Showing error 1242

User: Jiri Slaby
Error type: Leaving function in locked state
Error type description: Some lock is not unlocked on all paths of a function, so it is leaked
File location: drivers/acpi/sleep/main.c
Line in file: 635
Project: Linux Kernel
Project version: 2.6.28
Tools: Stanse (1.2)
Entered: 2012-05-21 20:30:05 UTC


Source:

  1/*
  2 * sleep.c - ACPI sleep support.
  3 *
  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
  8 *
  9 * This file is released under the GPLv2.
 10 *
 11 */
 12
 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
 20#include <asm/io.h>
 21
 22#include <acpi/acpi_bus.h>
 23#include <acpi/acpi_drivers.h>
 24#include "sleep.h"
 25
 26u8 sleep_states[ACPI_S_STATE_COUNT];
 27
 28static void acpi_sleep_tts_switch(u32 acpi_state)
 29{
 30        union acpi_object in_arg = { ACPI_TYPE_INTEGER };
 31        struct acpi_object_list arg_list = { 1, &in_arg };
 32        acpi_status status = AE_OK;
 33
 34        in_arg.integer.value = acpi_state;
 35        status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
 36        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 37                /*
 38                 * OS can't evaluate the _TTS object correctly. Some warning
 39                 * message will be printed. But it won't break anything.
 40                 */
 41                printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
 42        }
 43}
 44
 45static int tts_notify_reboot(struct notifier_block *this,
 46                        unsigned long code, void *x)
 47{
 48        acpi_sleep_tts_switch(ACPI_STATE_S5);
 49        return NOTIFY_DONE;
 50}
 51
 52static struct notifier_block tts_notifier = {
 53        .notifier_call        = tts_notify_reboot,
 54        .next                = NULL,
 55        .priority        = 0,
 56};
 57
 58static int acpi_sleep_prepare(u32 acpi_state)
 59{
 60#ifdef CONFIG_ACPI_SLEEP
 61        /* do we have a wakeup address for S2 and S3? */
 62        if (acpi_state == ACPI_STATE_S3) {
 63                if (!acpi_wakeup_address) {
 64                        return -EFAULT;
 65                }
 66                acpi_set_firmware_waking_vector(
 67                                (acpi_physical_address)acpi_wakeup_address);
 68
 69        }
 70        ACPI_FLUSH_CPU_CACHE();
 71        acpi_enable_wakeup_device_prep(acpi_state);
 72#endif
 73        printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
 74                acpi_state);
 75        acpi_enter_sleep_state_prep(acpi_state);
 76        return 0;
 77}
 78
 79#ifdef CONFIG_ACPI_SLEEP
 80static u32 acpi_target_sleep_state = ACPI_STATE_S0;
 81/*
 82 * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
 83 * user to request that behavior by using the 'acpi_old_suspend_ordering'
 84 * kernel command line option that causes the following variable to be set.
 85 */
 86static bool old_suspend_ordering;
 87
 88void __init acpi_old_suspend_ordering(void)
 89{
 90        old_suspend_ordering = true;
 91}
 92
 93/*
 94 * According to the ACPI specification the BIOS should make sure that ACPI is
 95 * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
 96 * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
 97 * on such systems during resume.  Unfortunately that doesn't help in
 98 * particularly pathological cases in which SCI_EN has to be set directly on
 99 * resume, although the specification states very clearly that this flag is
100 * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
101 * cases.
102 */
103static bool set_sci_en_on_resume;
104
105/**
106 *        acpi_pm_disable_gpes - Disable the GPEs.
107 */
108static int acpi_pm_disable_gpes(void)
109{
110        acpi_hw_disable_all_gpes();
111        return 0;
112}
113
114/**
115 *        __acpi_pm_prepare - Prepare the platform to enter the target state.
116 *
117 *        If necessary, set the firmware waking vector and do arch-specific
118 *        nastiness to get the wakeup code to the waking vector.
119 */
120static int __acpi_pm_prepare(void)
121{
122        int error = acpi_sleep_prepare(acpi_target_sleep_state);
123
124        if (error)
125                acpi_target_sleep_state = ACPI_STATE_S0;
126        return error;
127}
128
129/**
130 *        acpi_pm_prepare - Prepare the platform to enter the target sleep
131 *                state and disable the GPEs.
132 */
133static int acpi_pm_prepare(void)
134{
135        int error = __acpi_pm_prepare();
136
137        if (!error)
138                acpi_hw_disable_all_gpes();
139        return error;
140}
141
142/**
143 *        acpi_pm_finish - Instruct the platform to leave a sleep state.
