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 - 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 <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 = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
  74                                          ACPI_CAST_INDIRECT_PTR(struct
  75                                                                 acpi_table_header,
  76                                                                 &facs));
  77         if (ACPI_FAILURE(status)) {
  78                 return_ACPI_STATUS(status);
  79         }
  80
  81         /*
  82          * According to the ACPI specification 2.0c and later, the 64-bit
  83          * waking vector should be cleared and the 32-bit waking vector should
  84          * be used, unless we want the wake-up code to be called by the BIOS in
  85          * Protected Mode.  Some systems (for example HP dv5-1004nr) are known
  86          * to fail to resume if the 64-bit vector is used.
  87          */
  88         if (facs->version >= 1)
  89                 facs->xfirmware_waking_vector = 0;
  90
  91         facs->firmware_waking_vector = (u32)physical_address;
  92
  93         return_ACPI_STATUS(AE_OK);
  94 }
  95
  96 ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector)
  97
  98 /*******************************************************************************
  99  *
 100  * FUNCTION:    acpi_get_firmware_waking_vector
 101  *
 102  * PARAMETERS:  *physical_address   - Where the contents of
 103  *                                    the firmware_waking_vector field of
 104  *                                    the FACS will be returned.
 105  *
 106  * RETURN:      Status, vector
 107  *
 108  * DESCRIPTION: Access function for the firmware_waking_vector field in FACS
 109  *
 110  ******************************************************************************/
 111 #ifdef ACPI_FUTURE_USAGE
 112 acpi_status
 113 acpi_get_firmware_waking_vector(acpi_physical_address * physical_address)
 114 {
 115         struct acpi_table_facs *facs;
 116         acpi_status status;
 117
 118         ACPI_FUNCTION_TRACE(acpi_get_firmware_waking_vector);
 119
 120         if (!physical_address) {
 121                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 122         }
 123
 124         /* Get the FACS */
 125
 126         status = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
 127                                          ACPI_CAST_INDIRECT_PTR(struct
 128                                                                 acpi_table_header,
 129                                                                 &facs));
 130         if (ACPI_FAILURE(status)) {
 131                 return_ACPI_STATUS(status);
 132         }
 133
 134         /* Get the vector */
 135         *physical_address = (acpi_physical_address)facs->firmware_waking_vector;
 136
 137         return_ACPI_STATUS(AE_OK);
 138 }
 139
 140 ACPI_EXPORT_SYMBOL(acpi_get_firmware_waking_vector)
 141 #endif
 142 /*******************************************************************************
 143  *
 144  * FUNCTION:    acpi_enter_sleep_state_prep
 145  *
 146  * PARAMETERS:  sleep_state         - Which sleep state to enter
 147  *
 148  * RETURN:      Status
 149  *
 150  * DESCRIPTION: Prepare to enter a system sleep state (see ACPI 2.0 spec p 231)
 151  *              This function must execute with interrupts enabled.
 152  *              We break sleeping into 2 stages so that OSPM can handle
 153  *              various OS-specific tasks between the two steps.
 154  *
 155  ******************************************************************************/
 156 acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)
 157 {
 158         acpi_status status;
 159         struct acpi_object_list arg_list;
 160         union acpi_object arg;
 161
 162         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_prep);
 163
 164         /*
 165          * _PSW methods could be run here to enable wake-on keyboard, LAN, etc.
 166          */
 167         status = acpi_get_sleep_type_data(sleep_state,
 168                                           &acpi_gbl_sleep_type_a,
 169                                           &acpi_gbl_sleep_type_b);
 170         if (ACPI_FAILURE(status)) {
 171                 return_ACPI_STATUS(status);
 172         }
 173
 174         /* Setup parameter object */
 175
 176         arg_list.count = 1;
 177         arg_list.pointer = &arg;
 178
 179         arg.type = ACPI_TYPE_INTEGER;
 180         arg.integer.value = sleep_state;
 181
 182         /* Run the _PTS method */
 183
 184         status = acpi_evaluate_object(NULL, METHOD_NAME__PTS, &arg_list, NULL);
 185         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 186                 return_ACPI_STATUS(status);
 187         }
 188
 189         /* Setup the argument to _SST */
 190
 191         switch (sleep_state) {
 192         case ACPI_STATE_S0:
 193                 arg.integer.value = ACPI_SST_WORKING;
 194                 break;
 195
 196         case ACPI_STATE_S1:
 197         case ACPI_STATE_S2:
 198         case ACPI_STATE_S3:
 199                 arg.integer.value = ACPI_SST_SLEEPING;
 200                 break;
 201
 202         case ACPI_STATE_S4:
 203                 arg.integer.value = ACPI_SST_SLEEP_CONTEXT;
 204                 break;
 205
 206         default:
 207                 arg.integer.value = ACPI_SST_INDICATOR_OFF;     /* Default is off */
 208                 break;
 209         }
 210
 211         /*
 212          * Set the system indicators to show the desired sleep state.
