git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/acpica/hwsleep.c

   1
   2 /******************************************************************************
   3  *
   4  * Name: hwsleep.c - ACPI Hardware Sleep/Wake Interface
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2008, Intel Corp.
  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 "accommon.h"
  47 #include "actables.h"
  48
  49 #define _COMPONENT          ACPI_HARDWARE
  50 ACPI_MODULE_NAME("hwsleep")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_set_firmware_waking_vector
  55  *
  56  * PARAMETERS:  physical_address    - 32-bit physical address of ACPI real mode
  57  *                                    entry point.
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Sets the 32-bit firmware_waking_vector field of the FACS
  62  *
  63  ******************************************************************************/
  64 acpi_status
  65 acpi_set_firmware_waking_vector(u32 physical_address)
  66 {
  67         ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector);
  68
  69
  70         /*
  71          * According to the ACPI specification 2.0c and later, the 64-bit
  72          * waking vector should be cleared and the 32-bit waking vector should
  73          * be used, unless we want the wake-up code to be called by the BIOS in
  74          * Protected Mode.  Some systems (for example HP dv5-1004nr) are known
  75          * to fail to resume if the 64-bit vector is used.
  76          */
  77
  78         /* Set the 32-bit vector */
  79
  80         acpi_gbl_FACS->firmware_waking_vector = physical_address;
  81
  82         /* Clear the 64-bit vector if it exists */
  83
  84         if ((acpi_gbl_FACS->length > 32) && (acpi_gbl_FACS->version >= 1)) {
  85                 acpi_gbl_FACS->xfirmware_waking_vector = 0;
  86         }
  87
  88         return_ACPI_STATUS(AE_OK);
  89 }
  90
  91 ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector)
  92
  93 /*******************************************************************************
  94  *
  95  * FUNCTION:    acpi_set_firmware_waking_vector64
  96  *
  97  * PARAMETERS:  physical_address    - 64-bit physical address of ACPI protected
  98  *                                    mode entry point.
  99  *
 100  * RETURN:      Status
 101  *
 102  * DESCRIPTION: Sets the 64-bit X_firmware_waking_vector field of the FACS, if
 103  *              it exists in the table.
 104  *
 105  ******************************************************************************/
 106 acpi_status
 107 acpi_set_firmware_waking_vector64(u64 physical_address)
 108 {
 109         ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector64);
 110
 111
 112         /* Determine if the 64-bit vector actually exists */
 113
 114         if ((acpi_gbl_FACS->length <= 32) || (acpi_gbl_FACS->version < 1)) {
 115                 return_ACPI_STATUS(AE_NOT_EXIST);
 116         }
 117
 118         /* Clear 32-bit vector, set the 64-bit X_ vector */
 119
 120         acpi_gbl_FACS->firmware_waking_vector = 0;
 121         acpi_gbl_FACS->xfirmware_waking_vector = physical_address;
 122
 123         return_ACPI_STATUS(AE_OK);
 124 }
 125
 126 ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector64)
 127
 128 /*******************************************************************************
 129  *
 130  * FUNCTION:    acpi_enter_sleep_state_prep
 131  *
 132  * PARAMETERS:  sleep_state         - Which sleep state to enter
 133  *
 134  * RETURN:      Status
 135  *
 136  * DESCRIPTION: Prepare to enter a system sleep state (see ACPI 2.0 spec p 231)
 137  *              This function must execute with interrupts enabled.
 138  *              We break sleeping into 2 stages so that OSPM can handle
 139  *              various OS-specific tasks between the two steps.
 140  *
 141  ******************************************************************************/
 142 acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)
 143 {
 144         acpi_status status;
 145         struct acpi_object_list arg_list;
 146         union acpi_object arg;
 147
 148         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_prep);
 149
 150         /*
 151          * _PSW methods could be run here to enable wake-on keyboard, LAN, etc.
 152          */
 153         status = acpi_get_sleep_type_data(sleep_state,
 154                                           &acpi_gbl_sleep_type_a,
 155                                           &acpi_gbl_sleep_type_b);
 156         if (ACPI_FAILURE(status)) {
 157                 return_ACPI_STATUS(status);
 158         }
 159
 160         /* Setup parameter object */
 161
 162         arg_list.count = 1;
 163         arg_list.pointer = &arg;
 164
 165         arg.type = ACPI_TYPE_INTEGER;
 166         arg.integer.value = sleep_state;
 167
 168         /* Run the _PTS method */
 169
 170         status = acpi_evaluate_object(NULL, METHOD_NAME__PTS, &arg_list, NULL);
 171         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 172                 return_ACPI_STATUS(status);
 173         }
 174
 175         /* Setup the argument to _SST */
 176
 177         switch (sleep_state) {
 178         case ACPI_STATE_S0:
 179                 arg.integer.value = ACPI_SST_WORKING;
 180                 break;
 181
 182         case ACPI_STATE_S1:
 183         case ACPI_STATE_S2:
 184         case ACPI_STATE_S3:
 185                 arg.integer.value = ACPI_SST_SLEEPING;
 186                 break;
 187
 188         case ACPI_STATE_S4:
 189                 arg.integer.value = ACPI_SST_SLEEP_CONTEXT;
 190                 break;
 191
 192         default:
 193                 arg.integer.value = ACPI_SST_INDICATOR_OFF;     /* Default is off */
 194                 break;
 195         }
 196
 197         /*
 198          * Set the system indicators to show the desired sleep state.
