summaryrefslogtreecommitdiff
path: root/drivers/acpi/x86/s2idle.c
blob: ce62e61a9605eb15dbfe711308b091733829843b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
// SPDX-License-Identifier: GPL-2.0
/*
 * Architecture-specific ACPI-based support for suspend-to-idle.
 *
 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
 * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
 *
 * On platforms supporting the Low Power S0 Idle interface there is an ACPI
 * device object with the PNP0D80 compatible device ID (System Power Management
 * Controller) and a specific _DSM method under it.  That method, if present,
 * can be used to indicate to the platform that the OS is transitioning into a
 * low-power state in which certain types of activity are not desirable or that
 * it is leaving such a state, which allows the platform to adjust its operation
 * mode accordingly.
 */

#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/dmi.h>
#include <linux/suspend.h>

#include "../sleep.h"

#ifdef CONFIG_SUSPEND

static bool sleep_no_lps0 __read_mostly;
module_param(sleep_no_lps0, bool, 0644);
MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");

static const struct acpi_device_id lps0_device_ids[] = {
	{"PNP0D80", },
	{"", },
};

/* Microsoft platform agnostic UUID */
#define ACPI_LPS0_DSM_UUID_MICROSOFT      "11e00d56-ce64-47ce-837b-1f898f9aa461"

#define ACPI_LPS0_DSM_UUID	"c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"

#define ACPI_LPS0_GET_DEVICE_CONSTRAINTS	1
#define ACPI_LPS0_SCREEN_OFF	3
#define ACPI_LPS0_SCREEN_ON	4
#define ACPI_LPS0_ENTRY		5
#define ACPI_LPS0_EXIT		6
#define ACPI_LPS0_MS_ENTRY      7
#define ACPI_LPS0_MS_EXIT       8

/* AMD */
#define ACPI_LPS0_DSM_UUID_AMD      "e3f32452-febc-43ce-9039-932122d37721"
#define ACPI_LPS0_ENTRY_AMD         2
#define ACPI_LPS0_EXIT_AMD          3
#define ACPI_LPS0_SCREEN_OFF_AMD    4
#define ACPI_LPS0_SCREEN_ON_AMD     5

static acpi_handle lps0_device_handle;
static guid_t lps0_dsm_guid;
static int lps0_dsm_func_mask;

static guid_t lps0_dsm_guid_microsoft;
static int lps0_dsm_func_mask_microsoft;
static int lps0_dsm_state;

/* Device constraint entry structure */
struct lpi_device_info {
	char *name;
	int enabled;
	union acpi_object *package;
};

/* Constraint package structure */
struct lpi_device_constraint {
	int uid;
	int min_dstate;
	int function_states;
};

struct lpi_constraints {
	acpi_handle handle;
	int min_dstate;
};

/* AMD Constraint package structure */
struct lpi_device_constraint_amd {
	char *name;
	int enabled;
	int function_states;
	int min_dstate;
};

static LIST_HEAD(lps0_s2idle_devops_head);

static struct lpi_constraints *lpi_constraints_table;
static int lpi_constraints_table_size;
static int rev_id;

static void lpi_device_get_constraints_amd(void)
{
	union acpi_object *out_obj;
	int i, j, k;

	out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
					  rev_id, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
					  NULL, ACPI_TYPE_PACKAGE);

	acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
			  out_obj ? "successful" : "failed");

	if (!out_obj)
		return;

	for (i = 0; i < out_obj->package.count; i++) {
		union acpi_object *package = &out_obj->package.elements[i];

		if (package->type == ACPI_TYPE_PACKAGE) {
			lpi_constraints_table = kcalloc(package->package.count,
							sizeof(*lpi_constraints_table),
							GFP_KERNEL);

			if (!lpi_constraints_table)
				goto free_acpi_buffer;

			acpi_handle_debug(lps0_device_handle,
					  "LPI: constraints list begin:\n");

			for (j = 0; j < package->package.count; ++j) {
				union acpi_object *info_obj = &package->package.elements[j];
				struct lpi_device_constraint_amd dev_info = {};
				struct lpi_constraints *list;
				acpi_status status;

				for (k = 0; k < info_obj->package.count; ++k) {
					union acpi_object *obj = &info_obj->package.elements[k];

					list = &lpi_constraints_table[lpi_constraints_table_size];
					list->min_dstate = -1;

					switch (k) {
					case 0:
						dev_info.enabled = obj->integer.value;
						break;
					case 1:
						dev_info.name = obj->string.pointer;
						break;
					case 2:
						dev_info.function_states = obj->integer.value;
						break;
					case 3:
						dev_info.min_dstate = obj->integer.value;
						break;
					}