 213          * _SST is an optional method (return no error if not found)
 214          */
 215         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 216         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 217                 ACPI_EXCEPTION((AE_INFO, status,
 218                                 "While executing method _SST"));
 219         }
 220
 221         return_ACPI_STATUS(AE_OK);
 222 }
 223
 224 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
 225
 226 /*******************************************************************************
 227  *
 228  * FUNCTION:    acpi_enter_sleep_state
 229  *
 230  * PARAMETERS:  sleep_state         - Which sleep state to enter
 231  *
 232  * RETURN:      Status
 233  *
 234  * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
 235  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 236  *
 237  ******************************************************************************/
 238 acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 239 {
 240         u32 PM1Acontrol;
 241         u32 PM1Bcontrol;
 242         struct acpi_bit_register_info *sleep_type_reg_info;
 243         struct acpi_bit_register_info *sleep_enable_reg_info;
 244         u32 in_value;
 245         struct acpi_object_list arg_list;
 246         union acpi_object arg;
 247         acpi_status status;
 248
 249         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state);
 250
 251         if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
 252             (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
 253                 ACPI_ERROR((AE_INFO, "Sleep values out of range: A=%X B=%X",
 254                             acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
 255                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 256         }
 257
 258         sleep_type_reg_info =
 259             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 260         sleep_enable_reg_info =
 261             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 262
 263         /* Clear wake status */
 264
 265         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 266         if (ACPI_FAILURE(status)) {
 267                 return_ACPI_STATUS(status);
 268         }
 269
 270         /* Clear all fixed and general purpose status bits */
 271
 272         status = acpi_hw_clear_acpi_status();
 273         if (ACPI_FAILURE(status)) {
 274                 return_ACPI_STATUS(status);
 275         }
 276
 277         /*
 278          * 1) Disable/Clear all GPEs
 279          * 2) Enable all wakeup GPEs
 280          */
 281         status = acpi_hw_disable_all_gpes();
 282         if (ACPI_FAILURE(status)) {
 283                 return_ACPI_STATUS(status);
 284         }
 285         acpi_gbl_system_awake_and_running = FALSE;
 286
 287         status = acpi_hw_enable_all_wakeup_gpes();
 288         if (ACPI_FAILURE(status)) {
 289                 return_ACPI_STATUS(status);
 290         }
 291
 292         /* Execute the _GTS method */
 293
 294         arg_list.count = 1;
 295         arg_list.pointer = &arg;
 296         arg.type = ACPI_TYPE_INTEGER;
 297         arg.integer.value = sleep_state;
 298
 299         status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
 300         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 301                 return_ACPI_STATUS(status);
 302         }
 303
 304         /* Get current value of PM1A control */
 305
 306         status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol);
 307         if (ACPI_FAILURE(status)) {
 308                 return_ACPI_STATUS(status);
 309         }
 310         ACPI_DEBUG_PRINT((ACPI_DB_INIT,
 311                           "Entering sleep state [S%d]\n", sleep_state));
 312
 313         /* Clear SLP_EN and SLP_TYP fields */
 314
 315         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 316                          sleep_enable_reg_info->access_bit_mask);
 317         PM1Bcontrol = PM1Acontrol;
 318
 319         /* Insert SLP_TYP bits */
 320
 321         PM1Acontrol |=
 322             (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 323         PM1Bcontrol |=
 324             (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
 325
 326         /*
 327          * We split the writes of SLP_TYP and SLP_EN to workaround
 328          * poorly implemented hardware.
 329          */
 330
 331         /* Write #1: fill in SLP_TYP data */
 332
 333         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 334                                         PM1Acontrol);
 335         if (ACPI_FAILURE(status)) {
 336                 return_ACPI_STATUS(status);
 337         }
 338
 339         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 340                                         PM1Bcontrol);
 341         if (ACPI_FAILURE(status)) {
 342                 return_ACPI_STATUS(status);
 343         }
 344
 345         /* Insert SLP_ENABLE bit */
 346
 347         PM1Acontrol |= sleep_enable_reg_info->access_bit_mask;
 348         PM1Bcontrol |= sleep_enable_reg_info->access_bit_mask;
 349
 350         /* Write #2: SLP_TYP + SLP_EN */
 351
 352         ACPI_FLUSH_CPU_CACHE();
 353
 354         status = acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 355                                         PM1Acontrol);
 356         if (ACPI_FAILURE(status)) {
 357                 return_ACPI_STATUS(status);
 358         }
 359
 360         status = acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 361                                         PM1Bcontrol);
 362         if (ACPI_FAILURE(status)) {
 363                 return_ACPI_STATUS(status);
 364         }
 365
 366         if (sleep_state > ACPI_STATE_S3) {
 367                 /*
 368                  * We wanted to sleep > S3, but it didn't happen (by virtue of the
 369                  * fact that we are still executing!)
