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 27static bool sleep_no_lps0 __read_mostly; 28module_param(sleep_no_lps0, bool, 0644); 29MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface"); 30 31static 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 56static acpi_handle lps0_device_handle; 57static guid_t lps0_dsm_guid; 58static int lps0_dsm_func_mask; 59 60static guid_t lps0_dsm_guid_microsoft; 61static int lps0_dsm_func_mask_microsoft; 62static int lps0_dsm_state; 63 64/* Device constraint entry structure */ 65struct lpi_device_info { 66 char *name; 67 int enabled; 68 union acpi_object *package; 69}; 70 71/* Constraint package structure */ 72struct lpi_device_constraint { 73 int uid; 74 int min_dstate; 75 int function_states; 76}; 77 78struct lpi_constraints { 79 acpi_handle handle; 80 int min_dstate; 81}; 82 83/* AMD Constraint package structure */ 84struct lpi_device_constraint_amd { 85 char *name; 86 int enabled; 87 int function_states; 88 int min_dstate; 89}; 90 91static LIST_HEAD(lps0_s2idle_devops_head); 92 93static struct lpi_constraints *lpi_constraints_table; 94static int lpi_constraints_table_size; 95static int rev_id; 96 97#define for_each_lpi_constraint(entry) \ 98 for (int i = 0; \ 99 entry = &lpi_constraints_table[i], i < lpi_constraints_table_size; \ 100 i++) 101 102static void lpi_device_get_constraints_amd(void) 103{ 104 union acpi_object *out_obj; 105 int i, j, k; 106 107 out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid, 108 rev_id, ACPI_LPS0_GET_DEVICE_CONSTRAINTS, 109 NULL, ACPI_TYPE_PACKAGE); 110 111 acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n", 112 out_obj ? "successful" : "failed"); 113 114 if (!out_obj) 115 return; 116 117 for (i = 0; i < out_obj->package.count; i++) { 118 union acpi_object *package = &out_obj->package.elements[i]; 119 120 if (package->type == ACPI_TYPE_PACKAGE) { 121 if (lpi_constraints_table) { 122 acpi_handle_err(lps0_device_handle, 123 "Duplicate constraints list\n"); 124 goto free_acpi_buffer; 125 } 126 127 lpi_constraints_table = kcalloc(package->package.count, 128 sizeof(*lpi_constraints_table), 129 GFP_KERNEL); 130 131 if (!lpi_constraints_table) 132 goto free_acpi_buffer; 133 134 acpi_handle_debug(lps0_device_handle, 135 "LPI: constraints list begin:\n"); 136 137 for (j = 0; j < package->package.count; j++) { 138 union acpi_object *info_obj = &package->package.elements[j]; 139 struct lpi_device_constraint_amd dev_info = {}; 140 struct lpi_constraints *list; 141 acpi_status status; 142 143 list = &lpi_constraints_table[lpi_constraints_table_size]; 144 145 for (k = 0; k < info_obj->package.count; k++) { 146 union acpi_object *obj = &info_obj->package.elements[k]; 147 148 switch (k) { 149 case 0: 150 dev_info.enabled = obj->integer.value; 151 break; 152 case 1: 153 dev_info.name = obj->string.pointer; 154 break; 155 case 2: 156 dev_info.function_states = obj->integer.value; 157 break; 158 case 3: 159 dev_info.min_dstate = obj->integer.value; 160 break; 161 } 162 } 163 164 acpi_handle_debug(lps0_device_handle, 165 "Name:%s, Enabled: %d, States: %d, MinDstate: %d\n", 166 dev_info.name, 167 dev_info.enabled, 168 dev_info.function_states, 169 dev_info.min_dstate); 170 171 if (!dev_info.enabled || !dev_info.name || 172 !dev_info.min_dstate) 173 continue; 174 175 status = acpi_get_handle(NULL, dev_info.name, &list->handle); 176 if (ACPI_FAILURE(status)) 177 continue; 178 179 list->min_dstate = dev_info.min_dstate; 180 181 lpi_constraints_table_size++; 182 } 183 } 184 } 185 186 acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n"); 187 188free_acpi_buffer: 189 ACPI_FREE(out_obj); 190} 191 192static void lpi_device_get_constraints(void) 193{ 194 union acpi_object *out_obj; 195 int i; 196 197 out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid, 198 1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS, 199 NULL, ACPI_TYPE_PACKAGE); 200 201 acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n", 202 out_obj ? "successful" : "failed"); 203 204 if (!out_obj) 205 return; 206 207 lpi_constraints_table = kcalloc(out_obj->package.count, 208 sizeof(*lpi_constraints_table), 209 GFP_KERNEL); 210 if (!lpi_constraints_table) 211 goto free_acpi_buffer; 212 213 acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n"); 214 215 for (i = 0; i < out_obj->package.count; i++) { 216 struct lpi_constraints *constraint; 217 acpi_status status; 218 union acpi_object *package = &out_obj->package.elements[i]; 219 struct lpi_device_info info = { }; 220 int package_count = 0, j; 221 222 if (!package) 223 continue; 224 225 for (j = 0; j < package->package.count; j++) { 226 union acpi_object *element = 227 &(package->package.elements[j]); 228 229 switch (element->type) { 230 case ACPI_TYPE_INTEGER: 231 info.enabled = element->integer.value; 232 break; 233 case ACPI_TYPE_STRING: 234 info.name = element->string.pointer; 235 break; 236 case ACPI_TYPE_PACKAGE: 237 package_count = element->package.count; 238 info.package = element->package.elements; 239 break; 240 } 241 } 242 243 if (!info.enabled || !info.package || !info.name) 244 continue; 245 246 constraint = &lpi_constraints_table[lpi_constraints_table_size]; 247 248 status = acpi_get_handle(NULL, info.name, &constraint->handle); 249 if (ACPI_FAILURE(status)) 250 continue; 251 252 acpi_handle_debug(lps0_device_handle, 253 "index:%d Name:%s\n", i, info.name); 254 255 constraint->min_dstate = -1; 256 257 for (j = 0; j < package_count; j++) { 258 union acpi_object *info_obj = &info.package[j]; 259 union acpi_object *cnstr_pkg; 260 union acpi_object *obj; 261 struct lpi_device_constraint dev_info; 262 263 switch (info_obj->type) { 264 case ACPI_TYPE_INTEGER: 265 /* version */ 266 break; 267 case ACPI_TYPE_PACKAGE: 268 if (info_obj->package.count < 2) 269 break; 270 271 cnstr_pkg = info_obj->package.elements; 272 obj = &cnstr_pkg[0]; 273 dev_info.uid = obj->integer.value; 274 obj = &cnstr_pkg[1]; 275 dev_info.min_dstate = obj->integer.value; 276 277 acpi_handle_debug(lps0_device_handle, 278 "uid:%d min_dstate:%s\n", 279 dev_info.uid, 280 acpi_power_state_string(dev_info.min_dstate)); 281 282 constraint->min_dstate = dev_info.min_dstate; 283 break; 284 } 285 } 286 287 if (constraint->min_dstate < 0) { 288 acpi_handle_debug(lps0_device_handle, 289 "Incomplete constraint defined\n"); 290 continue; 291 } 292 293 lpi_constraints_table_size++; 294 } 295 296 acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n"); 297 298free_acpi_buffer: 299 ACPI_FREE(out_obj); 300} 301 302/** 303 * acpi_get_lps0_constraint - Get the LPS0 constraint for a device. 304 * @adev: Device to get the constraint for. 305 * 306 * The LPS0 constraint is the shallowest (minimum) power state in which the 307 * device can be so as to allow the platform as a whole to achieve additional 308 * energy conservation by utilizing a system-wide low-power state. 309 * 310 * Returns: 311 * - ACPI power state value of the constraint for @adev on success. 312 * - Otherwise, ACPI_STATE_UNKNOWN. 