xref: /openbmc/linux/drivers/acpi/x86/s2idle.c (revision ac3cb6de)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Architecture-specific ACPI-based support for suspend-to-idle.
4  *
5  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6  * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
7  * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
8  *
9  * On platforms supporting the Low Power S0 Idle interface there is an ACPI
10  * device object with the PNP0D80 compatible device ID (System Power Management
11  * Controller) and a specific _DSM method under it.  That method, if present,
12  * can be used to indicate to the platform that the OS is transitioning into a
13  * low-power state in which certain types of activity are not desirable or that
14  * it is leaving such a state, which allows the platform to adjust its operation
15  * mode accordingly.
16  */
17 
18 #include <linux/acpi.h>
19 #include <linux/device.h>
20 #include <linux/dmi.h>
21 #include <linux/suspend.h>
22 
23 #include "../sleep.h"
24 
25 #ifdef CONFIG_SUSPEND
26 
27 static bool sleep_no_lps0 __read_mostly;
28 module_param(sleep_no_lps0, bool, 0644);
29 MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");
30 
31 static const struct acpi_device_id lps0_device_ids[] = {
32 	{"PNP0D80", },
33 	{"", },
34 };
35 
36 /* Microsoft platform agnostic UUID */
37 #define ACPI_LPS0_DSM_UUID_MICROSOFT      "11e00d56-ce64-47ce-837b-1f898f9aa461"
38 
39 #define ACPI_LPS0_DSM_UUID	"c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
40 
41 #define ACPI_LPS0_GET_DEVICE_CONSTRAINTS	1
42 #define ACPI_LPS0_SCREEN_OFF	3
43 #define ACPI_LPS0_SCREEN_ON	4
44 #define ACPI_LPS0_ENTRY		5
45 #define ACPI_LPS0_EXIT		6
46 #define ACPI_LPS0_MS_ENTRY      7
47 #define ACPI_LPS0_MS_EXIT       8
48 
49 /* AMD */
50 #define ACPI_LPS0_DSM_UUID_AMD      "e3f32452-febc-43ce-9039-932122d37721"
51 #define ACPI_LPS0_ENTRY_AMD         2
52 #define ACPI_LPS0_EXIT_AMD          3
53 #define ACPI_LPS0_SCREEN_OFF_AMD    4
54 #define ACPI_LPS0_SCREEN_ON_AMD     5
55 
56 static acpi_handle lps0_device_handle;
57 static guid_t lps0_dsm_guid;
58 static int lps0_dsm_func_mask;
59 
60 static guid_t lps0_dsm_guid_microsoft;
61 static int lps0_dsm_func_mask_microsoft;
62 static int lps0_dsm_state;
63 
64 /* Device constraint entry structure */
65 struct lpi_device_info {
66 	char *name;
67 	int enabled;
68 	union acpi_object *package;
69 };
70 
71 /* Constraint package structure */
72 struct lpi_device_constraint {
73 	int uid;
74 	int min_dstate;
75 	int function_states;
76 };
77 
78 struct lpi_constraints {
79 	acpi_handle handle;
80 	int min_dstate;
81 };
82 
83 /* AMD Constraint package structure */
84 struct lpi_device_constraint_amd {
85 	char *name;
86 	int enabled;
87 	int function_states;
88 	int min_dstate;
89 };
90 
91 static LIST_HEAD(lps0_s2idle_devops_head);
92 
93 static struct lpi_constraints *lpi_constraints_table;
94 static int lpi_constraints_table_size;
95 static int rev_id;
96 
97 static void lpi_device_get_constraints_amd(void)
98 {
99 	union acpi_object *out_obj;
100 	int i, j, k;
101 
102 	out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
103 					  rev_id, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
104 					  NULL, ACPI_TYPE_PACKAGE);
105 
106 	acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
107 			  out_obj ? "successful" : "failed");
108 
109 	if (!out_obj)
110 		return;
111 
112 	for (i = 0; i < out_obj->package.count; i++) {
113 		union acpi_object *package = &out_obj->package.elements[i];
114 
115 		if (package->type == ACPI_TYPE_PACKAGE) {
116 			lpi_constraints_table = kcalloc(package->package.count,
117 							sizeof(*lpi_constraints_table),
118 							GFP_KERNEL);
119 