 199          * _SST is an optional method (return no error if not found)
 200          */
 201         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 202         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 203                 ACPI_EXCEPTION((AE_INFO, status,
 204                                 "While executing method _SST"));
 205         }
 206
 207         return_ACPI_STATUS(AE_OK);
 208 }
 209
 210 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
 211
 212 /*******************************************************************************
 213  *
 214  * FUNCTION:    acpi_enter_sleep_state
 215  *
 216  * PARAMETERS:  sleep_state         - Which sleep state to enter
 217  *
 218  * RETURN:      Status
 219  *
 220  * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
 221  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 222  *
 223  ******************************************************************************/
 224 acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 225 {
 226         u32 PM1Acontrol;
 227         u32 PM1Bcontrol;
 228         struct acpi_bit_register_info *sleep_type_reg_info;
 229         struct acpi_bit_register_info *sleep_enable_reg_info;
 230         u32 in_value;
 231         struct acpi_object_list arg_list;
 232         union acpi_object arg;
 233         acpi_status status;
 234
 235         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state);
 236
 237         if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
 238             (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
 239                 ACPI_ERROR((AE_INFO, "Sleep values out of range: A=%X B=%X",
 240                             acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
 241                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 242         }
 243
 244         sleep_type_reg_info =
 245             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 246         sleep_enable_reg_info =
 247             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 248
 249         /* Clear wake status */
 250
 251         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 252         if (ACPI_FAILURE(status)) {
 253                 return_ACPI_STATUS(status);
 254         }
 255
 256         /* Clear all fixed and general purpose status bits */
 257
 258         status = acpi_hw_clear_acpi_status();
 259         if (ACPI_FAILURE(status)) {
 260                 return_ACPI_STATUS(status);
 261         }
 262
 263         /*
 264          * 1) Disable/Clear all GPEs
 265          * 2) Enable all wakeup GPEs
 266          */
 267         status = acpi_hw_disable_all_gpes();
 268         if (ACPI_FAILURE(status)) {
 269                 return_ACPI_STATUS(status);
 270         }
 271         acpi_gbl_system_awake_and_running = FALSE;
 272
 273         status = acpi_hw_enable_all_wakeup_gpes();
 274         if (ACPI_FAILURE(status)) {
 275                 return_ACPI_STATUS(status);
 276         }
 277
 278         /* Execute the _GTS method */
 279
 280         arg_list.count = 1;
 281         arg_list.pointer = &arg;
 282         arg.type = ACPI_TYPE_INTEGER;
 283         arg.integer.value = sleep_state;
 284
 285         status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
 286         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 287                 return_ACPI_STATUS(status);
 288         }
 289
 290         /* Get current value of PM1A control */
 291
 292         status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol);
 293         if (ACPI_FAILURE(status)) {
 294                 return_ACPI_STATUS(status);
 295         }
 296         ACPI_DEBUG_PRINT((ACPI_DB_INIT,
 297                           "Entering sleep state [S%d]\n", sleep_state));
 298
 299         /* Clear SLP_EN and SLP_TYP fields */
 300
 301         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 302                          sleep_enable_reg_info->access_bit_mask);
 303         PM1Bcontrol = PM1Acontrol;
 304
 305         /* Insert SLP_TYP bits */
 306
 307         PM1Acontrol |=
 308             (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 309         PM1Bcontrol |=
 310             (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
 311
 312         /*
 313          * We split the writes of SLP_TYP and SLP_EN to workaround
 314          * poorly implemented hardware.