					if (!dev_info.enabled || !dev_info.name ||
					    !dev_info.min_dstate)
						continue;

					status = acpi_get_handle(NULL, dev_info.name,
								 &list->handle);
					if (ACPI_FAILURE(status))
						continue;

					acpi_handle_debug(lps0_device_handle,
							  "Name:%s\n", dev_info.name);

					list->min_dstate = dev_info.min_dstate;

					if (list->min_dstate < 0) {
						acpi_handle_debug(lps0_device_handle,
								  "Incomplete constraint defined\n");
						continue;
					}
				}
				lpi_constraints_table_size++;
			}
		}
	}

	acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");

free_acpi_buffer:
	ACPI_FREE(out_obj);
}

static void lpi_device_get_constraints(void)
{
	union acpi_object *out_obj;
	int i;

	out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
					  1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
					  NULL, ACPI_TYPE_PACKAGE);

	acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
			  out_obj ? "successful" : "failed");

	if (!out_obj)
		return;

	lpi_constraints_table = kcalloc(out_obj->package.count,
					sizeof(*lpi_constraints_table),
					GFP_KERNEL);
	if (!lpi_constraints_table)
		goto free_acpi_buffer;

	acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n");

	for (i = 0; i < out_obj->package.count; i++) {
		struct lpi_constraints *constraint;
		acpi_status status;
		union acpi_object *package = &out_obj->package.elements[i];
		struct lpi_device_info info = { };
		int package_count = 0, j;

		if (!package)
			continue;

		for (j = 0; j < package->package.count; ++j) {
			union acpi_object *element =
					&(package->package.elements[j]);

			switch (element->type) {
			case ACPI_TYPE_INTEGER:
				info.enabled = element->integer.value;
				break;
			case ACPI_TYPE_STRING:
				info.name = element->string.pointer;
				break;
			case ACPI_TYPE_PACKAGE:
				package_count = element->package.count;
				info.package = element->package.elements;
				break;
			}
		}

		if (!info.enabled || !info.package || !info.name)
			continue;

		constraint = &lpi_constraints_table[lpi_constraints_table_size];

		status = acpi_get_handle(NULL, info.name, &constraint->handle);
		if (ACPI_FAILURE(status))
			continue;

		acpi_handle_debug(lps0_device_handle,
				  "index:%d Name:%s\n", i, info.name);

		constraint->min_dstate = -1;

		for (j = 0; j < package_count; ++j) {
			union acpi_object *info_obj = &info.package[j];
			union acpi_object *cnstr_pkg;
			union acpi_object *obj;
			struct lpi_device_constraint dev_info;

			switch (info_obj->type) {
			case ACPI_TYPE_INTEGER:
				/* version */
				break;
			case ACPI_TYPE_PACKAGE:
				if (info_obj->package.count < 2)
					break;

				cnstr_pkg = info_obj->package.elements;
				obj = &cnstr_pkg[0];
				dev_info.uid = obj->integer.value;
				obj = &cnstr_pkg[1];
				dev_info.min_dstate = obj->integer.value;

				acpi_handle_debug(lps0_device_handle,
					"uid:%d min_dstate:%s\n",
					dev_info.uid,
					acpi_power_state_string(dev_info.min_dstate));

				constraint->min_dstate = dev_info.min_dstate;
				break;
			}
		}

		if (constraint->min_dstate < 0) {
			acpi_handle_debug(lps0_device_handle,
					  "Incomplete constraint defined\n");
			continue;
		}

		lpi_constraints_table_size++;
	}

	acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");

free_acpi_buffer:
	ACPI_FREE(out_obj);
}

static void lpi_check_constraints(void)
{
	int i;

	for (i = 0; i < lpi_constraints_table_size; ++i) {
		acpi_handle handle = lpi_constraints_table[i].handle;
		struct acpi_device *adev = acpi_fetch_acpi_dev(handle);

		if (!adev)
			continue;

		acpi_handle_debug(handle,
			"LPI: required min power state:%s current power state:%s\n",
			acpi_power_state_string(lpi_constraints_table[i].min_dstate),
			acpi_power_state_string(adev->power.state));

		if (!adev->flags.power_manageable) {
			acpi_handle_info(handle, "LPI: Device not power manageable\n");
			lpi_constraints_table[i].handle = NULL;
			continue;
		}