120 			if (!lpi_constraints_table)
121 				goto free_acpi_buffer;
122 
123 			acpi_handle_debug(lps0_device_handle,
124 					  "LPI: constraints list begin:\n");
125 
126 			for (j = 0; j < package->package.count; ++j) {
127 				union acpi_object *info_obj = &package->package.elements[j];
128 				struct lpi_device_constraint_amd dev_info = {};
129 				struct lpi_constraints *list;
130 				acpi_status status;
131 
132 				for (k = 0; k < info_obj->package.count; ++k) {
133 					union acpi_object *obj = &info_obj->package.elements[k];
134 
135 					list = &lpi_constraints_table[lpi_constraints_table_size];
136 					list->min_dstate = -1;
137 
138 					switch (k) {
139 					case 0:
140 						dev_info.enabled = obj->integer.value;
141 						break;
142 					case 1:
143 						dev_info.name = obj->string.pointer;
144 						break;
145 					case 2:
146 						dev_info.function_states = obj->integer.value;
147 						break;
148 					case 3:
149 						dev_info.min_dstate = obj->integer.value;
150 						break;
151 					}
152 
153 					if (!dev_info.enabled || !dev_info.name ||
154 					    !dev_info.min_dstate)
155 						continue;
156 
157 					status = acpi_get_handle(NULL, dev_info.name,
158 								 &list->handle);
159 					if (ACPI_FAILURE(status))
160 						continue;
161 
162 					acpi_handle_debug(lps0_device_handle,
163 							  "Name:%s\n", dev_info.name);
164 
165 					list->min_dstate = dev_info.min_dstate;
166 
167 					if (list->min_dstate < 0) {
168 						acpi_handle_debug(lps0_device_handle,
169 								  "Incomplete constraint defined\n");
170 						continue;
171 					}
172 				}
173 				lpi_constraints_table_size++;
174 			}
175 		}
176 	}
177 
178 	acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");
179 
180 free_acpi_buffer:
181 	ACPI_FREE(out_obj);
182 }
183 
184 static void lpi_device_get_constraints(void)
185 {
186 	union acpi_object *out_obj;
187 	int i;
188 
189 	out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
190 					  1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
191 					  NULL, ACPI_TYPE_PACKAGE);
192 
193 	acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
194 			  out_obj ? "successful" : "failed");
195 
196 	if (!out_obj)
197 		return;
198 
199 	lpi_constraints_table = kcalloc(out_obj->package.count,
200 					sizeof(*lpi_constraints_table),
201 					GFP_KERNEL);
202 	if (!lpi_constraints_table)
203 		goto free_acpi_buffer;
204 
205 	acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n");
206 
207 	for (i = 0; i < out_obj->package.count; i++) {
208 		struct lpi_constraints *constraint;
209 		acpi_status status;
210 		union acpi_object *package = &out_obj->package.elements[i];
211 		struct lpi_device_info info = { };
212 		int package_count = 0, j;
213 
214 		if (!package)
215 			continue;
216 
217 		for (j = 0; j < package->package.count; ++j) {
218 			union acpi_object *element =
219 					&(package->package.elements[j]);
220 
221 			switch (element->type) {
222 			case ACPI_TYPE_INTEGER:
223 				info.enabled = element->integer.value;
224 				break;
225 			case ACPI_TYPE_STRING:
226 				info.name = element->string.pointer;
227 				break;
228 			case ACPI_TYPE_PACKAGE:
229 				package_count = element->package.count;
230 				info.package = element->package.elements;
231 				break;
232 			}
233 		}
234 
235 		if (!info.enabled || !info.package || !info.name)
236 			continue;
237 
238 		constraint = &lpi_constraints_table[lpi_constraints_table_size];
239 
240 		status = acpi_get_handle(NULL, info.name, &constraint->handle);
241 		if (ACPI_FAILURE(status))
242 			continue;
243 
244 		acpi_handle_debug(lps0_device_handle,
245 				  "index:%d Name:%s\n", i, info.name);
246 
247 		constraint->min_dstate = -1;
248 
249 		for (j = 0; j < package_count; ++j) {
