xref: /openbmc/linux/drivers/acpi/acpica/hwsleep.c (revision b04b4f78)
1 
2 /******************************************************************************
3  *
4  * Name: hwsleep.c - ACPI Hardware Sleep/Wake Interface
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2008, Intel Corp.
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19  *    substantially similar to the "NO WARRANTY" disclaimer below
20  *    ("Disclaimer") and any redistribution must be conditioned upon
21  *    including a substantially similar Disclaimer requirement for further
22  *    binary redistribution.
23  * 3. Neither the names of the above-listed copyright holders nor the names
24  *    of any contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * Alternatively, this software may be distributed under the terms of the
28  * GNU General Public License ("GPL") version 2 as published by the Free
29  * Software Foundation.
30  *
31  * NO WARRANTY
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42  * POSSIBILITY OF SUCH DAMAGES.
43  */
44 
45 #include <acpi/acpi.h>
46 #include "accommon.h"
47 #include "actables.h"
48 
49 #define _COMPONENT          ACPI_HARDWARE
50 ACPI_MODULE_NAME("hwsleep")
51 
52 /*******************************************************************************
53  *
54  * FUNCTION:    acpi_set_firmware_waking_vector
55  *
56  * PARAMETERS:  physical_address    - 32-bit physical address of ACPI real mode
57  *                                    entry point.
58  *
59  * RETURN:      Status
60  *
61  * DESCRIPTION: Sets the 32-bit firmware_waking_vector field of the FACS
62  *
63  ******************************************************************************/
64 acpi_status
65 acpi_set_firmware_waking_vector(u32 physical_address)
66 {
67 	ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector);
68 
69 
70 	/*
71 	 * According to the ACPI specification 2.0c and later, the 64-bit
72 	 * waking vector should be cleared and the 32-bit waking vector should
73 	 * be used, unless we want the wake-up code to be called by the BIOS in
74 	 * Protected Mode.  Some systems (for example HP dv5-1004nr) are known
75 	 * to fail to resume if the 64-bit vector is used.
76 	 */
77 
78 	/* Set the 32-bit vector */
79 
80 	acpi_gbl_FACS->firmware_waking_vector = physical_address;
81 
82 	/* Clear the 64-bit vector if it exists */
83 
84 	if ((acpi_gbl_FACS->length > 32) && (acpi_gbl_FACS->version >= 1)) {
85 		acpi_gbl_FACS->xfirmware_waking_vector = 0;
86 	}
87 
88 	return_ACPI_STATUS(AE_OK);
89 }
90 
91 ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector)
92 
93 #if ACPI_MACHINE_WIDTH == 64
94 /*******************************************************************************
95  *
96  * FUNCTION:    acpi_set_firmware_waking_vector64
97  *
98  * PARAMETERS:  physical_address    - 64-bit physical address of ACPI protected
99  *                                    mode entry point.
100  *
101  * RETURN:      Status
102  *
103  * DESCRIPTION: Sets the 64-bit X_firmware_waking_vector field of the FACS, if
104  *              it exists in the table. This function is intended for use with
105  *              64-bit host operating systems.
106  *
107  ******************************************************************************/
108 acpi_status
109 acpi_set_firmware_waking_vector64(u64 physical_address)
110 {
111 	ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector64);
112 
113 
114 	/* Determine if the 64-bit vector actually exists */
115 
116 	if ((acpi_gbl_FACS->length <= 32) || (acpi_gbl_FACS->version < 1)) {
117 		return_ACPI_STATUS(AE_NOT_EXIST);
118 	}
119 
120 	/* Clear 32-bit vector, set the 64-bit X_ vector */
121 
122 	acpi_gbl_FACS->firmware_waking_vector = 0;
123 	acpi_gbl_FACS->xfirmware_waking_vector = physical_address;
124 
125 	return_ACPI_STATUS(AE_OK);
126 }
127 
128 ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector64)
129 #endif
130 
131 /*******************************************************************************
132  *
133  * FUNCTION:    acpi_enter_sleep_state_prep
134  *
135  * PARAMETERS:  sleep_state         - Which sleep state to enter
136  *
137  * RETURN:      Status
138  *
139  * DESCRIPTION: Prepare to enter a system sleep state (see ACPI 2.0 spec p 231)
140  *              This function must execute with interrupts enabled.