144 *
145 *        This is called after we wake back up (or if entering the sleep state
146 *        failed).
147 */
148static void acpi_pm_finish(void)
149{
150        u32 acpi_state = acpi_target_sleep_state;
151
152        if (acpi_state == ACPI_STATE_S0)
153                return;
154
155        printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
156                acpi_state);
157        acpi_disable_wakeup_device(acpi_state);
158        acpi_leave_sleep_state(acpi_state);
159
160        /* reset firmware waking vector */
161        acpi_set_firmware_waking_vector((acpi_physical_address) 0);
162
163        acpi_target_sleep_state = ACPI_STATE_S0;
164}
165
166/**
167 *        acpi_pm_end - Finish up suspend sequence.
168 */
169static void acpi_pm_end(void)
170{
171        /*
172         * This is necessary in case acpi_pm_finish() is not called during a
173         * failing transition to a sleep state.
174         */
175        acpi_target_sleep_state = ACPI_STATE_S0;
176        acpi_sleep_tts_switch(acpi_target_sleep_state);
177}
178#else /* !CONFIG_ACPI_SLEEP */
179#define acpi_target_sleep_state        ACPI_STATE_S0
180#endif /* CONFIG_ACPI_SLEEP */
181
182#ifdef CONFIG_SUSPEND
183extern void do_suspend_lowlevel(void);
184
185static u32 acpi_suspend_states[] = {
186        [PM_SUSPEND_ON] = ACPI_STATE_S0,
187        [PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
188        [PM_SUSPEND_MEM] = ACPI_STATE_S3,
189        [PM_SUSPEND_MAX] = ACPI_STATE_S5
190};
191
192/**
193 *        acpi_suspend_begin - Set the target system sleep state to the state
194 *                associated with given @pm_state, if supported.
195 */
196static int acpi_suspend_begin(suspend_state_t pm_state)
197{
198        u32 acpi_state = acpi_suspend_states[pm_state];
199        int error = 0;
200
201        if (sleep_states[acpi_state]) {
202                acpi_target_sleep_state = acpi_state;
203                acpi_sleep_tts_switch(acpi_target_sleep_state);
204        } else {
205                printk(KERN_ERR "ACPI does not support this state: %d\n",
206                        pm_state);
207                error = -ENOSYS;
208        }
209        return error;
210}
211
212/**
213 *        acpi_suspend_enter - Actually enter a sleep state.
214 *        @pm_state: ignored
215 *
216 *        Flush caches and go to sleep. For STR we have to call arch-specific
217 *        assembly, which in turn call acpi_enter_sleep_state().
218 *        It's unfortunate, but it works. Please fix if you're feeling frisky.
219 */
220static int acpi_suspend_enter(suspend_state_t pm_state)
221{
222        acpi_status status = AE_OK;
223        unsigned long flags = 0;
224        u32 acpi_state = acpi_target_sleep_state;
225
226        ACPI_FLUSH_CPU_CACHE();
227
228        /* Do arch specific saving of state. */
229        if (acpi_state == ACPI_STATE_S3) {
230                int error = acpi_save_state_mem();
231
232                if (error)
233                        return error;
234        }
235
236        local_irq_save(flags);
237        acpi_enable_wakeup_device(acpi_state);
238        switch (acpi_state) {
239        case ACPI_STATE_S1:
240                barrier();
241                status = acpi_enter_sleep_state(acpi_state);
242                break;
243
244        case ACPI_STATE_S3:
245                do_suspend_lowlevel();
246                break;
247        }
248
249        /* If ACPI is not enabled by the BIOS, we need to enable it here. */
250        if (set_sci_en_on_resume)
251                acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
252        else
253                acpi_enable();
254
255        /* Reprogram control registers and execute _BFS */
256        acpi_leave_sleep_state_prep(acpi_state);
257
258        /* ACPI 3.0 specs (P62) says that it's the responsibility
259         * of the OSPM to clear the status bit [ implying that the
260         * POWER_BUTTON event should not reach userspace ]
261         */
262        if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
263                acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
264
265        /*
266         * Disable and clear GPE status before interrupt is enabled. Some GPEs
267         * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
268         * acpi_leave_sleep_state will reenable specific GPEs later
269         */
270        acpi_hw_disable_all_gpes();
271
272        local_irq_restore(flags);
273        printk(KERN_DEBUG "Back to C!\n");
274
275        /* restore processor state */
276        if (acpi_state == ACPI_STATE_S3)
277                acpi_restore_state_mem();
278
279        return ACPI_SUCCESS(status) ? 0 : -EFAULT;
280}
281
282static int acpi_suspend_state_valid(suspend_state_t pm_state)
283{
284        u32 acpi_state;
285
286        switch (pm_state) {
287        case PM_SUSPEND_ON:
288        case PM_SUSPEND_STANDBY:
289        case PM_SUSPEND_MEM:
290                acpi_state = acpi_suspend_states[pm_state];
291
292                return sleep_states[acpi_state];
293        default:
294                return 0;
295        }
296}
297
298static struct platform_suspend_ops acpi_suspend_ops = {
299        .valid = acpi_suspend_state_valid,
300        .begin = acpi_suspend_begin,
301        .prepare = acpi_pm_prepare,
302        .enter = acpi_suspend_enter,
303        .finish = acpi_pm_finish,
304        .end = acpi_pm_end,
305};
306
307/**
308 *        acpi_suspend_begin_old - Set the target system sleep state to the
309 *                state associated with given @pm_state, if supported, and
310 *                execute the _PTS control method.  This function is used if the
311 *                pre-ACPI 2.0 suspend ordering has been requested.