250 			union acpi_object *info_obj = &info.package[j];
251 			union acpi_object *cnstr_pkg;
252 			union acpi_object *obj;
253 			struct lpi_device_constraint dev_info;
254 
255 			switch (info_obj->type) {
256 			case ACPI_TYPE_INTEGER:
257 				/* version */
258 				break;
259 			case ACPI_TYPE_PACKAGE:
260 				if (info_obj->package.count < 2)
261 					break;
262 
263 				cnstr_pkg = info_obj->package.elements;
264 				obj = &cnstr_pkg[0];
265 				dev_info.uid = obj->integer.value;
266 				obj = &cnstr_pkg[1];
267 				dev_info.min_dstate = obj->integer.value;
268 
269 				acpi_handle_debug(lps0_device_handle,
270 					"uid:%d min_dstate:%s\n",
271 					dev_info.uid,
272 					acpi_power_state_string(dev_info.min_dstate));
273 
274 				constraint->min_dstate = dev_info.min_dstate;
275 				break;
276 			}
277 		}
278 
279 		if (constraint->min_dstate < 0) {
280 			acpi_handle_debug(lps0_device_handle,
281 					  "Incomplete constraint defined\n");
282 			continue;
283 		}
284 
285 		lpi_constraints_table_size++;
286 	}
287 
288 	acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");
289 
290 free_acpi_buffer:
291 	ACPI_FREE(out_obj);
292 }
293 
294 static void lpi_check_constraints(void)
295 {
296 	int i;
297 
298 	for (i = 0; i < lpi_constraints_table_size; ++i) {
299 		acpi_handle handle = lpi_constraints_table[i].handle;
300 		struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
301 
302 		if (!adev)
303 			continue;
304 
305 		acpi_handle_debug(handle,
306 			"LPI: required min power state:%s current power state:%s\n",
307 			acpi_power_state_string(lpi_constraints_table[i].min_dstate),
308 			acpi_power_state_string(adev->power.state));
309 
310 		if (!adev->flags.power_manageable) {
311 			acpi_handle_info(handle, "LPI: Device not power manageable\n");
312 			lpi_constraints_table[i].handle = NULL;
313 			continue;
314 		}
315 
316 		if (adev->power.state < lpi_constraints_table[i].min_dstate)
317 			acpi_handle_info(handle,
318 				"LPI: Constraint not met; min power state:%s current power state:%s\n",
319 				acpi_power_state_string(lpi_constraints_table[i].min_dstate),
320 				acpi_power_state_string(adev->power.state));
321 	}
322 }
323 
324 static bool acpi_s2idle_vendor_amd(void)
325 {
326 	return boot_cpu_data.x86_vendor == X86_VENDOR_AMD;
327 }
328 
329 static const char *acpi_sleep_dsm_state_to_str(unsigned int state)
330 {
331 	if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) {
332 		switch (state) {
333 		case ACPI_LPS0_SCREEN_OFF:
334 			return "screen off";
335 		case ACPI_LPS0_SCREEN_ON:
336 			return "screen on";
337 		case ACPI_LPS0_ENTRY:
338 			return "lps0 entry";
339 		case ACPI_LPS0_EXIT:
340 			return "lps0 exit";
341 		case ACPI_LPS0_MS_ENTRY:
342 			return "lps0 ms entry";
343 		case ACPI_LPS0_MS_EXIT:
344 			return "lps0 ms exit";
345 		}
346 	} else {
347 		switch (state) {
348 		case ACPI_LPS0_SCREEN_ON_AMD:
349 			return "screen on";
350 		case ACPI_LPS0_SCREEN_OFF_AMD:
351 			return "screen off";
352 		case ACPI_LPS0_ENTRY_AMD:
353 			return "lps0 entry";
354 		case ACPI_LPS0_EXIT_AMD:
355 			return "lps0 exit";
356 		}
357 	}
358 
359 	return "unknown";
360 }
361 
362 static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, guid_t dsm_guid)
363 {
364 	union acpi_object *out_obj;
365 
366 	if (!(func_mask & (1 << func)))
367 		return;
368 
369 	out_obj = acpi_evaluate_dsm(lps0_device_handle, &dsm_guid,
370 					rev_id, func, NULL);
371 	ACPI_FREE(out_obj);
372 
373 	lps0_dsm_state = func;
374 	if (pm_debug_messages_on) {
375 		acpi_handle_info(lps0_device_handle,
376 				"%s transitioned to state %s\n",
377 				 out_obj ? "Successfully" : "Failed to",
378 				 acpi_sleep_dsm_state_to_str(lps0_dsm_state));