141  *              We break sleeping into 2 stages so that OSPM can handle
142  *              various OS-specific tasks between the two steps.
143  *
144  ******************************************************************************/
145 acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)
146 {
147 	acpi_status status;
148 	struct acpi_object_list arg_list;
149 	union acpi_object arg;
150 
151 	ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_prep);
152 
153 	/* _PSW methods could be run here to enable wake-on keyboard, LAN, etc. */
154 
155 	status = acpi_get_sleep_type_data(sleep_state,
156 					  &acpi_gbl_sleep_type_a,
157 					  &acpi_gbl_sleep_type_b);
158 	if (ACPI_FAILURE(status)) {
159 		return_ACPI_STATUS(status);
160 	}
161 
162 	/* Setup parameter object */
163 
164 	arg_list.count = 1;
165 	arg_list.pointer = &arg;
166 
167 	arg.type = ACPI_TYPE_INTEGER;
168 	arg.integer.value = sleep_state;
169 
170 	/* Run the _PTS method */
171 
172 	status = acpi_evaluate_object(NULL, METHOD_NAME__PTS, &arg_list, NULL);
173 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
174 		return_ACPI_STATUS(status);
175 	}
176 
177 	/* Setup the argument to _SST */
178 
179 	switch (sleep_state) {
180 	case ACPI_STATE_S0:
181 		arg.integer.value = ACPI_SST_WORKING;
182 		break;
183 
184 	case ACPI_STATE_S1:
185 	case ACPI_STATE_S2:
186 	case ACPI_STATE_S3:
187 		arg.integer.value = ACPI_SST_SLEEPING;
188 		break;
189 
190 	case ACPI_STATE_S4:
191 		arg.integer.value = ACPI_SST_SLEEP_CONTEXT;
192 		break;
193 
194 	default:
195 		arg.integer.value = ACPI_SST_INDICATOR_OFF;	/* Default is off */
196 		break;
197 	}
198 
199 	/*
200 	 * Set the system indicators to show the desired sleep state.
201 	 * _SST is an optional method (return no error if not found)
202 	 */
203 	status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
204 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
205 		ACPI_EXCEPTION((AE_INFO, status,
206 				"While executing method _SST"));
207 	}
208 
209 	return_ACPI_STATUS(AE_OK);
210 }
211 
212 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
213 
214 static unsigned int gts, bfs;
215 module_param(gts, uint, 0644);
216 module_param(bfs, uint, 0644);
217 MODULE_PARM_DESC(gts, "Enable evaluation of _GTS on suspend.");
218 MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);
219 
220 /*******************************************************************************
221  *
222  * FUNCTION:    acpi_enter_sleep_state
223  *
224  * PARAMETERS:  sleep_state         - Which sleep state to enter
225  *
226  * RETURN:      Status
227  *
228  * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
229  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
230  *
231  ******************************************************************************/
232 acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
233 {
234 	u32 pm1a_control;
235 	u32 pm1b_control;
236 	struct acpi_bit_register_info *sleep_type_reg_info;
237 	struct acpi_bit_register_info *sleep_enable_reg_info;
238 	u32 in_value;
239 	struct acpi_object_list arg_list;
240 	union acpi_object arg;
241 	acpi_status status;
242 
243 	ACPI_FUNCTION_TRACE(acpi_enter_sleep_state);
244 
245 	if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
246 	    (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
247 		ACPI_ERROR((AE_INFO, "Sleep values out of range: A=%X B=%X",
248 			    acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
