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 #define for_each_lpi_constraint(entry) \ 98 for (int i = 0; \ 99 entry = &lpi_constraints_table[i], i < lpi_constraints_table_size; \ 100 i++) 101 102 static 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"); 187 188 free_acpi_buffer: 189 ACPI_FREE(out_obj); 190 } 191 192 static 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"); 297 298 free_acpi_buffer: 299 ACPI_FREE(out_obj); 300 } 301 302 static void lpi_check_constraints(void) 303 { 304 struct lpi_constraints *entry; 305 306 if (IS_ERR_OR_NULL(lpi_constraints_table)) 307 return; 308 309 for_each_lpi_constraint(entry) { 310 struct acpi_device *adev = acpi_fetch_acpi_dev(entry->handle); 311 312 if (!adev) 313 continue; 314 315 acpi_handle_debug(entry->handle, 316 "LPI: required min power state:%s current power state:%s\n", 317 acpi_power_state_string(entry->min_dstate), 318 acpi_power_state_string(adev->power.state)); 319 320 if (!adev->flags.power_manageable) { 321 acpi_handle_info(entry->handle, "LPI: Device not power manageable\n"); 322 entry->handle = NULL; 323 continue; 324 } 325 326 if (adev->power.state < entry->min_dstate) 327 acpi_handle_info(entry->handle, 328 "LPI: Constraint not met; min power state:%s current power state:%s\n", 329 acpi_power_state_string(entry->min_dstate), 330 acpi_power_state_string(adev->power.state)); 331 } 332 } 333 334 static bool acpi_s2idle_vendor_amd(void) 335 { 336 return boot_cpu_data.x86_vendor == X86_VENDOR_AMD; 337 } 338 339 static const char *acpi_sleep_dsm_state_to_str(unsigned int state) 340 { 341 if (lps0_dsm_func_mask_microsoft || !acpi_s2idle_vendor_amd()) { 342 switch (state) { 343 case ACPI_LPS0_SCREEN_OFF: 344 return "screen off"; 345 case ACPI_LPS0_SCREEN_ON: 346 return "screen on"; 347 case ACPI_LPS0_ENTRY: 348 return "lps0 entry"; 349 case ACPI_LPS0_EXIT: 350 return "lps0 exit"; 351 case ACPI_LPS0_MS_ENTRY: 352 return "lps0 ms entry"; 353 case ACPI_LPS0_MS_EXIT: 354 return "lps0 ms exit"; 355 } 356 } else { 357 switch (state) { 358 case ACPI_LPS0_SCREEN_ON_AMD: 359 return "screen on"; 360 case ACPI_LPS0_SCREEN_OFF_AMD: 361 return "screen off"; 362 case ACPI_LPS0_ENTRY_AMD: 363 return "lps0 entry"; 364 case ACPI_LPS0_EXIT_AMD: 365 return "lps0 exit"; 366 } 367 } 368 369 return "unknown"; 370 } 371 372 static void acpi_sleep_run_lps0_dsm(unsigned int func, unsigned int func_mask, guid_t dsm_guid) 373 { 374 union acpi_object *out_obj; 375 376 if (!(func_mask & (1 << func))) 377 return; 378 379 out_obj = acpi_evaluate_dsm(lps0_device_handle, &dsm_guid, 380 rev_id, func, NULL); 381 ACPI_FREE(out_obj); 382 383 lps0_dsm_state = func; 384 if (pm_debug_messages_on) { 385 acpi_handle_info(lps0_device_handle, 386 "%s transitioned to state %s\n", 387 out_obj ? "Successfully" : "Failed to", 388 acpi_sleep_dsm_state_to_str(lps0_dsm_state)); 389 } 390 } 391 392 393 static int validate_dsm(acpi_handle handle, const char *uuid, int rev, guid_t *dsm_guid) 394 { 395 union acpi_object *obj; 396 int ret = -EINVAL; 397 398 guid_parse(uuid, dsm_guid); 399 400 /* Check if the _DSM is present and as expected. */ 401 obj = acpi_evaluate_dsm_typed(handle, dsm_guid, rev, 0, NULL, ACPI_TYPE_BUFFER); 402 if (!obj || obj->buffer.length == 0 || obj->buffer.length > sizeof(u32)) { 403 acpi_handle_debug(handle, 404 "_DSM UUID %s rev %d function 0 evaluation failed\n", uuid, rev); 405 goto out; 406 } 407 408 ret = *(int *)obj->buffer.pointer; 409 acpi_handle_debug(handle, "_DSM UUID %s rev %d function mask: 0x%x\n", uuid, rev, ret); 410 411 out: 412 ACPI_FREE(obj); 413 return ret; 414 } 415 416 struct amd_lps0_hid_device_data { 417 const bool check_off_by_one; 418 }; 419 420 static const struct amd_lps0_hid_device_data amd_picasso = { 421 .check_off_by_one = true, 422 }; 423 424 static const struct amd_lps0_hid_device_data