379 	}
380 }
381 
382 
383 static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid)
384 {
385 	union acpi_object *obj;
386 	int ret = -EINVAL;
387 
388 	guid_parse(uuid, dsm_guid);
389 	obj = acpi_evaluate_dsm(handle, dsm_guid, rev, 0, NULL);
390 
391 	/* Check if the _DSM is present and as expected. */
392 	if (!obj || obj->type != ACPI_TYPE_BUFFER || obj->buffer.length == 0 ||
393 	    obj->buffer.length > sizeof(u32)) {
394 		acpi_handle_debug(handle,
395 				"_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev);
396 		goto out;
397 	}
398 
399 	ret = *(int *)obj->buffer.pointer;
400 	acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret);
401 
402 out:
403 	ACPI_FREE(obj);
404 	return ret;
405 }
406 
407 struct amd_lps0_hid_device_data {
408 	const bool check_off_by_one;
409 };
410 
411 static const struct amd_lps0_hid_device_data amd_picasso = {
412 	.check_off_by_one = true,
413 };
414 
415 static const struct amd_lps0_hid_device_data amd_cezanne = {
416 	.check_off_by_one = false,
417 };
418 
419 static const struct acpi_device_id amd_hid_ids[] = {
420 	{"AMD0004",	(kernel_ulong_t)&amd_picasso,	},
421 	{"AMD0005",	(kernel_ulong_t)&amd_picasso,	},
422 	{"AMDI0005",	(kernel_ulong_t)&amd_picasso,	},
423 	{"AMDI0006",	(kernel_ulong_t)&amd_cezanne,	},
424 	{}
425 };
426 
427 static int lps0_device_attach(struct acpi_device *adev,
428 			      const struct acpi_device_id *not_used)
429 {
430 	if (lps0_device_handle)
431 		return 0;
432 
433 	lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle,
434 						    ACPI_LPS0_DSM_UUID_MICROSOFT, 0,
435 						    &lps0_dsm_guid_microsoft);
436 	if (acpi_s2idle_vendor_amd()) {
437 		static const struct acpi_device_id *dev_id;
438 		const struct amd_lps0_hid_device_data *data;
439 
440 		for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++)
441 			if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL))
442 				break;
443 		if (dev_id->id[0])
444 			data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data;
445 		else
446 			data = &amd_cezanne;
447 		lps0_dsm_func_mask = validate_dsm(adev->handle,
448 					ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid);
449 		if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) {
450 			lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1;
451 			acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n",
452 					  ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask);
453 		} else if (lps0_dsm_func_mask_microsoft > 0 && rev_id) {
454 			lps0_dsm_func_mask_microsoft = -EINVAL;
455 			acpi_handle_debug(adev->handle, "_DSM Using AMD method\n");
456 		}
457 	} else {
458 		rev_id = 1;
459 		lps0_dsm_func_mask = validate_dsm(adev->handle,
460 					ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
461 		lps0_dsm_func_mask_microsoft = -EINVAL;
462 	}
463 
464 	if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
465 		return 0; //function evaluation failed
466 
467 	lps0_device_handle = adev->handle;
468 
469 	if (acpi_s2idle_vendor_amd())
470 		lpi_device_get_constraints_amd();
471 	else
472 		lpi_device_get_constraints();
473 
474 	/*
475 	 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in
476 	 * the FADT and the default suspend mode was not set from the command
477 	 * line.
478 	 */
479 	if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) &&
480 	    mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) {
481 		mem_sleep_current = PM_SUSPEND_TO_IDLE;
482 		pr_info("Low-power S0 idle used by default for system suspend\n");
483 	}
484 
485 	/*
486 	 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the
487 	 * EC GPE to be enabled while suspended for certain wakeup devices to
488 	 * work, so mark it as wakeup-capable.
