpi_power_off_prepare
;
801 pm_power_off
= acpi_power_off
;
805 * Register the tts_notifier to reboot notifier list so that the _TTS
806 * object can also be evaluated when the system enters S5.
808 register_reboot_notifier(&tts_notifier
);
809 acpi_gts_bfs_check();