		if (adev->power.state < lpi_constraints_table[i].min_dstate)
			acpi_handle_info(handle,
				"LPI: Constraint not met; min power state:%s current power state:%s\n",
				acpi_power_state_string(lpi_constraints_table[i].min_dstate),
				acpi_power_state_string(adev->power.state));
	}
}

static bool acpi_s2idle_vendor_amd(void)
{
	return boot_cpu_data.x86_vendor == X86_VENDOR_AMD;
}

static const char *acpi_sleep_dsm_state_to_str(unsigned int state)
{
	if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) {
		switch (state) {
		case ACPI_LPS0_SCREEN_OFF:
			return "screen off";
		case ACPI_LPS0_SCREEN_ON:
			return "screen on";
		case ACPI_LPS0_ENTRY:
			return "lps0 entry";
		case ACPI_LPS0_EXIT:
			return "lps0 exit";
		case ACPI_LPS0_MS_ENTRY:
			return "lps0 ms entry";
		case ACPI_LPS0_MS_EXIT:
			return "lps0 ms exit";
		}
	} else {
		switch (state) {
		case ACPI_LPS0_SCREEN_ON_AMD:
			return "screen on";
		case ACPI_LPS0_SCREEN_OFF_AMD:
			return "screen off";
		case ACPI_LPS0_ENTRY_AMD:
			return "lps0 entry";
		case ACPI_LPS0_EXIT_AMD:
			return "lps0 exit";
		}
	}

	return "unknown";
}

static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, guid_t dsm_guid)
{
	union acpi_object *out_obj;

	if (!(func_mask & (1 << func)))
		return;

	out_obj = acpi_evaluate_dsm(lps0_device_handle, &dsm_guid,
					rev_id, func, NULL);
	ACPI_FREE(out_obj);

	lps0_dsm_state = func;
	if (pm_debug_messages_on) {
		acpi_handle_info(lps0_device_handle,
				"%s transitioned to state %s\n",
				 out_obj ? "Successfully" : "Failed to",
				 acpi_sleep_dsm_state_to_str(lps0_dsm_state));
	}
}


static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid)
{
	union acpi_object *obj;
	int ret = -EINVAL;

	guid_parse(uuid, dsm_guid);
	obj = acpi_evaluate_dsm(handle, dsm_guid, rev, 0, NULL);

	/* Check if the _DSM is present and as expected. */
	if (!obj || obj->type != ACPI_TYPE_BUFFER || obj->buffer.length == 0 ||
	    obj->buffer.length > sizeof(u32)) {
		acpi_handle_debug(handle,
				"_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev);
		goto out;
	}

	ret = *(int *)obj->buffer.pointer;
	acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret);

out:
	ACPI_FREE(obj);
	return ret;
}

struct amd_lps0_hid_device_data {
	const bool check_off_by_one;
};

static const struct amd_lps0_hid_device_data amd_picasso = {
	.check_off_by_one = true,
};

static const struct amd_lps0_hid_device_data amd_cezanne = {
	.check_off_by_one = false,
};

static const struct acpi_device_id amd_hid_ids[] = {
	{"AMD0004",	(kernel_ulong_t)&amd_picasso,	},
	{"AMD0005",	(kernel_ulong_t)&amd_picasso,	},
	{"AMDI0005",	(kernel_ulong_t)&amd_picasso,	},
	{"AMDI0006",	(kernel_ulong_t)&amd_cezanne,	},
	{}
};

static int lps0_device_attach(struct acpi_device *adev,
			      const struct acpi_device_id *not_used)
{
	if (lps0_device_handle)
		return 0;

	lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle,
						    ACPI_LPS0_DSM_UUID_MICROSOFT, 0,
						    &lps0_dsm_guid_microsoft);
	if (acpi_s2idle_vendor_amd()) {
		static const struct acpi_device_id *dev_id;
		const struct amd_lps0_hid_device_data *data;

		for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++)
			if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL))
				break;
		if (dev_id->id[0])
			data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data;
		else
			data = &amd_cezanne;
		lps0_dsm_func_mask = validate_dsm(adev->handle,
					ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid);
		if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) {
			lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1;
			acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n",
					  ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask);
		} else if (lps0_dsm_func_mask_microsoft > 0 && rev_id) {
			lps0_dsm_func_mask_microsoft = -EINVAL;
			acpi_handle_debug(adev->handle, "_DSM Using AMD method\n");
		}
	} else {
		rev_id = 1;
		lps0_dsm_func_mask = validate_dsm(adev->handle,
					ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
		lps0_dsm_func_mask_microsoft = -EINVAL;
	}

	if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
		return 0; //function evaluation failed

	lps0_device_handle = adev->handle;

	if (acpi_s2idle_vendor_amd())
		lpi_device_get_constraints_amd();
	else
		lpi_device_get_constraints();