489 	 */
490 	acpi_ec_mark_gpe_for_wake();
491 
492 	return 0;
493 }
494 
495 static struct acpi_scan_handler lps0_handler = {
496 	.ids = lps0_device_ids,
497 	.attach = lps0_device_attach,
498 };
499 
500 int acpi_s2idle_prepare_late(void)
501 {
502 	struct acpi_s2idle_dev_ops *handler;
503 
504 	if (!lps0_device_handle || sleep_no_lps0)
505 		return 0;
506 
507 	if (pm_debug_messages_on)
508 		lpi_check_constraints();
509 
510 	/* Screen off */
511 	if (lps0_dsm_func_mask > 0)
512 		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
513 					ACPI_LPS0_SCREEN_OFF_AMD :
514 					ACPI_LPS0_SCREEN_OFF,
515 					lps0_dsm_func_mask, lps0_dsm_guid);
516 
517 	if (lps0_dsm_func_mask_microsoft > 0)
518 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF,
519 				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
520 
521 	/* LPS0 entry */
522 	if (lps0_dsm_func_mask > 0)
523 		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
524 					ACPI_LPS0_ENTRY_AMD :
525 					ACPI_LPS0_ENTRY,
526 					lps0_dsm_func_mask, lps0_dsm_guid);
527 	if (lps0_dsm_func_mask_microsoft > 0) {
528 		/* modern standby entry */
529 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY,
530 				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
531 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY,
532 				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
533 	}
534 
535 	list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
536 		if (handler->prepare)
537 			handler->prepare();
538 	}
539 
540 	return 0;
541 }
542 
543 void acpi_s2idle_check(void)
544 {
545 	struct acpi_s2idle_dev_ops *handler;
546 
547 	if (!lps0_device_handle || sleep_no_lps0)
548 		return;
549 
550 	list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
551 		if (handler->check)
552 			handler->check();
553 	}
554 }
555 
556 void acpi_s2idle_restore_early(void)
557 {
558 	struct acpi_s2idle_dev_ops *handler;
559 
560 	if (!lps0_device_handle || sleep_no_lps0)
561 		return;
562 
563 	list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node)
564 		if (handler->restore)
565 			handler->restore();
566 
567 	/* LPS0 exit */
568 	if (lps0_dsm_func_mask > 0)
569 		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
570 					ACPI_LPS0_EXIT_AMD :
571 					ACPI_LPS0_EXIT,
572 					lps0_dsm_func_mask, lps0_dsm_guid);
573 	if (lps0_dsm_func_mask_microsoft > 0)
574 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT,
575 				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
576 
577 	/* Modern standby exit */
578 	if (lps0_dsm_func_mask_microsoft > 0)
579 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT,
580 				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
581 
582 	/* Screen on */
583 	if (lps0_dsm_func_mask_microsoft > 0)
584 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON,
585 				lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft);
586 	if (lps0_dsm_func_mask > 0)
587 		acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ?
588 					ACPI_LPS0_SCREEN_ON_AMD :
589 					ACPI_LPS0_SCREEN_ON,
590 					lps0_dsm_func_mask, lps0_dsm_guid);
591 }
592 
593 static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
594 	.begin = acpi_s2idle_begin,
595 	.prepare = acpi_s2idle_prepare,
596 	.prepare_late = acpi_s2idle_prepare_late,
597 	.check = acpi_s2idle_check,
598 	.wake = acpi_s2idle_wake,
599 	.restore_early = acpi_s2idle_restore_early,
600 	.restore = acpi_s2idle_restore,
601 	.end = acpi_s2idle_end,
602 };
603 
604 void __init acpi_s2idle_setup(void)
605 {
606 	acpi_scan_add_handler(&lps0_handler);
607 	s2idle_set_ops(&acpi_s2idle_ops_lps0);
608 }
609 
610 int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg)
611 {
612 	unsigned int sleep_flags;
613 
614 	if (!lps0_device_handle || sleep_no_lps0)
615 		return -ENODEV;
616 
617 	sleep_flags = lock_system_sleep();
618 	list_add(&arg->list_node, &lps0_s2idle_devops_head);
619 	unlock_system_sleep(sleep_flags);
620 
621 	return 0;
622 }
623 EXPORT_SYMBOL_GPL(acpi_register_lps0_dev);
624 
625 void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg)
626 {
627 	unsigned int sleep_flags;
628 
629 	if (!lps0_device_handle || sleep_no_lps0)
630 		return;
631 
632 	sleep_flags = lock_system_sleep();
633 	list_del(&arg->list_node);
634 	unlock_system_sleep(sleep_flags);
635 }
636 EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev);
637 
638 #endif /* CONFIG_SUSPEND */
639