 315          */
 316
 317         /* Write #1: fill in SLP_TYP data */
 318
 319         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 320                                         PM1Acontrol);
 321         if (ACPI_FAILURE(status)) {
 322                 return_ACPI_STATUS(status);
 323         }
 324
 325         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 326                                         PM1Bcontrol);
 327         if (ACPI_FAILURE(status)) {
 328                 return_ACPI_STATUS(status);
 329         }
 330
 331         /* Insert SLP_ENABLE bit */
 332
 333         PM1Acontrol |= sleep_enable_reg_info->access_bit_mask;
 334         PM1Bcontrol |= sleep_enable_reg_info->access_bit_mask;
 335
 336         /* Write #2: SLP_TYP + SLP_EN */
 337
 338         ACPI_FLUSH_CPU_CACHE();
 339
 340         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 341                                         PM1Acontrol);
 342         if (ACPI_FAILURE(status)) {
 343                 return_ACPI_STATUS(status);
 344         }
 345
 346         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 347                                         PM1Bcontrol);
 348         if (ACPI_FAILURE(status)) {
 349                 return_ACPI_STATUS(status);
 350         }
 351
 352         if (sleep_state > ACPI_STATE_S3) {
 353                 /*
 354                  * We wanted to sleep > S3, but it didn't happen (by virtue of the
 355                  * fact that we are still executing!)
 356                  *
 357                  * Wait ten seconds, then try again. This is to get S4/S5 to work on
 358                  * all machines.
 359                  *
 360                  * We wait so long to allow chipsets that poll this reg very slowly to
 361                  * still read the right value. Ideally, this block would go
 362                  * away entirely.
 363                  */
 364                 acpi_os_stall(10000000);
 365
 366                 status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
 367                                                 sleep_enable_reg_info->
 368                                                 access_bit_mask);
 369                 if (ACPI_FAILURE(status)) {
 370                         return_ACPI_STATUS(status);
 371                 }
 372         }
 373
 374         /* Wait until we enter sleep state */
 375
 376         do {
 377                 status = acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS,
 378                                                     &in_value);
 379                 if (ACPI_FAILURE(status)) {
 380                         return_ACPI_STATUS(status);
 381                 }
 382
 383                 /* Spin until we wake */
 384
 385         } while (!in_value);
 386
 387         return_ACPI_STATUS(AE_OK);
 388 }
 389
 390 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state)
 391
 392 /*******************************************************************************
 393  *
 394  * FUNCTION:    acpi_enter_sleep_state_s4bios
 395  *
 396  * PARAMETERS:  None
 397  *
 398  * RETURN:      Status
 399  *
 400  * DESCRIPTION: Perform a S4 bios request.
 401  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 402  *
 403  ******************************************************************************/
 404 acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void)
 405 {
 406         u32 in_value;
 407         acpi_status status;
 408
 409         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_s4bios);
 410
 411         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 412         if (ACPI_FAILURE(status)) {
 413                 return_ACPI_STATUS(status);
 414         }
 415
 416         status = acpi_hw_clear_acpi_status();
 417         if (ACPI_FAILURE(status)) {
 418                 return_ACPI_STATUS(status);
 419         }
 420
 421         /*
 422          * 1) Disable/Clear all GPEs
 423          * 2) Enable all wakeup GPEs
 424          */
 425         status = acpi_hw_disable_all_gpes();
 426         if (ACPI_FAILURE(status)) {
 427                 return_ACPI_STATUS(status);
 428         }
 429         acpi_gbl_system_awake_and_running = FALSE;
 430
 431         status = acpi_hw_enable_all_wakeup_gpes();
 432         if (ACPI_FAILURE(status)) {
 433                 return_ACPI_STATUS(status);
 434         }
 435
 436         ACPI_FLUSH_CPU_CACHE();
 437
 438         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 439                                     (u32) acpi_gbl_FADT.S4bios_request, 8);
 440
 441         do {
 442                 acpi_os_stall(1000);
 443                 status = acpi_get_register(ACPI_BITREG_WAKE_STATUS, &in_value);
 444                 if (ACPI_FAILURE(status)) {
 445                         return_ACPI_STATUS(status);
 446                 }
 447         } while (!in_value);
 448
 449         return_ACPI_STATUS(AE_OK);
 450 }
 451
 452 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_s4bios)
 453
 454 /*******************************************************************************
 455  *
 456  * FUNCTION:    acpi_leave_sleep_state_prep
 457  *
 458  * PARAMETERS:  sleep_state         - Which sleep state we are exiting
 459  *
 460  * RETURN:      Status
 461  *
 462  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
 463  *              sleep.
 464  *              Called with interrupts DISABLED.
 465  *
 466  ******************************************************************************/
 467 acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
 468 {
 469         struct acpi_object_list arg_list;
 470         union acpi_object arg;
 471         acpi_status status;
 472         struct acpi_bit_register_info *sleep_type_reg_info;
 473         struct acpi_bit_register_info *sleep_enable_reg_info;
 474         u32 PM1Acontrol;
 475         u32 PM1Bcontrol;
 476
 477         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state_prep);
 478
 479         /*
 480          * Set SLP_TYPE and SLP_EN to state S0.