249 		return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
250 	}
251 
252 	sleep_type_reg_info =
253 	    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
254 	sleep_enable_reg_info =
255 	    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
256 
257 	/* Clear wake status */
258 
259 	status =
260 	    acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, ACPI_CLEAR_STATUS);
261 	if (ACPI_FAILURE(status)) {
262 		return_ACPI_STATUS(status);
263 	}
264 
265 	/* Clear all fixed and general purpose status bits */
266 
267 	status = acpi_hw_clear_acpi_status();
268 	if (ACPI_FAILURE(status)) {
269 		return_ACPI_STATUS(status);
270 	}
271 
272 	/*
273 	 * 1) Disable/Clear all GPEs
274 	 * 2) Enable all wakeup GPEs
275 	 */
276 	status = acpi_hw_disable_all_gpes();
277 	if (ACPI_FAILURE(status)) {
278 		return_ACPI_STATUS(status);
279 	}
280 	acpi_gbl_system_awake_and_running = FALSE;
281 
282 	status = acpi_hw_enable_all_wakeup_gpes();
283 	if (ACPI_FAILURE(status)) {
284 		return_ACPI_STATUS(status);
285 	}
286 
287 	if (gts) {
288 		/* Execute the _GTS method */
289 
290 		arg_list.count = 1;
291 		arg_list.pointer = &arg;
292 		arg.type = ACPI_TYPE_INTEGER;
293 		arg.integer.value = sleep_state;
294 
295 		status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
296 		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
297 			return_ACPI_STATUS(status);
298 		}
299 	}
300 
301 	/* Get current value of PM1A control */
302 
303 	status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
304 				       &pm1a_control);
305 	if (ACPI_FAILURE(status)) {
306 		return_ACPI_STATUS(status);
307 	}
308 	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
309 			  "Entering sleep state [S%d]\n", sleep_state));
310 
311 	/* Clear the SLP_EN and SLP_TYP fields */
312 
313 	pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
314 			  sleep_enable_reg_info->access_bit_mask);
315 	pm1b_control = pm1a_control;
316 
317 	/* Insert the SLP_TYP bits */
318 
319 	pm1a_control |=
320 	    (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
321 	pm1b_control |=
322 	    (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
323 
324 	/*
325 	 * We split the writes of SLP_TYP and SLP_EN to workaround
326 	 * poorly implemented hardware.
327 	 */
328 
329 	/* Write #1: write the SLP_TYP data to the PM1 Control registers */
330 
331 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
332 	if (ACPI_FAILURE(status)) {
333 		return_ACPI_STATUS(status);
334 	}
335 
336 	/* Insert the sleep enable (SLP_EN) bit */
337 
338 	pm1a_control |= sleep_enable_reg_info->access_bit_mask;
339 	pm1b_control |= sleep_enable_reg_info->access_bit_mask;
340 
341 	/* Flush caches, as per ACPI specification */
342 
343 	ACPI_FLUSH_CPU_CACHE();
344 
345 	/* Write #2: Write both SLP_TYP + SLP_EN */
346 
347 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
348 	if (ACPI_FAILURE(status)) {
349 		return_ACPI_STATUS(status);
350 	}
351 
352 	if (sleep_state > ACPI_STATE_S3) {
353 		/*
354 		 * We wanted to sleep > S3, but it didn't happen (by virtue of the
355 		 * fact that we are still executing!)
356 		 *
357 		 * Wait ten seconds, then try again. This is to get S4/S5 to work on
358 		 * all machines.
359 		 *
360 		 * We wait so long to allow chipsets that poll this reg very slowly
361 		 * to still read the right value. Ideally, this block would go
362 		 * away entirely.