313 */ 314int acpi_get_lps0_constraint(struct acpi_device *adev) 315{ 316 struct lpi_constraints *entry; 317 318 for_each_lpi_constraint(entry) { 319 if (adev->handle == entry->handle) 320 return entry->min_dstate; 321 } 322 323 return ACPI_STATE_UNKNOWN; 324} 325 326static void lpi_check_constraints(void) 327{ 328 struct lpi_constraints *entry; 329 330 for_each_lpi_constraint(entry) { 331 struct acpi_device *adev = acpi_fetch_acpi_dev(entry->handle); 332 333 if (!adev) 334 continue; 335 336 acpi_handle_debug(entry->handle, 337 "LPI: required min power state:%s current power state:%s\n", 338 acpi_power_state_string(entry->min_dstate), 339 acpi_power_state_string(adev->power.state)); 340 341 if (!adev->flags.power_manageable) { 342 acpi_handle_info(entry->handle, "LPI: Device not power manageable\n"); 343 entry->handle = NULL; 344 continue; 345 } 346 347 if (adev->power.state < entry->min_dstate) 348 acpi_handle_info(entry->handle, 349 "LPI: Constraint not met; min power state:%s current power state:%s\n", 350 acpi_power_state_string(entry->min_dstate), 351 acpi_power_state_string(adev->power.state)); 352 } 353} 354 355static bool acpi_s2idle_vendor_amd(void) 356{ 357 return boot_cpu_data.x86_vendor == X86_VENDOR_AMD; 358} 359 360static const char *acpi_sleep_dsm_state_to_str(unsigned int state) 361{ 362 if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) { 363 switch (state) { 364 case ACPI_LPS0_SCREEN_OFF: 365 return "screen off"; 366 case ACPI_LPS0_SCREEN_ON: 367 return "screen on"; 368 case ACPI_LPS0_ENTRY: 369 return "lps0 entry"; 370 case ACPI_LPS0_EXIT: 371 return "lps0 exit"; 372 case ACPI_LPS0_MS_ENTRY: 373 return "lps0 ms entry"; 374 case ACPI_LPS0_MS_EXIT: 375 return "lps0 ms exit"; 376 } 377 } else { 378 switch (state) { 379 case ACPI_LPS0_SCREEN_ON_AMD: 380 return "screen on"; 381 case ACPI_LPS0_SCREEN_OFF_AMD: 382 return "screen off"; 383 case ACPI_LPS0_ENTRY_AMD: 384 return "lps0 entry"; 385 case ACPI_LPS0_EXIT_AMD: 386 return "lps0 exit"; 387 } 388 } 389 390 return "unknown"; 391} 392 393static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, guid_t dsm_guid) 394{ 395 union acpi_object *out_obj; 396 397 if (!(func_mask & (1 << func))) 398 return; 399 400 out_obj = acpi_evaluate_dsm(lps0_device_handle, &dsm_guid, 401 rev_id, func, NULL); 402 ACPI_FREE(out_obj); 403 404 lps0_dsm_state = func; 405 if (pm_debug_messages_on) { 406 acpi_handle_info(lps0_device_handle, 407 "%s transitioned to state %s\n", 408 out_obj ? "Successfully" : "Failed to", 409 acpi_sleep_dsm_state_to_str(lps0_dsm_state)); 410 } 411} 412 413 414static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid) 415{ 416 union acpi_object *obj; 417 int ret = -EINVAL; 418 419 guid_parse(uuid, dsm_guid); 420 421 /* Check if the _DSM is present and as expected. */ 422 obj = acpi_evaluate_dsm_typed(handle, dsm_guid, rev, 0, NULL, ACPI_TYPE_BUFFER); 423 if (!obj || obj->buffer.length == 0 || obj->buffer.length > sizeof(u32)) { 424 acpi_handle_debug(handle, 425 "_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev); 426 goto out; 427 } 428 429 ret = *(int *)obj->buffer.pointer; 430 acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret); 431 432out: 433 ACPI_FREE(obj); 434 return ret; 435} 436 437struct amd_lps0_hid_device_data { 438 const bool check_off_by_one; 439}; 440 441static const struct amd_lps0_hid_device_data amd_picasso = { 442 .check_off_by_one = true, 443}; 444 445static const struct amd_lps0_hid_device_data amd_cezanne = { 446 .check_off_by_one = false, 447}; 448 449static const struct acpi_device_id amd_hid_ids[] = { 450 {"AMD0004", (kernel_ulong_t)&amd_picasso, }, 