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         return_ACPI_STATUS(status);
 233 }
 234
 235 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
 236
 237 /*******************************************************************************
 238  *
 239  * FUNCTION:    acpi_enter_sleep_state
 240  *
 241  * PARAMETERS:  sleep_state         - Which sleep state to enter
 242  *
 243  * RETURN:      Status
 244  *
 245  * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
 246  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 247  *
 248  ******************************************************************************/
 249 acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 250 {
 251         u32 PM1Acontrol;
 252         u32 PM1Bcontrol;
 253         struct acpi_bit_register_info *sleep_type_reg_info;
 254         struct acpi_bit_register_info *sleep_enable_reg_info;
 255         u32 in_value;
 256         struct acpi_object_list arg_list;
 257         union acpi_object arg;
 258         acpi_status status;
 259
 260         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state);
 261
 262         if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
 263             (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
 264                 ACPI_ERROR((AE_INFO, "Sleep values out of range: A=%X B=%X",
 265                             acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
 266                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 267         }
 268
 269         sleep_type_reg_info =
 270             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 271         sleep_enable_reg_info =
 272             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 273
 274         /* Clear wake status */
 275
 276         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 277         if (ACPI_FAILURE(status)) {
 278                 return_ACPI_STATUS(status);
 279         }
 280
 281         /* Clear all fixed and general purpose status bits */
 282
 283         status = acpi_hw_clear_acpi_status();
 284         if (ACPI_FAILURE(status)) {
 285                 return_ACPI_STATUS(status);
 286         }
 287
 288         /*
 289          * 2) Enable all wakeup GPEs
 290          */
 291         status = acpi_hw_disable_all_gpes();
 292         if (ACPI_FAILURE(status)) {
 293                 return_ACPI_STATUS(status);
 294         }
 295
 296         acpi_gbl_system_awake_and_running = FALSE;
 297
 298         status = acpi_hw_enable_all_wakeup_gpes();
 299         if (ACPI_FAILURE(status)) {
 300                 return_ACPI_STATUS(status);
 301         }
 302
 303         /* Execute the _GTS method */
 304
 305         arg_list.count = 1;
 306         arg_list.pointer = &arg;
 307         arg.type = ACPI_TYPE_INTEGER;
 308         arg.integer.value = sleep_state;
 309
 310         status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
 311         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 312                 return_ACPI_STATUS(status);
 313         }
 314
 315         /* Get current value of PM1A control */
 316
 317         status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol);
 318         if (ACPI_FAILURE(status)) {
 319                 return_ACPI_STATUS(status);
 320         }
 321         ACPI_DEBUG_PRINT((ACPI_DB_INIT,
 322                           "Entering sleep state [S%d]\n", sleep_state));
 323
 324         /* Clear SLP_EN and SLP_TYP fields */
 325
 326         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 327                          sleep_enable_reg_info->access_bit_mask);
 328         PM1Bcontrol = PM1Acontrol;
 329
 330         /* Insert SLP_TYP bits */
 331
 332         PM1Acontrol |=
 333             (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 334         PM1Bcontrol |=
 335             (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
 336
 337         /*
 338          * We split the writes of SLP_TYP and SLP_EN to workaround
 339          * poorly implemented hardware.
 340          */
 341
 342         /* Write #1: fill in SLP_TYP data */
 343
 344         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 345                                         PM1Acontrol);
 346         if (ACPI_FAILURE(status)) {
 347                 return_ACPI_STATUS(status);
 348         }
 349
 350         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 351                                         PM1Bcontrol);
 352         if (ACPI_FAILURE(status)) {
 353                 return_ACPI_STATUS(status);
 354         }
 355
 356         /* Insert SLP_ENABLE bit */
 357
 358         PM1Acontrol |= sleep_enable_reg_info->access_bit_mask;
 359         PM1Bcontrol |= sleep_enable_reg_info->access_bit_mask;
 360
 361         /* Write #2: SLP_TYP + SLP_EN */
 362
 363         ACPI_FLUSH_CPU_CACHE();
 364
 365         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 366                                         PM1Acontrol);
 367         if (ACPI_FAILURE(status)) {
 368                 return_ACPI_STATUS(status);
 369         }
 370
 371         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 372                                         PM1Bcontrol);
 373         if (ACPI_FAILURE(status)) {
 374                 return_ACPI_STATUS(status);
 375         }
 376
 377         if (sleep_state > ACPI_STATE_S3) {
 378                 /*
 379                  * We wanted to sleep > S3, but it didn't happen (by virtue of the
 380                  * fact that we are still executing!)