312 */
313static int acpi_suspend_begin_old(suspend_state_t pm_state)
314{
315        int error = acpi_suspend_begin(pm_state);
316
317        if (!error)
318                error = __acpi_pm_prepare();
319        return error;
320}
321
322/*
323 * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
324 * been requested.
325 */
326static struct platform_suspend_ops acpi_suspend_ops_old = {
327        .valid = acpi_suspend_state_valid,
328        .begin = acpi_suspend_begin_old,
329        .prepare = acpi_pm_disable_gpes,
330        .enter = acpi_suspend_enter,
331        .finish = acpi_pm_finish,
332        .end = acpi_pm_end,
333        .recover = acpi_pm_finish,
334};
335
336static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
337{
338        old_suspend_ordering = true;
339        return 0;
340}
341
342static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
343{
344        set_sci_en_on_resume = true;
345        return 0;
346}
347
348static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
349        {
350        .callback = init_old_suspend_ordering,
351        .ident = "Abit KN9 (nForce4 variant)",
352        .matches = {
353                DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
354                DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
355                },
356        },
357        {
358        .callback = init_old_suspend_ordering,
359        .ident = "HP xw4600 Workstation",
360        .matches = {
361                DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
362                DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
363                },
364        },
365        {
366        .callback = init_set_sci_en_on_resume,
367        .ident = "Apple MacBook 1,1",
368        .matches = {
369                DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
370                DMI_MATCH(DMI_PRODUCT_NAME, "MacBook1,1"),
371                },
372        },
373        {
374        .callback = init_set_sci_en_on_resume,
375        .ident = "Apple MacMini 1,1",
376        .matches = {
377                DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
378                DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
379                },
380        },
381        {},
382};
383#endif /* CONFIG_SUSPEND */
384
385#ifdef CONFIG_HIBERNATION
386static unsigned long s4_hardware_signature;
387static struct acpi_table_facs *facs;
388static bool nosigcheck;
389
390void __init acpi_no_s4_hw_signature(void)
391{
392        nosigcheck = true;
393}
394
395static int acpi_hibernation_begin(void)
396{
397        acpi_target_sleep_state = ACPI_STATE_S4;
398        acpi_sleep_tts_switch(acpi_target_sleep_state);
399        return 0;
400}
401
402static int acpi_hibernation_enter(void)
403{
404        acpi_status status = AE_OK;
405        unsigned long flags = 0;
406
407        ACPI_FLUSH_CPU_CACHE();
408
409        local_irq_save(flags);
410        acpi_enable_wakeup_device(ACPI_STATE_S4);
411        /* This shouldn't return.  If it returns, we have a problem */
412        status = acpi_enter_sleep_state(ACPI_STATE_S4);
413        /* Reprogram control registers and execute _BFS */
414        acpi_leave_sleep_state_prep(ACPI_STATE_S4);
415        local_irq_restore(flags);
416
417        return ACPI_SUCCESS(status) ? 0 : -EFAULT;
418}
419
420static void acpi_hibernation_leave(void)
421{
422        /*
423         * If ACPI is not enabled by the BIOS and the boot kernel, we need to
424         * enable it here.
