drivers/acpi/hardware/hwsleep.c

   1
   2 /******************************************************************************
   3  *
   4  * Name: hwsleep.c - ACPI Hardware Sleep/Wake Interface
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2007, R. Byron Moore
  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 <acpi/actables.h>
  47
  48 #define _COMPONENT          ACPI_HARDWARE
  49 ACPI_MODULE_NAME("hwsleep")
  50
  51 /*******************************************************************************
  52  *
  53  * FUNCTION:    acpi_set_firmware_waking_vector
  54  *
  55  * PARAMETERS:  physical_address    - Physical address of ACPI real mode
  56  *                                    entry point.
  57  *
  58  * RETURN:      Status
  59  *
  60  * DESCRIPTION: Access function for the firmware_waking_vector field in FACS
  61  *
  62  ******************************************************************************/
  63 acpi_status
  64 acpi_set_firmware_waking_vector(acpi_physical_address physical_address)
  65 {
  66         struct acpi_table_facs *facs;
  67         acpi_status status;
  68
  69         ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector);
  70
  71         /* Get the FACS */
  72
  73         status =
  74             acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
  75                                     (struct acpi_table_header **)&facs);
  76         if (ACPI_FAILURE(status)) {
  77                 return_ACPI_STATUS(status);
  78         }
  79
  80         /* Set the vector */
  81
  82         if ((facs->length < 32) || (!(facs->xfirmware_waking_vector))) {
  83                 /*
  84                  * ACPI 1.0 FACS or short table or optional X_ field is zero
  85                  */
  86                 facs->firmware_waking_vector = (u32) physical_address;
  87         } else {
  88                 /*
  89                  * ACPI 2.0 FACS with valid X_ field
  90                  */
  91                 facs->xfirmware_waking_vector = physical_address;
  92         }
  93
  94         return_ACPI_STATUS(AE_OK);
  95 }
  96
  97 ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector)
  98
  99 /*******************************************************************************
 100  *
 101  * FUNCTION:    acpi_get_firmware_waking_vector
 102  *
 103  * PARAMETERS:  *physical_address   - Where the contents of
 104  *                                    the firmware_waking_vector field of
 105  *                                    the FACS will be returned.
 106  *
 107  * RETURN:      Status, vector
 108  *
 109  * DESCRIPTION: Access function for the firmware_waking_vector field in FACS
 110  *
 111  ******************************************************************************/
 112 #ifdef ACPI_FUTURE_USAGE
 113 acpi_status
 114 acpi_get_firmware_waking_vector(acpi_physical_address * physical_address)
 115 {
 116         struct acpi_table_facs *facs;
 117         acpi_status status;
 118
 119         ACPI_FUNCTION_TRACE(acpi_get_firmware_waking_vector);
 120
 121         if (!physical_address) {
 122                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 123         }
 124
 125         /* Get the FACS */
 126
 127         status =
 128             acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
 129                                     (struct acpi_table_header **)&facs);
 130         if (ACPI_FAILURE(status)) {
 131                 return_ACPI_STATUS(status);
 132         }
 133
 134         /* Get the vector */
 135
 136         if ((facs->length < 32) || (!(facs->xfirmware_waking_vector))) {
 137                 /*
 138                  * ACPI 1.0 FACS or short table or optional X_ field is zero
 139                  */
 140                 *physical_address =
 141                     (acpi_physical_address) facs->firmware_waking_vector;
 142         } else {
 143                 /*
 144                  * ACPI 2.0 FACS with valid X_ field
 145                  */
 146                 *physical_address =
 147                     (acpi_physical_address) facs->xfirmware_waking_vector;
 148         }
 149
 150         return_ACPI_STATUS(AE_OK);
 151 }
 152
 153 ACPI_EXPORT_SYMBOL(acpi_get_firmware_waking_vector)
 154 #endif
 155 /*******************************************************************************
 156  *
 157  * FUNCTION:    acpi_enter_sleep_state_prep
 158  *
 159  * PARAMETERS:  sleep_state         - Which sleep state to enter
 160  *
 161  * RETURN:      Status
 162  *
 163  * DESCRIPTION: Prepare to enter a system sleep state (see ACPI 2.0 spec p 231)
 164  *              This function must execute with interrupts enabled.
 165  *              We break sleeping into 2 stages so that OSPM can handle
 166  *              various OS-specific tasks between the two steps.
 167  *
 168  ******************************************************************************/
 169 acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)
 170 {
 171         acpi_status status;
 172         struct acpi_object_list arg_list;
 173         union acpi_object arg;
 174
 175         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_prep);
 176
 177         /*
 178          * _PSW methods could be run here to enable wake-on keyboard, LAN, etc.