451 {"AMD0005", (kernel_ulong_t)&amd_picasso, }, 452 {"AMDI0005", (kernel_ulong_t)&amd_picasso, }, 453 {"AMDI0006", (kernel_ulong_t)&amd_cezanne, }, 454 {} 455}; 456 457static int lps0_device_attach(struct acpi_device *adev, 458 const struct acpi_device_id *not_used) 459{ 460 if (lps0_device_handle) 461 return 0; 462 463 lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle, 464 ACPI_LPS0_DSM_UUID_MICROSOFT, 0, 465 &lps0_dsm_guid_microsoft); 466 if (acpi_s2idle_vendor_amd()) { 467 static const struct acpi_device_id *dev_id; 468 const struct amd_lps0_hid_device_data *data; 469 470 for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++) 471 if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL)) 472 break; 473 if (dev_id->id[0]) 474 data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data; 475 else 476 data = &amd_cezanne; 477 lps0_dsm_func_mask = validate_dsm(adev->handle, 478 ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid); 479 if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) { 480 lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1; 481 acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n", 482 ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask); 483 } else if (lps0_dsm_func_mask_microsoft > 0 && rev_id) { 484 lps0_dsm_func_mask_microsoft = -EINVAL; 485 acpi_handle_debug(adev->handle, "_DSM Using AMD method\n"); 486 } 487 } else { 488 rev_id = 1; 489 lps0_dsm_func_mask = validate_dsm(adev->handle, 490 ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid); 491 if (lps0_dsm_func_mask > 0 && lps0_dsm_func_mask_microsoft > 0) { 492 unsigned int func_mask; 493 494 /* 495 * Log a message if the _DSM function sets for two 496 * different UUIDs overlap. 497 */ 498 func_mask = lps0_dsm_func_mask & lps0_dsm_func_mask_microsoft; 499 if (func_mask) 500 acpi_handle_info(adev->handle, 501 "Duplicate LPS0 _DSM functions (mask: 0x%x)\n", 502 func_mask); 503 } 504 } 505 506 if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0) 507 return 0; //function evaluation failed 508 509 lps0_device_handle = adev->handle; 510 511 if (acpi_s2idle_vendor_amd()) 512 lpi_device_get_constraints_amd(); 513 else 514 lpi_device_get_constraints(); 515 516 /* 517 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in 518 * the FADT and the default suspend mode was not set from the command 519 * line. 520 */ 521 if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) && 522 mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) { 523 mem_sleep_current = PM_SUSPEND_TO_IDLE; 524 pr_info("Low-power S0 idle used by default for system suspend\n"); 525 } 526 527 /* 528 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the 529 * EC GPE to be enabled while suspended for certain wakeup devices to 530 * work, so mark it as wakeup-capable. 531 */ 532 acpi_ec_mark_gpe_for_wake(); 533 534 return 0; 535} 536 537static struct acpi_scan_handler lps0_handler = { 538 .ids = lps0_device_ids, 539 .attach = lps0_device_attach, 540}; 541 542int acpi_s2idle_prepare_late(void) 543{ 544 struct acpi_s2idle_dev_ops *handler; 545 546 if (!lps0_device_handle || sleep_no_lps0) 547 return 0; 548 549 if (pm_debug_messages_on) 550 lpi_check_constraints(); 551 552 /* Screen off */ 553 if (lps0_dsm_func_mask > 0) 554 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 555 ACPI_LPS0_SCREEN_OFF_AMD : 556 ACPI_LPS0_SCREEN_OFF, 557 lps0_dsm_func_mask, lps0_dsm_guid); 558 559 if (lps0_dsm_func_mask_microsoft > 0) 560 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF, 561 