425         */
426        acpi_enable();
427        /* Reprogram control registers and execute _BFS */
428        acpi_leave_sleep_state_prep(ACPI_STATE_S4);
429        /* Check the hardware signature */
430        if (facs && s4_hardware_signature != facs->hardware_signature) {
431                printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
432                        "cannot resume!\n");
433                panic("ACPI S4 hardware signature mismatch");
434        }
435}
436
437static void acpi_pm_enable_gpes(void)
438{
439        acpi_hw_enable_all_runtime_gpes();
440}
441
442static struct platform_hibernation_ops acpi_hibernation_ops = {
443        .begin = acpi_hibernation_begin,
444        .end = acpi_pm_end,
445        .pre_snapshot = acpi_pm_prepare,
446        .finish = acpi_pm_finish,
447        .prepare = acpi_pm_prepare,
448        .enter = acpi_hibernation_enter,
449        .leave = acpi_hibernation_leave,
450        .pre_restore = acpi_pm_disable_gpes,
451        .restore_cleanup = acpi_pm_enable_gpes,
452};
453
454/**
455 *        acpi_hibernation_begin_old - Set the target system sleep state to
456 *                ACPI_STATE_S4 and execute the _PTS control method.  This
457 *                function is used if the pre-ACPI 2.0 suspend ordering has been
458 *                requested.
459 */
460static int acpi_hibernation_begin_old(void)
461{
462        int error;
463        /*
464         * The _TTS object should always be evaluated before the _PTS object.
465         * When the old_suspended_ordering is true, the _PTS object is
466         * evaluated in the acpi_sleep_prepare.
467         */
468        acpi_sleep_tts_switch(ACPI_STATE_S4);
469
470        error = acpi_sleep_prepare(ACPI_STATE_S4);
471
472        if (!error)
473                acpi_target_sleep_state = ACPI_STATE_S4;
474        return error;
475}
476
477/*
478 * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
479 * been requested.
480 */
481static struct platform_hibernation_ops acpi_hibernation_ops_old = {
482        .begin = acpi_hibernation_begin_old,
483        .end = acpi_pm_end,
484        .pre_snapshot = acpi_pm_disable_gpes,
485        .finish = acpi_pm_finish,
486        .prepare = acpi_pm_disable_gpes,
487        .enter = acpi_hibernation_enter,
488        .leave = acpi_hibernation_leave,
489        .pre_restore = acpi_pm_disable_gpes,
490        .restore_cleanup = acpi_pm_enable_gpes,
491        .recover = acpi_pm_finish,
492};
493#endif /* CONFIG_HIBERNATION */
494
495int acpi_suspend(u32 acpi_state)
496{
497        suspend_state_t states[] = {
498                [1] = PM_SUSPEND_STANDBY,
499                [3] = PM_SUSPEND_MEM,
500                [5] = PM_SUSPEND_MAX
501        };
502
503        if (acpi_state < 6 && states[acpi_state])
504                return pm_suspend(states[acpi_state]);
505        if (acpi_state == 4)
506                return hibernate();
507        return -EINVAL;
508}
509
510#ifdef CONFIG_PM_SLEEP
511/**
512 *        acpi_pm_device_sleep_state - return preferred power state of ACPI device
513 *                in the system sleep state given by %acpi_target_sleep_state
514 *        @dev: device to examine; its driver model wakeup flags control
515 *                whether it should be able to wake up the system
516 *        @d_min_p: used to store the upper limit of allowed states range
517 *        Return value: preferred power state of the device on success, -ENODEV on
518 *                failure (ie. if there's no 'struct acpi_device' for @dev)
519 *
520 *        Find the lowest power (highest number) ACPI device power state that
521 *        device @dev can be in while the system is in the sleep state represented
522 *        by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
523 *        able to wake up the system from this sleep state.  If @d_min_p is set,
524 *        the highest power (lowest number) device power state of @dev allowed
525 *        in this system sleep state is stored at the location pointed to by it.
526 *
527 *        The caller must ensure that @dev is valid before using this function.
528 *        The caller is also responsible for figuring out if the device is
529 *        supposed to be able to wake up the system and passing this information
530 *        via @wake.
531 */
532
533int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
534{
535        acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
536        struct acpi_device *adev;
537        char acpi_method[] = "_SxD";
538        unsigned long long d_min, d_max;
539
540        if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
541                printk(KERN_DEBUG "ACPI handle has no context!\n");
542                return -ENODEV;
543        }
544
545        acpi_method[2] = '0' + acpi_target_sleep_state;
546        /*
547         * If the sleep state is S0, we will return D3, but if the device has
548         * _S0W, we will use the value from _S0W
549         */
550        d_min = ACPI_STATE_D0;
551        d_max = ACPI_STATE_D3;
552
553        /*
554         * If present, _SxD methods return the minimum D-state (highest power
555         * state) we can use for the corresponding S-states.  Otherwise, the
556         * minimum D-state is D0 (ACPI 3.x).