	/*
	 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in
	 * the FADT and the default suspend mode was not set from the command
	 * line.
	 */
	if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) &&
	    mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) {
		mem_sleep_current = PM_SUSPEND_TO_IDLE;
		pr_info("Low-power S0 idle used by default for system suspend\n");
	}

	/*
	 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the
	 * EC GPE to be enabled while suspended for certain wakeup devices to
	 * work, so mark it as wakeup-capable.
	 */
	acpi_ec_mark_gpe_for_wake();

	return 0;
}

static struct acpi_scan_handler lps0_handler = {
	.ids = lps0_device_ids,
	.attach = lps0_device_attach,
};

int acpi_s2idle_prepare_late(void)
{
	struct acpi_s2idle_dev_ops *handler;

	if (!lps0_device_handle || sleep_no_lps0)
		return 0;

	if (pm_debug_messages_on)
		lpi_check_constraints();

	/* Screen off */
	if (lps0_dsm_func_mask > 0)
		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
					ACPI_LPS0_SCREEN_OFF_AMD :
					ACPI_LPS0_SCREEN_OFF,
					lps0_dsm_func_mask, lps0_dsm_guid);

	if (lps0_dsm_func_mask_microsoft > 0)
		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF,
				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);

	/* LPS0 entry */
	if (lps0_dsm_func_mask > 0)
		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
					ACPI_LPS0_ENTRY_AMD :
					ACPI_LPS0_ENTRY,
					lps0_dsm_func_mask, lps0_dsm_guid);
	if (lps0_dsm_func_mask_microsoft > 0) {
		/* modern standby entry */
		acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
		acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
	}

	list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
		if (handler->prepare)
			handler->prepare();
	}

	return 0;
}

void acpi_s2idle_check(void)
{
	struct acpi_s2idle_dev_ops *handler;

	if (!lps0_device_handle || sleep_no_lps0)
		return;

	list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
		if (handler->check)
			handler->check();
	}
}

void acpi_s2idle_restore_early(void)
{
	struct acpi_s2idle_dev_ops *handler;

	if (!lps0_device_handle || sleep_no_lps0)
		return;

	list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
		if (handler->restore)
			handler->restore();

	/* LPS0 exit */
	if (lps0_dsm_func_mask > 0)
		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
					ACPI_LPS0_EXIT_AMD :
					ACPI_LPS0_EXIT,
					lps0_dsm_func_mask, lps0_dsm_guid);
	if (lps0_dsm_func_mask_microsoft > 0)
		acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);

	/* Modern standby exit */
	if (lps0_dsm_func_mask_microsoft > 0)
		acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);

	/* Screen on */
	if (lps0_dsm_func_mask_microsoft > 0)
		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON,
				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
	if (lps0_dsm_func_mask > 0)
		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
					ACPI_LPS0_SCREEN_ON_AMD :
					ACPI_LPS0_SCREEN_ON,
					lps0_dsm_func_mask, lps0_dsm_guid);
}

static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
	.begin = acpi_s2idle_begin,
	.prepare = acpi_s2idle_prepare,
	.prepare_late = acpi_s2idle_prepare_late,
	.check = acpi_s2idle_check,
	.wake = acpi_s2idle_wake,
	.restore_early = acpi_s2idle_restore_early,
	.restore = acpi_s2idle_restore,
	.end = acpi_s2idle_end,
};

void __init acpi_s2idle_setup(void)
{
	acpi_scan_add_handler(&lps0_handler);
	s2idle_set_ops(&acpi_s2idle_ops_lps0);
}

int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
{
	unsigned int sleep_flags;

	if (!lps0_device_handle || sleep_no_lps0)
		return -ENODEV;

	sleep_flags = lock_system_sleep();
	list_add(&arg->list_node, &lps0_s2idle_devops_head);
	unlock_system_sleep(sleep_flags);

	return 0;
}
EXPORT_SYMBOL_GPL(acpi_register_lps0_dev);

void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg)
{
	unsigned int sleep_flags;

	if (!lps0_device_handle || sleep_no_lps0)
		return;

	sleep_flags = lock_system_sleep();
	list_del(&arg->list_node);
	unlock_system_sleep(sleep_flags);
}
EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev);

#endif /* CONFIG_SUSPEND */