 481          * This is unclear from the ACPI Spec, but it is required
 482          * by some machines.
 483          */
 484         status = acpi_get_sleep_type_data(ACPI_STATE_S0,
 485                                           &acpi_gbl_sleep_type_a,
 486                                           &acpi_gbl_sleep_type_b);
 487         if (ACPI_SUCCESS(status)) {
 488                 sleep_type_reg_info =
 489                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 490                 sleep_enable_reg_info =
 491                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 492
 493                 /* Get current value of PM1A control */
 494
 495                 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 496                                                &PM1Acontrol);
 497                 if (ACPI_SUCCESS(status)) {
 498
 499                         /* Clear SLP_EN and SLP_TYP fields */
 500
 501                         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 502                                          sleep_enable_reg_info->
 503                                          access_bit_mask);
 504                         PM1Bcontrol = PM1Acontrol;
 505
 506                         /* Insert SLP_TYP bits */
 507
 508                         PM1Acontrol |=
 509                             (acpi_gbl_sleep_type_a << sleep_type_reg_info->
 510                              bit_position);
 511                         PM1Bcontrol |=
 512                             (acpi_gbl_sleep_type_b << sleep_type_reg_info->
 513                              bit_position);
 514
 515                         /* Just ignore any errors */
 516
 517                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 518                                                      PM1Acontrol);
 519                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 520                                                      PM1Bcontrol);
 521                 }
 522         }
 523
 524         /* Execute the _BFS method */
 525
 526         arg_list.count = 1;
 527         arg_list.pointer = &arg;
 528         arg.type = ACPI_TYPE_INTEGER;
 529         arg.integer.value = sleep_state;
 530
 531         status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
 532         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 533                 ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
 534         }
 535
 536         return_ACPI_STATUS(status);
 537 }
 538
 539 /*******************************************************************************
 540  *
 541  * FUNCTION:    acpi_leave_sleep_state
 542  *
 543  * PARAMETERS:  sleep_state         - Which sleep state we just exited
 544  *
 545  * RETURN:      Status
 546  *
 547  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 548  *              Called with interrupts ENABLED.
 549  *
 550  ******************************************************************************/
 551 acpi_status acpi_leave_sleep_state(u8 sleep_state)
 552 {
 553         struct acpi_object_list arg_list;
 554         union acpi_object arg;
 555         acpi_status status;
 556
 557         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state);
 558
 559         /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
 560
 561         acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 562
 563         /* Setup parameter object */
 564
 565         arg_list.count = 1;
 566         arg_list.pointer = &arg;
 567         arg.type = ACPI_TYPE_INTEGER;
 568
 569         /* Ignore any errors from these methods */
 570
 571         arg.integer.value = ACPI_SST_WAKING;
 572         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 573         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 574                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 575         }
 576
 577         /*
 578          * GPEs must be enabled before _WAK is called as GPEs
 579          * might get fired there
 580          *
 581          * Restore the GPEs:
 582          * 1) Disable/Clear all GPEs
 583          * 2) Enable all runtime GPEs
 584          */
 585         status = acpi_hw_disable_all_gpes();
 586         if (ACPI_FAILURE(status)) {
 587                 return_ACPI_STATUS(status);
 588         }
 589         status = acpi_hw_enable_all_runtime_gpes();
 590         if (ACPI_FAILURE(status)) {
 591                 return_ACPI_STATUS(status);
 592         }
 593
 594         arg.integer.value = sleep_state;
 595         status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
 596         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 597                 ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
 598         }
 599         /* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 600
 601         /*
 602          * Some BIOSes assume that WAK_STS will be cleared on resume and use
 603          * it to determine whether the system is rebooting or resuming. Clear
 604          * it for compatibility.
 605          */
 606         acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 607
 608         acpi_gbl_system_awake_and_running = TRUE;
 609
 610         /* Enable power button */
 611
 612         (void)
 613             acpi_set_register(acpi_gbl_fixed_event_info
 614                               [ACPI_EVENT_POWER_BUTTON].enable_register_id, 1);
 615
 616         (void)
 617             acpi_set_register(acpi_gbl_fixed_event_info
 618                               [ACPI_EVENT_POWER_BUTTON].status_register_id, 1);
 619
 620         arg.integer.value = ACPI_SST_WORKING;
 621         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 622         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 623                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 624         }
 625
 626         return_ACPI_STATUS(status);
 627 }
 628
 629 ACPI_EXPORT_SYMBOL(acpi_leave_sleep_state)