amd_cezanne = { 425 .check_off_by_one = false, 426 }; 427 428 static const struct acpi_device_id amd_hid_ids[] = { 429 {"AMD0004", (kernel_ulong_t)&amd_picasso, }, 430 {"AMD0005", (kernel_ulong_t)&amd_picasso, }, 431 {"AMDI0005", (kernel_ulong_t)&amd_picasso, }, 432 {"AMDI0006", (kernel_ulong_t)&amd_cezanne, }, 433 {} 434 }; 435 436 static int lps0_device_attach(struct acpi_device *adev, 437 const struct acpi_device_id *not_used) 438 { 439 if (lps0_device_handle) 440 return 0; 441 442 lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle, 443 ACPI_LPS0_DSM_UUID_MICROSOFT, 0, 444 &lps0_dsm_guid_microsoft); 445 if (acpi_s2idle_vendor_amd()) { 446 static const struct acpi_device_id *dev_id; 447 const struct amd_lps0_hid_device_data *data; 448 449 for (dev_id = &amd_hid_ids[0]; dev_id->id[0]; dev_id++) 450 if (acpi_dev_hid_uid_match(adev, dev_id->id, NULL)) 451 break; 452 if (dev_id->id[0]) 453 data = (const struct amd_lps0_hid_device_data *) dev_id->driver_data; 454 else 455 data = &amd_cezanne; 456 lps0_dsm_func_mask = validate_dsm(adev->handle, 457 ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid); 458 if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) { 459 lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1; 460 acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n", 461 ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask); 462 } else if (lps0_dsm_func_mask_microsoft > 0 && rev_id) { 463 lps0_dsm_func_mask_microsoft = -EINVAL; 464 acpi_handle_debug(adev->handle, "_DSM Using AMD method\n"); 465 } 466 } else { 467 rev_id = 1; 468 lps0_dsm_func_mask = validate_dsm(adev->handle, 469 ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid); 470 if (lps0_dsm_func_mask > 0 && lps0_dsm_func_mask_microsoft > 0) { 471 unsigned int func_mask; 472 473 /* 474 * Log a message if the _DSM function sets for two 475 * different UUIDs overlap. 476 */ 477 func_mask = lps0_dsm_func_mask & lps0_dsm_func_mask_microsoft; 478 if (func_mask) 479 acpi_handle_info(adev->handle, 480 "Duplicate LPS0 _DSM functions (mask: 0x%x)\n", 481 func_mask); 482 } 483 } 484 485 if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0) 486 return 0; //function evaluation failed 487 488 lps0_device_handle = adev->handle; 489 490 /* 491 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in 492 * the FADT and the default suspend mode was not set from the command 493 * line. 494 */ 495 if ((acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0) && 496 mem_sleep_default > PM_SUSPEND_MEM && !acpi_sleep_default_s3) { 497 mem_sleep_current = PM_SUSPEND_TO_IDLE; 498 pr_info("Low-power S0 idle used by default for system suspend\n"); 499 } 500 501 /* 502 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the 503 * EC GPE to be enabled while suspended for certain wakeup devices to 504 * work, so mark it as wakeup-capable. 505 */ 506 acpi_ec_mark_gpe_for_wake(); 507 508 return 0; 509 } 510 511 static struct acpi_scan_handler lps0_handler = { 512 .ids = lps0_device_ids, 513 .attach = lps0_device_attach, 514 }; 515 516 static int acpi_s2idle_begin_lps0(void) 517 { 518 if (pm_debug_messages_on && !lpi_constraints_table) { 519 if (acpi_s2idle_vendor_amd()) 520 lpi_device_get_constraints_amd(); 521 else 522 lpi_device_get_constraints(); 523 524 /* 525 * Try to retrieve the constraints only once because failures 526 * to do so usually are sticky. 