557         *
558         * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
559         * provided -- that's our fault recovery, we ignore retval.
560         */
561        if (acpi_target_sleep_state > ACPI_STATE_S0)
562                acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
563
564        /*
565         * If _PRW says we can wake up the system from the target sleep state,
566         * the D-state returned by _SxD is sufficient for that (we assume a
567         * wakeup-aware driver if wake is set).  Still, if _SxW exists
568         * (ACPI 3.x), it should return the maximum (lowest power) D-state that
569         * can wake the system.  _S0W may be valid, too.
570         */
571        if (acpi_target_sleep_state == ACPI_STATE_S0 ||
572            (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
573             adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
574                acpi_status status;
575
576                acpi_method[3] = 'W';
577                status = acpi_evaluate_integer(handle, acpi_method, NULL,
578                                                &d_max);
579                if (ACPI_FAILURE(status)) {
580                        d_max = d_min;
581                } else if (d_max < d_min) {
582                        /* Warn the user of the broken DSDT */
583                        printk(KERN_WARNING "ACPI: Wrong value from %s\n",
584                                acpi_method);
585                        /* Sanitize it */
586                        d_min = d_max;
587                }
588        }
589
590        if (d_min_p)
591                *d_min_p = d_min;
592        return d_max;
593}
594
595/**
596 *        acpi_pm_device_sleep_wake - enable or disable the system wake-up
597 *                                  capability of given device
598 *        @dev: device to handle
599 *        @enable: 'true' - enable, 'false' - disable the wake-up capability
600 */
601int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
602{
603        acpi_handle handle;
604        struct acpi_device *adev;
605
606        if (!device_may_wakeup(dev))
607                return -EINVAL;
608
609        handle = DEVICE_ACPI_HANDLE(dev);
610        if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
611                printk(KERN_DEBUG "ACPI handle has no context!\n");
612                return -ENODEV;
613        }
614
615        return enable ?
616                acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
617                acpi_disable_wakeup_device_power(adev);
618}
619#endif
620
621static void acpi_power_off_prepare(void)
622{
623        /* Prepare to power off the system */
624        acpi_sleep_prepare(ACPI_STATE_S5);
625        acpi_hw_disable_all_gpes();
626}
627
628static void acpi_power_off(void)
629{
630        /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
631        printk("%s called\n", __func__);
632        local_irq_disable();
633        acpi_enable_wakeup_device(ACPI_STATE_S5);
634        acpi_enter_sleep_state(ACPI_STATE_S5);
635}
636
637int __init acpi_sleep_init(void)
638{
639        acpi_status status;
640        u8 type_a, type_b;
641#ifdef CONFIG_SUSPEND
642        int i = 0;
643
644        dmi_check_system(acpisleep_dmi_table);
645#endif
646
647        if (acpi_disabled)
648                return 0;
649
650        sleep_states[ACPI_STATE_S0] = 1;
651        printk(KERN_INFO PREFIX "(supports S0");
652
653#ifdef CONFIG_SUSPEND
654        for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
655                status = acpi_get_sleep_type_data(i, &type_a, &type_b);
656                if (ACPI_SUCCESS(status)) {
657                        sleep_states[i] = 1;
658                        printk(" S%d", i);
659                }
660        }
661
662        suspend_set_ops(old_suspend_ordering ?
663                &acpi_suspend_ops_old : &acpi_suspend_ops);
664#endif
665
666#ifdef CONFIG_HIBERNATION
667        status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
668        if (ACPI_SUCCESS(status)) {
669                hibernation_set_ops(old_suspend_ordering ?
670                        &acpi_hibernation_ops_old : &acpi_hibernation_ops);
671                sleep_states[ACPI_STATE_S4] = 1;
672                printk(" S4");
673                if (!nosigcheck) {
674                        acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
675                                (struct acpi_table_header **)&facs);
676                        if (facs)
677                                s4_hardware_signature =
678                                        facs->hardware_signature;
679                }
680        }
681#endif
682        status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
683        if (ACPI_SUCCESS(status)) {
684                sleep_states[ACPI_STATE_S5] = 1;
685                printk(" S5");
686                pm_power_off_prepare = acpi_power_off_prepare;
687                pm_power_off = acpi_power_off;
688        }
689        printk(")\n");
690        /*
691         * Register the tts_notifier to reboot notifier list so that the _TTS
692         * object can also be evaluated when the system enters S5.
693         */
694        register_reboot_notifier(&tts_notifier);
695        return 0;
696}