 370                  *
 371                  * Wait ten seconds, then try again. This is to get S4/S5 to work on
 372                  * all machines.
 373                  *
 374                  * We wait so long to allow chipsets that poll this reg very slowly to
 375                  * still read the right value. Ideally, this block would go
 376                  * away entirely.
 377                  */
 378                 acpi_os_stall(10000000);
 379
 380                 status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
 381                                                 sleep_enable_reg_info->
 382                                                 access_bit_mask);
 383                 if (ACPI_FAILURE(status)) {
 384                         return_ACPI_STATUS(status);
 385                 }
 386         }
 387
 388         /* Wait until we enter sleep state */
 389
 390         do {
 391                 status = acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS,
 392                                                     &in_value);
 393                 if (ACPI_FAILURE(status)) {
 394                         return_ACPI_STATUS(status);
 395                 }
 396
 397                 /* Spin until we wake */
 398
 399         } while (!in_value);
 400
 401         return_ACPI_STATUS(AE_OK);
 402 }
 403
 404 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state)
 405
 406 /*******************************************************************************
 407  *
 408  * FUNCTION:    acpi_enter_sleep_state_s4bios
 409  *
 410  * PARAMETERS:  None
 411  *
 412  * RETURN:      Status
 413  *
 414  * DESCRIPTION: Perform a S4 bios request.
 415  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 416  *
 417  ******************************************************************************/
 418 acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void)
 419 {
 420         u32 in_value;
 421         acpi_status status;
 422
 423         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_s4bios);
 424
 425         status = acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 426         if (ACPI_FAILURE(status)) {
 427                 return_ACPI_STATUS(status);
 428         }
 429
 430         status = acpi_hw_clear_acpi_status();
 431         if (ACPI_FAILURE(status)) {
 432                 return_ACPI_STATUS(status);
 433         }
 434
 435         /*
 436          * 1) Disable/Clear all GPEs
 437          * 2) Enable all wakeup GPEs
 438          */
 439         status = acpi_hw_disable_all_gpes();
 440         if (ACPI_FAILURE(status)) {
 441                 return_ACPI_STATUS(status);
 442         }
 443         acpi_gbl_system_awake_and_running = FALSE;
 444
 445         status = acpi_hw_enable_all_wakeup_gpes();
 446         if (ACPI_FAILURE(status)) {
 447                 return_ACPI_STATUS(status);
 448         }
 449
 450         ACPI_FLUSH_CPU_CACHE();
 451
 452         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 453                                     (u32) acpi_gbl_FADT.S4bios_request, 8);
 454
 455         do {
 456                 acpi_os_stall(1000);
 457                 status = acpi_get_register(ACPI_BITREG_WAKE_STATUS, &in_value);
 458                 if (ACPI_FAILURE(status)) {
 459                         return_ACPI_STATUS(status);
 460                 }
 461         } while (!in_value);
 462
 463         return_ACPI_STATUS(AE_OK);
 464 }
 465
 466 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_s4bios)
 467
 468 /*******************************************************************************
 469  *
 470  * FUNCTION:    acpi_leave_sleep_state_prep
 471  *
 472  * PARAMETERS:  sleep_state         - Which sleep state we are exiting
 473  *
 474  * RETURN:      Status
 475  *
 476  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
 477  *              sleep.
 478  *              Called with interrupts DISABLED.
 479  *
 480  ******************************************************************************/
 481 acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
 482 {
 483         struct acpi_object_list arg_list;
 484         union acpi_object arg;
 485         acpi_status status;
 486         struct acpi_bit_register_info *sleep_type_reg_info;
 487         struct acpi_bit_register_info *sleep_enable_reg_info;
 488         u32 PM1Acontrol;
 489         u32 PM1Bcontrol;
 490
 491         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state_prep);
 492
 493         /*
 494          * Set SLP_TYPE and SLP_EN to state S0.