 381                  *
 382                  * Wait ten seconds, then try again. This is to get S4/S5 to work on
 383                  * all machines.
 384                  *
 385                  * We wait so long to allow chipsets that poll this reg very slowly to
 386                  * still read the right value. Ideally, this block would go
 387                  * away entirely.
 388                  */
 389                 acpi_os_stall(10000000);
 390
 391                 status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
 392                                                 sleep_enable_reg_info->
 393                                                 access_bit_mask);
 394                 if (ACPI_FAILURE(status)) {
 395                         return_ACPI_STATUS(status);
 396                 }
 397         }
 398
 399         /* Wait until we enter sleep state */
 400
 401         do {
 402                 status = acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS,
 403                                                     &in_value);
 404                 if (ACPI_FAILURE(status)) {
 405                         return_ACPI_STATUS(status);
 406                 }
 407
 408                 /* Spin until we wake */
 409
 410         } while (!in_value);
 411
 412         return_ACPI_STATUS(AE_OK);
 413 }
 414
 415 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state)
 416
 417 /*******************************************************************************
 418  *
 419  * FUNCTION:    acpi_enter_sleep_state_s4bios
 420  *
 421  * PARAMETERS:  None
 422  *
 423  * RETURN:      Status
 424  *
 425  * DESCRIPTION: Perform a S4 bios request.
 426  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 427  *
 428  ******************************************************************************/
 429 acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void)
 430 {
 431         u32 in_value;
 432         acpi_status status;
 433
 434         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_s4bios);
 435
 436         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 437         if (ACPI_FAILURE(status)) {
 438                 return_ACPI_STATUS(status);
 439         }
 440
 441         status = acpi_hw_clear_acpi_status();
 442         if (ACPI_FAILURE(status)) {
 443                 return_ACPI_STATUS(status);
 444         }
 445
 446         /*
 447          * 1) Disable/Clear all GPEs
 448          * 2) Enable all wakeup GPEs
 449          */
 450         status = acpi_hw_disable_all_gpes();
 451         if (ACPI_FAILURE(status)) {
 452                 return_ACPI_STATUS(status);
 453         }
 454         acpi_gbl_system_awake_and_running = FALSE;
 455
 456         status = acpi_hw_enable_all_wakeup_gpes();
 457         if (ACPI_FAILURE(status)) {
 458                 return_ACPI_STATUS(status);
 459         }
 460
 461         ACPI_FLUSH_CPU_CACHE();
 462
 463         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 464                                     (u32) acpi_gbl_FADT.S4bios_request, 8);
 465
 466         do {
 467                 acpi_os_stall(1000);
 468                 status = acpi_get_register(ACPI_BITREG_WAKE_STATUS, &in_value);
 469                 if (ACPI_FAILURE(status)) {
 470                         return_ACPI_STATUS(status);
 471                 }
 472         } while (!in_value);
 473
 474         return_ACPI_STATUS(AE_OK);
 475 }
 476
 477 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_s4bios)
 478
 479 /*******************************************************************************
 480  *
 481  * FUNCTION:    acpi_leave_sleep_state_prep
 482  *
 483  * PARAMETERS:  sleep_state         - Which sleep state we are exiting
 484  *
 485  * RETURN:      Status
 486  *
 487  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
 488  *              sleep.
 489  *              Called with interrupts DISABLED.
 490  *
 491  ******************************************************************************/
 492 acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
 493 {
 494         struct acpi_object_list arg_list;
 495         union acpi_object arg;
 496         acpi_status status;
 497         struct acpi_bit_register_info *sleep_type_reg_info;
 498         struct acpi_bit_register_info *sleep_enable_reg_info;
 499         u32 PM1Acontrol;
 500         u32 PM1Bcontrol;
 501
 502         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state_prep);
 503
 504         /*
 505          * Set SLP_TYPE and SLP_EN to state S0.