363 		 */
364 		acpi_os_stall(10000000);
365 
366 		status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
367 						sleep_enable_reg_info->
368 						access_bit_mask);
369 		if (ACPI_FAILURE(status)) {
370 			return_ACPI_STATUS(status);
371 		}
372 	}
373 
374 	/* Wait until we enter sleep state */
375 
376 	do {
377 		status = acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS,
378 						    &in_value);
379 		if (ACPI_FAILURE(status)) {
380 			return_ACPI_STATUS(status);
381 		}
382 
383 		/* Spin until we wake */
384 
385 	} while (!in_value);
386 
387 	return_ACPI_STATUS(AE_OK);
388 }
389 
390 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state)
391 
392 /*******************************************************************************
393  *
394  * FUNCTION:    acpi_enter_sleep_state_s4bios
395  *
396  * PARAMETERS:  None
397  *
398  * RETURN:      Status
399  *
400  * DESCRIPTION: Perform a S4 bios request.
401  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
402  *
403  ******************************************************************************/
404 acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void)
405 {
406 	u32 in_value;
407 	acpi_status status;
408 
409 	ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_s4bios);
410 
411 	/* Clear the wake status bit (PM1) */
412 
413 	status =
414 	    acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, ACPI_CLEAR_STATUS);
415 	if (ACPI_FAILURE(status)) {
416 		return_ACPI_STATUS(status);
417 	}
418 
419 	status = acpi_hw_clear_acpi_status();
420 	if (ACPI_FAILURE(status)) {
421 		return_ACPI_STATUS(status);
422 	}
423 
424 	/*
425 	 * 1) Disable/Clear all GPEs
426 	 * 2) Enable all wakeup GPEs
427 	 */
428 	status = acpi_hw_disable_all_gpes();
429 	if (ACPI_FAILURE(status)) {
430 		return_ACPI_STATUS(status);
431 	}
432 	acpi_gbl_system_awake_and_running = FALSE;
433 
434 	status = acpi_hw_enable_all_wakeup_gpes();
435 	if (ACPI_FAILURE(status)) {
436 		return_ACPI_STATUS(status);
437 	}
438 
439 	ACPI_FLUSH_CPU_CACHE();
440 
441 	status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
442 				    (u32) acpi_gbl_FADT.S4bios_request, 8);
443 
444 	do {
445 		acpi_os_stall(1000);
446 		status =
447 		    acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
448 		if (ACPI_FAILURE(status)) {
449 			return_ACPI_STATUS(status);
450 		}
451 	} while (!in_value);
452 
453 	return_ACPI_STATUS(AE_OK);
454 }
455 
456 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_s4bios)
457 
458 /*******************************************************************************
459  *
460  * FUNCTION:    acpi_leave_sleep_state_prep
461  *
462  * PARAMETERS:  sleep_state         - Which sleep state we are exiting
463  *
464  * RETURN:      Status
465  *
466  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
467  *              sleep.
468  *              Called with interrupts DISABLED.
469  *
470  ******************************************************************************/
471 acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
472 {
473 	struct acpi_object_list arg_list;
474 	union acpi_object arg;
475 	acpi_status status;
476 	struct acpi_bit_register_info *sleep_type_reg_info;
477 	struct acpi_bit_register_info *sleep_enable_reg_info;
478 	u32 pm1a_control;
479 	u32 pm1b_control;
480 
481 	ACPI_FUNCTION_TRACE(acpi_leave_sleep_state_prep);
482 
483 	/*
484 	 * Set SLP_TYPE and SLP_EN to state S0.
485 	 * This is unclear from the ACPI Spec, but it is required
486 	 * by some machines.