527 */ 528 if (!lpi_constraints_table) 529 lpi_constraints_table = ERR_PTR(-ENODATA); 530 } 531 532 return acpi_s2idle_begin(); 533 } 534 535 static int acpi_s2idle_prepare_late_lps0(void) 536 { 537 struct acpi_s2idle_dev_ops *handler; 538 539 if (!lps0_device_handle || sleep_no_lps0) 540 return 0; 541 542 if (pm_debug_messages_on) 543 lpi_check_constraints(); 544 545 /* Screen off */ 546 if (lps0_dsm_func_mask > 0) 547 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 548 ACPI_LPS0_SCREEN_OFF_AMD : 549 ACPI_LPS0_SCREEN_OFF, 550 lps0_dsm_func_mask, lps0_dsm_guid); 551 552 if (lps0_dsm_func_mask_microsoft > 0) 553 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF, 554 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 555 556 /* LPS0 entry */ 557 if (lps0_dsm_func_mask > 0 && acpi_s2idle_vendor_amd()) 558 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY_AMD, 559 lps0_dsm_func_mask, lps0_dsm_guid); 560 561 if (lps0_dsm_func_mask_microsoft > 0) { 562 /* Modern Standby entry */ 563 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_ENTRY, 564 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 565 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY, 566 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 567 } 568 569 if (lps0_dsm_func_mask > 0 && !acpi_s2idle_vendor_amd()) 570 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY, 571 lps0_dsm_func_mask, lps0_dsm_guid); 572 573 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) { 574 if (handler->prepare) 575 handler->prepare(); 576 } 577 578 return 0; 579 } 580 581 static void acpi_s2idle_check_lps0(void) 582 { 583 struct acpi_s2idle_dev_ops *handler; 584 585 if (!lps0_device_handle || sleep_no_lps0) 586 return; 587 588 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) { 589 if (handler->check) 590 handler->check(); 591 } 592 } 593 594 static void acpi_s2idle_restore_early_lps0(void) 595 { 596 struct acpi_s2idle_dev_ops *handler; 597 598 if (!lps0_device_handle || sleep_no_lps0) 599 return; 600 601 list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) 602 if (handler->restore) 603 handler->restore(); 604 605 /* LPS0 exit */ 606 if (lps0_dsm_func_mask > 0) 607 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 608 ACPI_LPS0_EXIT_AMD : 609 ACPI_LPS0_EXIT, 610 lps0_dsm_func_mask, lps0_dsm_guid); 611 612 if (lps0_dsm_func_mask_microsoft > 0) { 613 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT, 614 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 615 /* Modern Standby exit */ 616 acpi_sleep_run_lps0_dsm(ACPI_LPS0_MS_EXIT, 617 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 618 } 619 620 /* Screen on */ 621 if (lps0_dsm_func_mask_microsoft > 0) 622 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON, 623 lps0_dsm_func_mask_microsoft, lps0_dsm_guid_microsoft); 624 if (lps0_dsm_func_mask > 0) 625 acpi_sleep_run_lps0_dsm(acpi_s2idle_vendor_amd() ? 626 ACPI_LPS0_SCREEN_ON_AMD : 627 ACPI_LPS0_SCREEN_ON, 628 lps0_dsm_func_mask, lps0_dsm_guid); 629 } 630 631 static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = { 632 .begin = acpi_s2idle_begin_lps0, 633 .prepare = acpi_s2idle_prepare, 634 .prepare_late = acpi_s2idle_prepare_late_lps0, 635 .check = acpi_s2idle_check_lps0, 636 .wake = acpi_s2idle_wake, 637 .restore_early = acpi_s2idle_restore_early_lps0, 638 .restore = acpi_s2idle_restore, 639 .end = acpi_s2idle_end, 640 }; 641 642 void __init acpi_s2idle_setup(void) 643 { 644 acpi_scan_add_handler(&lps0_handler); 645 s2idle_set_ops(&acpi_s2idle_ops_lps0); 646 } 647 648 int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg) 649 { 650 unsigned int sleep_flags; 651 652 if (!lps0_device_handle || sleep_no_lps0) 653 return -ENODEV; 654 655 sleep_flags = lock_system_sleep(); 656 list_add(&arg->list_node, &lps0_s2idle_devops_head); 657 unlock_system_sleep(sleep_flags); 658 659 return 0; 660 } 661 EXPORT_SYMBOL_GPL(acpi_register_lps0_dev); 662 663 void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg) 664 { 665 unsigned int sleep_flags; 666 667 if (!lps0_device_handle || sleep_no_lps0) 668 return; 669 670 sleep_flags = lock_system_sleep(); 671 list_del(&arg->list_node); 672 unlock_system_sleep(sleep_flags); 673 } 674 EXPORT_SYMBOL_GPL(acpi_unregister_lps0_dev); 675 676 #endif /* CONFIG_SUSPEND */ 677