 506          * This is unclear from the ACPI Spec, but it is required
 507          * by some machines.
 508          */
 509         status = acpi_get_sleep_type_data(ACPI_STATE_S0,
 510                                           &acpi_gbl_sleep_type_a,
 511                                           &acpi_gbl_sleep_type_b);
 512         if (ACPI_SUCCESS(status)) {
 513                 sleep_type_reg_info =
 514                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 515                 sleep_enable_reg_info =
 516                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 517
 518                 /* Get current value of PM1A control */
 519
 520                 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 521                                                &PM1Acontrol);
 522                 if (ACPI_SUCCESS(status)) {
 523
 524                         /* Clear SLP_EN and SLP_TYP fields */
 525
 526                         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 527                                          sleep_enable_reg_info->
 528                                          access_bit_mask);
 529                         PM1Bcontrol = PM1Acontrol;
 530
 531                         /* Insert SLP_TYP bits */
 532
 533                         PM1Acontrol |=
 534                             (acpi_gbl_sleep_type_a << sleep_type_reg_info->
 535                              bit_position);
 536                         PM1Bcontrol |=
 537                             (acpi_gbl_sleep_type_b << sleep_type_reg_info->
 538                              bit_position);
 539
 540                         /* Just ignore any errors */
 541
 542                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 543                                                      PM1Acontrol);
 544                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 545                                                      PM1Bcontrol);
 546                 }
 547         }
 548
 549         /* Execute the _BFS method */
 550
 551         arg_list.count = 1;
 552         arg_list.pointer = &arg;
 553         arg.type = ACPI_TYPE_INTEGER;
 554         arg.integer.value = sleep_state;
 555
 556         status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
 557         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 558                 ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
 559         }
 560
 561         return_ACPI_STATUS(status);
 562 }
 563
 564 /*******************************************************************************
 565  *
 566  * FUNCTION:    acpi_leave_sleep_state
 567  *
 568  * PARAMETERS:  sleep_state         - Which sleep state we just exited
 569  *
 570  * RETURN:      Status
 571  *
 572  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 573  *              Called with interrupts ENABLED.
 574  *
 575  ******************************************************************************/
 576 acpi_status acpi_leave_sleep_state(u8 sleep_state)
 577 {
 578         struct acpi_object_list arg_list;
 579         union acpi_object arg;
 580         acpi_status status;
 581
 582         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state);
 583
 584         /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
 585
 586         acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 587
 588         /* Setup parameter object */
 589
 590         arg_list.count = 1;
 591         arg_list.pointer = &arg;
 592         arg.type = ACPI_TYPE_INTEGER;
 593
 594         /* Ignore any errors from these methods */
 595
 596         arg.integer.value = ACPI_SST_WAKING;
 597         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 598         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 599                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 600         }
 601
 602         /*
 603          * GPEs must be enabled before _WAK is called as GPEs
 604          * might get fired there
 605          *
 606          * Restore the GPEs:
 607          * 1) Disable/Clear all GPEs
 608          * 2) Enable all runtime GPEs
 609          */
 610         status = acpi_hw_disable_all_gpes();
 611         if (ACPI_FAILURE(status)) {
 612                 return_ACPI_STATUS(status);
 613         }
 614         status = acpi_hw_enable_all_runtime_gpes();
 615         if (ACPI_FAILURE(status)) {
 616                 return_ACPI_STATUS(status);
 617         }
 618
 619         status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
 620         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 621                 ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
 622         }
 623         /* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 624
 625         acpi_gbl_system_awake_and_running = TRUE;
 626
 627         /* Enable power button */
 628
 629         (void)
 630             acpi_set_register(acpi_gbl_fixed_event_info
 631                               [ACPI_EVENT_POWER_BUTTON].enable_register_id, 1);
 632
 633         (void)
 634             acpi_set_register(acpi_gbl_fixed_event_info
 635                               [ACPI_EVENT_POWER_BUTTON].status_register_id, 1);
 636
 637         arg.integer.value = ACPI_SST_WORKING;
 638         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 639         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 640                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 641         }
 642
 643         return_ACPI_STATUS(status);
 644 }
 645
 646 ACPI_EXPORT_SYMBOL(acpi_leave_sleep_state)