487 	 */
488 	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
489 					  &acpi_gbl_sleep_type_a,
490 					  &acpi_gbl_sleep_type_b);
491 	if (ACPI_SUCCESS(status)) {
492 		sleep_type_reg_info =
493 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
494 		sleep_enable_reg_info =
495 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
496 
497 		/* Get current value of PM1A control */
498 
499 		status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
500 					       &pm1a_control);
501 		if (ACPI_SUCCESS(status)) {
502 
503 			/* Clear the SLP_EN and SLP_TYP fields */
504 
505 			pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
506 					  sleep_enable_reg_info->
507 					  access_bit_mask);
508 			pm1b_control = pm1a_control;
509 
510 			/* Insert the SLP_TYP bits */
511 
512 			pm1a_control |= (acpi_gbl_sleep_type_a <<
513 					 sleep_type_reg_info->bit_position);
514 			pm1b_control |= (acpi_gbl_sleep_type_b <<
515 					 sleep_type_reg_info->bit_position);
516 
517 			/* Write the control registers and ignore any errors */
518 
519 			(void)acpi_hw_write_pm1_control(pm1a_control,
520 							pm1b_control);
521 		}
522 	}
523 
524 	if (bfs) {
525 		/* Execute the _BFS method */
526 
527 		arg_list.count = 1;
528 		arg_list.pointer = &arg;
529 		arg.type = ACPI_TYPE_INTEGER;
530 		arg.integer.value = sleep_state;
531 
532 		status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
533 		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
534 			ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
535 		}
536 	}
537 	return_ACPI_STATUS(status);
538 }
539 
540 /*******************************************************************************
541  *
542  * FUNCTION:    acpi_leave_sleep_state
543  *
544  * PARAMETERS:  sleep_state         - Which sleep state we just exited
545  *
546  * RETURN:      Status
547  *
548  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
549  *              Called with interrupts ENABLED.
550  *
551  ******************************************************************************/
552 acpi_status acpi_leave_sleep_state(u8 sleep_state)
553 {
554 	struct acpi_object_list arg_list;
555 	union acpi_object arg;
556 	acpi_status status;
557 
558 	ACPI_FUNCTION_TRACE(acpi_leave_sleep_state);
559 
560 	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
561 
562 	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
563 
564 	/* Setup parameter object */
565 
566 	arg_list.count = 1;
567 	arg_list.pointer = &arg;
568 	arg.type = ACPI_TYPE_INTEGER;
569 
570 	/* Ignore any errors from these methods */
571 
572 	arg.integer.value = ACPI_SST_WAKING;
573 	status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
574 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
575 		ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
576 	}
577 
578 	/*
579 	 * GPEs must be enabled before _WAK is called as GPEs
580 	 * might get fired there
581 	 *
582 	 * Restore the GPEs:
583 	 * 1) Disable/Clear all GPEs
584 	 * 2) Enable all runtime GPEs
585 	 */
586 	status = acpi_hw_disable_all_gpes();
587 	if (ACPI_FAILURE(status)) {
588 		return_ACPI_STATUS(status);
589 	}
590 	status = acpi_hw_enable_all_runtime_gpes();
591 	if (ACPI_FAILURE(status)) {
592 		return_ACPI_STATUS(status);
593 	}
594 
595 	arg.integer.value = sleep_state;
596 	status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
597 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
598 		ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
599 	}
600 	/* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
601 
602 	/*
603 	 * Some BIOSes assume that WAK_STS will be cleared on resume and use
604 	 * it to determine whether the system is rebooting or resuming. Clear
605 	 * it for compatibility.
606 	 */
607 	acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, 1);
608 
609 	acpi_gbl_system_awake_and_running = TRUE;
610 
611 	/* Enable power button */
612 
613 	(void)
614 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
615 			      [ACPI_EVENT_POWER_BUTTON].
616 			      enable_register_id, ACPI_ENABLE_EVENT);
617 
618 	(void)
619 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
620 			      [ACPI_EVENT_POWER_BUTTON].
621 			      status_register_id, ACPI_CLEAR_STATUS);
622 
623 	arg.integer.value = ACPI_SST_WORKING;
624 	status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
625 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
626 		ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
627 	}
628 
629 	return_ACPI_STATUS(status);
630 }
631 
632 ACPI_EXPORT_SYMBOL(acpi_leave_sleep_state)
633