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 562 563 /* LPS0 entry */ 564 if (lps0_dsm_func_mask > 0 && acpi_s2idle_vendor_amd()) 565 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY_AMD, 566 lps0_dsm_func_mask, lps0_dsm_guid); 567 568 if (lps0_dsm_func_mask_microsoft > 0) { 569 /* Modern Standby entry */ 570 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY, 571 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 572 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY, 573 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 574 } 575 576 if (lps0_dsm_func_mask > 0 && !acpi_s2idle_vendor_amd()) 577 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY, 578 lps0_dsm_func_mask, lps0_dsm_guid); 579 580 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) { 581 if (handler->prepare) 582 handler->prepare(); 583 } 584 585 return 0; 586} 587 588void acpi_s2idle_check(void) 589{ 590 struct acpi_s2idle_dev_ops *handler; 591 592 if (!lps0_device_handle || sleep_no_lps0) 593 return; 594 595 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) { 596 if (handler->check) 597 handler->check(); 598 } 599} 600 601void acpi_s2idle_restore_early(void) 602{ 603 struct acpi_s2idle_dev_ops *handler; 604 605 if (!lps0_device_handle || sleep_no_lps0) 606 return; 607 608 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) 609 if (handler->restore) 610 handler->restore(); 611 612 /* LPS0 exit */ 613 if (lps0_dsm_func_mask > 0) 614 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 615 ACPI_LPS0_EXIT_AMD : 616 ACPI_LPS0_EXIT, 617 lps0_dsm_func_mask, lps0_dsm_guid); 618 619 if (lps0_dsm_func_mask_microsoft > 0) { 620 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT, 621 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 622 /* Modern Standby exit */ 623 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT, 624 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 625 } 626 627 /* Screen on */ 628 if (lps0_dsm_func_mask_microsoft > 0) 629 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON, 630 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 631 if (lps0_dsm_func_mask > 0) 632 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 633 ACPI_LPS0_SCREEN_ON_AMD : 634 ACPI_LPS0_SCREEN_ON, 635 lps0_dsm_func_mask, lps0_dsm_guid); 636} 637 638static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = { 639 .begin = acpi_s2idle_begin, 640 .prepare = acpi_s2idle_prepare, 641 .prepare_late = acpi_s2idle_prepare_late, 642 .check = acpi_s2idle_check, 643 .wake = acpi_s2idle_wake, 644 .restore_early = acpi_s2idle_restore_early, 645 .restore = acpi_s2idle_restore, 646 .end = acpi_s2idle_end, 647}; 648 649void __init acpi_s2idle_setup(void) 650{ 651 acpi_scan_add_handler(&lps0_handler); 652 s2idle_set_ops(&acpi_s2idle_ops_lps0); 653} 654 655int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg) 656{ 657 unsigned int sleep_flags; 658 659 if (!lps0_device_handle || sleep_no_lps0) 660 return -ENODEV; 661 662 sleep_flags = lock_system_sleep(); 663 list_add(&arg->list_node, &lps0_s2idle_devops_head); 664 unlock_system_sleep(sleep_flags); 665 666 return 0; 667} 668EXPORT_SYMBOL_GPL(acpi_register_lps0_dev); 669 670void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg) 671{ 672 unsigned int sleep_flags; 673 674 if (!lps0_device_handle || sleep_no_lps0) 675 return; 676 677 sleep_flags = lock_system_sleep(); 678 list_del(&arg->list_node); 679 unlock_system_sleep(sleep_flags); 680} 681EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev); 682 683#endif /* CONFIG_SUSPEND */ 684