 179          */
 180         status = acpi_get_sleep_type_data(sleep_state,
 181                                           &acpi_gbl_sleep_type_a,
 182                                           &acpi_gbl_sleep_type_b);
 183         if (ACPI_FAILURE(status)) {
 184                 return_ACPI_STATUS(status);
 185         }
 186
 187         /* Setup parameter object */
 188
 189         arg_list.count = 1;
 190         arg_list.pointer = &arg;
 191
 192         arg.type = ACPI_TYPE_INTEGER;
 193         arg.integer.value = sleep_state;
 194
 195         /* Run the _PTS method */
 196
 197         status = acpi_evaluate_object(NULL, METHOD_NAME__PTS, &arg_list, NULL);
 198         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 199                 return_ACPI_STATUS(status);
 200         }
 201
 202         /* Setup the argument to _SST */
 203
 204         switch (sleep_state) {
 205         case ACPI_STATE_S0:
 206                 arg.integer.value = ACPI_SST_WORKING;
 207                 break;
 208
 209         case ACPI_STATE_S1:
 210         case ACPI_STATE_S2:
 211         case ACPI_STATE_S3:
 212                 arg.integer.value = ACPI_SST_SLEEPING;
 213                 break;
 214
 215         case ACPI_STATE_S4:
 216                 arg.integer.value = ACPI_SST_SLEEP_CONTEXT;
 217                 break;
 218
 219         default:
 220                 arg.integer.value = ACPI_SST_INDICATOR_OFF;     /* Default is off */
 221                 break;
 222         }
 223
 224         /* Set the system indicators to show the desired sleep state. */
 225
 226         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 227         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 228                 ACPI_EXCEPTION((AE_INFO, status,
 229                                 "While executing method _SST"));
 230         }
 231
 232         /* Disable/Clear all GPEs */
 233
 234         status = acpi_hw_disable_all_gpes();
 235
 236         return_ACPI_STATUS(status);
 237 }
 238
 239 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
 240
 241 /*******************************************************************************
 242  *
 243  * FUNCTION:    acpi_enter_sleep_state
 244  *
 245  * PARAMETERS:  sleep_state         - Which sleep state to enter
 246  *
 247  * RETURN:      Status
 248  *
 249  * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
 250  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 251  *
 252  ******************************************************************************/
 253 acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 254 {
 255         u32 PM1Acontrol;
 256         u32 PM1Bcontrol;
 257         struct acpi_bit_register_info *sleep_type_reg_info;
 258         struct acpi_bit_register_info *sleep_enable_reg_info;
 259         u32 in_value;
 260         struct acpi_object_list arg_list;
 261         union acpi_object arg;
 262         acpi_status status;
 263
 264         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state);
 265
 266         if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
 267             (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
 268                 ACPI_ERROR((AE_INFO, "Sleep values out of range: A=%X B=%X",
 269                             acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
 270                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 271         }
 272
 273         sleep_type_reg_info =
 274             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 275         sleep_enable_reg_info =
 276             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 277
 278         /* Clear wake status */
 279
 280         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 281         if (ACPI_FAILURE(status)) {
 282                 return_ACPI_STATUS(status);
 283         }
 284
 285         /* Clear all fixed and general purpose status bits */
 286
 287         status = acpi_hw_clear_acpi_status();
 288         if (ACPI_FAILURE(status)) {
 289                 return_ACPI_STATUS(status);
 290         }
 291
 292         /*
 293          * 2) Enable all wakeup GPEs
 294          */
 295         status = acpi_hw_disable_all_gpes();
 296         if (ACPI_FAILURE(status)) {
 297                 return_ACPI_STATUS(status);
 298         }
 299
 300         acpi_gbl_system_awake_and_running = FALSE;
 301
 302         status = acpi_hw_enable_all_wakeup_gpes();
 303         if (ACPI_FAILURE(status)) {
 304                 return_ACPI_STATUS(status);
 305         }
 306
 307         /* Execute the _GTS method */
 308
 309         arg_list.count = 1;
 310         arg_list.pointer = &arg;
 311         arg.type = ACPI_TYPE_INTEGER;
 312         arg.integer.value = sleep_state;
 313
 314         status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
 315         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 316                 return_ACPI_STATUS(status);
 317         }
 318
 319         /* Get current value of PM1A control */
 320
 321         status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol);
 322         if (ACPI_FAILURE(status)) {
 323                 return_ACPI_STATUS(status);
 324         }
 325         ACPI_DEBUG_PRINT((ACPI_DB_INIT,
 326                           "Entering sleep state [S%d]\n", sleep_state));
 327
 328         /* Clear SLP_EN and SLP_TYP fields */
 329
 330         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 331                          sleep_enable_reg_info->access_bit_mask);
 332         PM1Bcontrol = PM1Acontrol;
 333
 334         /* Insert SLP_TYP bits */
 335
 336         PM1Acontrol |=
 337             (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 338         PM1Bcontrol |=
 339             (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
 340
 341         /*
 342          * We split the writes of SLP_TYP and SLP_EN to workaround
 343          * poorly implemented hardware.