 495          * This is unclear from the ACPI Spec, but it is required
 496          * by some machines.
 497          */
 498         status = acpi_get_sleep_type_data(ACPI_STATE_S0,
 499                                           &acpi_gbl_sleep_type_a,
 500                                           &acpi_gbl_sleep_type_b);
 501         if (ACPI_SUCCESS(status)) {
 502                 sleep_type_reg_info =
 503                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE_A);
 504                 sleep_enable_reg_info =
 505                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 506
 507                 /* Get current value of PM1A control */
 508
 509                 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 510                                                &PM1Acontrol);
 511                 if (ACPI_SUCCESS(status)) {
 512
 513                         /* Clear SLP_EN and SLP_TYP fields */
 514
 515                         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 516                                          sleep_enable_reg_info->
 517                                          access_bit_mask);
 518                         PM1Bcontrol = PM1Acontrol;
 519
 520                         /* Insert SLP_TYP bits */
 521
 522                         PM1Acontrol |=
 523                             (acpi_gbl_sleep_type_a << sleep_type_reg_info->
 524                              bit_position);
 525                         PM1Bcontrol |=
 526                             (acpi_gbl_sleep_type_b << sleep_type_reg_info->
 527                              bit_position);
 528
 529                         /* Just ignore any errors */
 530
 531                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1A_CONTROL,
 532                                                      PM1Acontrol);
 533                         (void)acpi_hw_register_write(ACPI_REGISTER_PM1B_CONTROL,
 534                                                      PM1Bcontrol);
 535                 }
 536         }
 537
 538         /* Execute the _BFS method */
 539
 540         arg_list.count = 1;
 541         arg_list.pointer = &arg;
 542         arg.type = ACPI_TYPE_INTEGER;
 543         arg.integer.value = sleep_state;
 544
 545         status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
 546         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 547                 ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
 548         }
 549
 550         return_ACPI_STATUS(status);
 551 }
 552
 553 /*******************************************************************************
 554  *
 555  * FUNCTION:    acpi_leave_sleep_state
 556  *
 557  * PARAMETERS:  sleep_state         - Which sleep state we just exited
 558  *
 559  * RETURN:      Status
 560  *
 561  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 562  *              Called with interrupts ENABLED.
 563  *
 564  ******************************************************************************/
 565 acpi_status acpi_leave_sleep_state(u8 sleep_state)
 566 {
 567         struct acpi_object_list arg_list;
 568         union acpi_object arg;
 569         acpi_status status;
 570
 571         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state);
 572
 573         /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
 574
 575         acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 576
 577         /* Setup parameter object */
 578
 579         arg_list.count = 1;
 580         arg_list.pointer = &arg;
 581         arg.type = ACPI_TYPE_INTEGER;
 582
 583         /* Ignore any errors from these methods */
 584
 585         arg.integer.value = ACPI_SST_WAKING;
 586         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 587         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 588                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 589         }
 590
 591         /*
 592          * GPEs must be enabled before _WAK is called as GPEs
 593          * might get fired there
 594          *
 595          * Restore the GPEs:
 596          * 1) Disable/Clear all GPEs
 597          * 2) Enable all runtime GPEs
 598          */
 599         status = acpi_hw_disable_all_gpes();
 600         if (ACPI_FAILURE(status)) {
 601                 return_ACPI_STATUS(status);
 602         }
 603         status = acpi_hw_enable_all_runtime_gpes();
 604         if (ACPI_FAILURE(status)) {
 605                 return_ACPI_STATUS(status);
 606         }
 607
 608         arg.integer.value = sleep_state;
 609         status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
 610         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 611                 ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
 612         }
 613         /* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 614
 615         /*
 616          * Some BIOSes assume that WAK_STS will be cleared on resume and use
 617          * it to determine whether the system is rebooting or resuming. Clear
 618          * it for compatibility.
 619          */
 620         acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
 621
 622         acpi_gbl_system_awake_and_running = TRUE;
 623
 624         /* Enable power button */
 625
 626         (void)
 627             acpi_set_register(acpi_gbl_fixed_event_info
 628                               [ACPI_EVENT_POWER_BUTTON].enable_register_id, 1);
 629
 630         (void)
 631             acpi_set_register(acpi_gbl_fixed_event_info
 632                               [ACPI_EVENT_POWER_BUTTON].status_register_id, 1);
 633
 634         arg.integer.value = ACPI_SST_WORKING;
 635         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 636         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 637                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 638         }
 639
 640         return_ACPI_STATUS(status);
 641 }
 642
 643 ACPI_EXPORT_SYMBOL(acpi_leave_sleep_state)