 344          */
 345
 346         /* Write #1: fill in SLP_TYP data */
 347
 348         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 349                                         PM1Acontrol);
 350         if (ACPI_FAILURE(status)) {
 351                 return_ACPI_STATUS(status);
 352         }
 353
 354         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 355                                         PM1Bcontrol);
 356         if (ACPI_FAILURE(status)) {
 357                 return_ACPI_STATUS(status);
 358         }
 359
 360         /* Insert SLP_ENABLE bit */
 361
 362         PM1Acontrol |= sleep_enable_reg_info->access_bit_mask;
 363         PM1Bcontrol |= sleep_enable_reg_info->access_bit_mask;
 364
 365         /* Write #2: SLP_TYP + SLP_EN */
 366
 367         ACPI_FLUSH_CPU_CACHE();
 368
 369         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 370                                         PM1Acontrol);
 371         if (ACPI_FAILURE(status)) {
 372                 return_ACPI_STATUS(status);
 373         }
 374
 375         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 376                                         PM1Bcontrol);
 377         if (ACPI_FAILURE(status)) {
 378                 return_ACPI_STATUS(status);
 379         }
 380
 381         if (sleep_state > ACPI_STATE_S3) {
 382                 /*
 383                  * We wanted to sleep > S3, but it didn't happen (by virtue of the
 384                  * fact that we are still executing!)
 385                  *
 386                  * Wait ten seconds, then try again. This is to get S4/S5 to work on
 387                  * all machines.
 388                  *
 389                  * We wait so long to allow chipsets that poll this reg very slowly to
 390                  * still read the right value. Ideally, this block would go
 391                  * away entirely.
 392                  */
 393                 acpi_os_stall(10000000);
 394
 395                 status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
 396                                                 sleep_enable_reg_info->
 397                                                 access_bit_mask);
 398                 if (ACPI_FAILURE(status)) {
 399                         return_ACPI_STATUS(status);
 400                 }
 401         }
 402
 403         /* Wait until we enter sleep state */
 404
 405         do {
 406                 status = acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS,
 407                                                     &in_value);
 408                 if (ACPI_FAILURE(status)) {
 409                         return_ACPI_STATUS(status);
 410                 }
 411
 412                 /* Spin until we wake */
 413
 414         } while (!in_value);
 415
 416         return_ACPI_STATUS(AE_OK);
 417 }
 418
 419 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state)
 420
 421 /*******************************************************************************
 422  *
 423  * FUNCTION:    acpi_enter_sleep_state_s4bios
 424  *
 425  * PARAMETERS:  None
 426  *
 427  * RETURN:      Status
 428  *
 429  * DESCRIPTION: Perform a S4 bios request.
 430  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 431  *
 432  ******************************************************************************/
 433 acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void)
 434 {
 435         u32 in_value;
 436         acpi_status status;
 437
 438         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_s4bios);
 439
 440         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 441         if (ACPI_FAILURE(status)) {
 442                 return_ACPI_STATUS(status);
 443         }
 444
 445         status = acpi_hw_clear_acpi_status();
 446         if (ACPI_FAILURE(status)) {
 447                 return_ACPI_STATUS(status);
 448         }
 449
 450         /*
 451          * 1) Disable/Clear all GPEs
 452          * 2) Enable all wakeup GPEs
 453          */
 454         status = acpi_hw_disable_all_gpes();
 455         if (ACPI_FAILURE(status)) {
 456                 return_ACPI_STATUS(status);
 457         }
 458         acpi_gbl_system_awake_and_running = FALSE;
 459
 460         status = acpi_hw_enable_all_wakeup_gpes();
 461         if (ACPI_FAILURE(status)) {
 462                 return_ACPI_STATUS(status);
 463         }
 464
 465         ACPI_FLUSH_CPU_CACHE();
 466
 467         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 468                                     (u32) acpi_gbl_FADT.S4bios_request, 8);
 469
 470         do {
 471                 acpi_os_stall(1000);
 472                 status = acpi_get_register(ACPI_BITREG_WAKE_STATUS, &in_value);
 473                 if (ACPI_FAILURE(status)) {
 474                         return_ACPI_STATUS(status);
 475                 }
 476         } while (!in_value);
 477
 478         return_ACPI_STATUS(AE_OK);
 479 }
 480
 481 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_s4bios)
 482
 483 /*******************************************************************************
 484  *
 485  * FUNCTION:    acpi_leave_sleep_state_prep
 486  *
 487  * PARAMETERS:  sleep_state         - Which sleep state we are exiting
 488  *
 489  * RETURN:      Status
 490  *
 491  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
 492  *              sleep.
 493  *              Called with interrupts DISABLED.
 494  *
 495  ******************************************************************************/
 496 acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
 497 {
 498         struct acpi_object_list arg_list;
 499         union acpi_object arg;
 500         acpi_status status;
 501         struct acpi_bit_register_info *sleep_type_reg_info;
 502         struct acpi_bit_register_info *sleep_enable_reg_info;
 503         u32 PM1Acontrol;
 504         u32 PM1Bcontrol;
 505
 506         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state_prep);
 507
 508         /*
 509          * Set SLP_TYPE and SLP_EN to state S0.
 510          * This is unclear from the ACPI Spec, but it is required
 511          * by some machines.
 512          */
 513         status = acpi_get_sleep_type_data(ACPI_STATE_S0,
 514                                           &acpi_gbl_sleep_type_a,
 515                                           &acpi_gbl_sleep_type_b);
 516         if (ACPI_SUCCESS(status)) {
 517                 sleep_type_reg_info =
 518                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 519                 sleep_enable_reg_info =
 520                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 521
 522                 /* Get current value of PM1A control */
 523
 524                 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 525                                                &PM1Acontrol);
 526                 if (ACPI_SUCCESS(status)) {
 527
 528                         /* Clear SLP_EN and SLP_TYP fields */
 529
 530                         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 531                                          sleep_enable_reg_info->
 532                                          access_bit_mask);
 533                         PM1Bcontrol = PM1Acontrol;
 534
 535                         /* Insert SLP_TYP bits */
 536
 537                         PM1Acontrol |=
 538                             (acpi_gbl_sleep_type_a << sleep_type_reg_info->
 539                              bit_position);
 540                         PM1Bcontrol |=
 541                             (acpi_gbl_sleep_type_b << sleep_type_reg_info->
 542                              bit_position);
 543
 544                         /* Just ignore any errors */
 545
 546                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 547                                                      PM1Acontrol);
 548                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 549                                                      PM1Bcontrol);
 550                 }
 551         }
 552
 553         /* Execute the _BFS method */
 554
 555         arg_list.count = 1;
 556         arg_list.pointer = &arg;
 557         arg.type = ACPI_TYPE_INTEGER;
 558         arg.integer.value = sleep_state;
 559
 560         status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
 561         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 562                 ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
 563         }
 564
 565         return_ACPI_STATUS(status);
 566 }
 567
 568 /*******************************************************************************
 569  *
 570  * FUNCTION:    acpi_leave_sleep_state
 571  *
 572  * PARAMETERS:  sleep_state         - Which sleep state we just exited
 573  *
 574  * RETURN:      Status
 575  *
 576  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 577  *              Called with interrupts ENABLED.
 578  *
 579  ******************************************************************************/
 580 acpi_status acpi_leave_sleep_state(u8 sleep_state)
 581 {
 582         struct acpi_object_list arg_list;
 583         union acpi_object arg;
 584         acpi_status status;
 585
 586         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state);
 587
 588         /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
 589
 590         acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 591
 592         /* Setup parameter object */
 593
 594         arg_list.count = 1;
 595         arg_list.pointer = &arg;
 596         arg.type = ACPI_TYPE_INTEGER;
 597
 598         /* Ignore any errors from these methods */
 599
 600         arg.integer.value = ACPI_SST_WAKING;
 601         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 602         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 603                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 604         }
 605
 606         /*
 607          * GPEs must be enabled before _WAK is called as GPEs
 608          * might get fired there
 609          *
 610          * Restore the GPEs:
 611          * 1) Disable/Clear all GPEs
 612          * 2) Enable all runtime GPEs
 613          */
 614         status = acpi_hw_disable_all_gpes();
 615         if (ACPI_FAILURE(status)) {
 616                 return_ACPI_STATUS(status);
 617         }
 618         status = acpi_hw_enable_all_runtime_gpes();
 619         if (ACPI_FAILURE(status)) {
 620                 return_ACPI_STATUS(status);
 621         }
 622
 623         status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
 624         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 625                 ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
 626         }
 627         /* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 628
 629         acpi_gbl_system_awake_and_running = TRUE;
 630
 631         /* Enable power button */
 632
 633         (void)
 634             acpi_set_register(acpi_gbl_fixed_event_info
 635                               [ACPI_EVENT_POWER_BUTTON].enable_register_id, 1);
 636
 637         (void)
 638             acpi_set_register(acpi_gbl_fixed_event_info
 639                               [ACPI_EVENT_POWER_BUTTON].status_register_id, 1);
 640
 641         arg.integer.value = ACPI_SST_WORKING;
 642         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 643         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 644                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 645         }
 646
 647         return_ACPI_STATUS(status);
 648 }
 649
 650 ACPI_EXPORT_SYMBOL(acpi_leave_sleep_state)