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 #if ACPI_MACHINE_WIDTH == 64
  94 /*******************************************************************************
  95  *
  96  * FUNCTION:    acpi_set_firmware_waking_vector64
  97  *
  98  * PARAMETERS:  physical_address    - 64-bit physical address of ACPI protected
  99  *                                    mode entry point.
 100  *
 101  * RETURN:      Status
 102  *
 103  * DESCRIPTION: Sets the 64-bit X_firmware_waking_vector field of the FACS, if
 104  *              it exists in the table. This function is intended for use with
 105  *              64-bit host operating systems.
 106  *
 107  ******************************************************************************/
 108 acpi_status
 109 acpi_set_firmware_waking_vector64(u64 physical_address)
 110 {
 111         ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector64);
 112
 113
 114         /* Determine if the 64-bit vector actually exists */
 115
 116         if ((acpi_gbl_FACS->length <= 32) || (acpi_gbl_FACS->version < 1)) {
 117                 return_ACPI_STATUS(AE_NOT_EXIST);
 118         }
 119
 120         /* Clear 32-bit vector, set the 64-bit X_ vector */
 121
 122         acpi_gbl_FACS->firmware_waking_vector = 0;
 123         acpi_gbl_FACS->xfirmware_waking_vector = physical_address;
 124
 125         return_ACPI_STATUS(AE_OK);
 126 }
 127
 128 ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector64)
 129 #endif
 130
 131 /*******************************************************************************
 132  *
 133  * FUNCTION:    acpi_enter_sleep_state_prep
 134  *
 135  * PARAMETERS:  sleep_state         - Which sleep state to enter
 136  *
 137  * RETURN:      Status
 138  *
 139  * DESCRIPTION: Prepare to enter a system sleep state (see ACPI 2.0 spec p 231)
 140  *              This function must execute with interrupts enabled.
 141  *              We break sleeping into 2 stages so that OSPM can handle
 142  *              various OS-specific tasks between the two steps.
 143  *
 144  ******************************************************************************/
 145 acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)
 146 {
 147         acpi_status status;
 148         struct acpi_object_list arg_list;
 149         union acpi_object arg;
 150
 151         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_prep);
 152
 153         /* _PSW methods could be run here to enable wake-on keyboard, LAN, etc. */
 154
 155         status = acpi_get_sleep_type_data(sleep_state,
 156                                           &acpi_gbl_sleep_type_a,
 157                                           &acpi_gbl_sleep_type_b);
 158         if (ACPI_FAILURE(status)) {
 159                 return_ACPI_STATUS(status);
 160         }
 161
 162         /* Setup parameter object */
 163
 164         arg_list.count = 1;
 165         arg_list.pointer = &arg;
 166
 167         arg.type = ACPI_TYPE_INTEGER;
 168         arg.integer.value = sleep_state;
 169
 170         /* Run the _PTS method */
 171
 172         status = acpi_evaluate_object(NULL, METHOD_NAME__PTS, &arg_list, NULL);
 173         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 174                 return_ACPI_STATUS(status);
 175         }
 176
 177         /* Setup the argument to _SST */
 178
 179         switch (sleep_state) {
 180         case ACPI_STATE_S0:
 181                 arg.integer.value = ACPI_SST_WORKING;
 182                 break;
 183
 184         case ACPI_STATE_S1:
 185         case ACPI_STATE_S2:
 186         case ACPI_STATE_S3:
 187                 arg.integer.value = ACPI_SST_SLEEPING;
 188                 break;
 189
 190         case ACPI_STATE_S4:
 191                 arg.integer.value = ACPI_SST_SLEEP_CONTEXT;
 192                 break;
 193
 194         default:
 195                 arg.integer.value = ACPI_SST_INDICATOR_OFF;     /* Default is off */
 196                 break;
 197         }
 198
 199         /*
 200          * Set the system indicators to show the desired sleep state.
 201          * _SST is an optional method (return no error if not found)
 202          */
 203         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 204         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 205                 ACPI_EXCEPTION((AE_INFO, status,
 206                                 "While executing method _SST"));
 207         }
 208
 209         return_ACPI_STATUS(AE_OK);
 210 }
 211
 212 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
 213
 214 static unsigned int gts, bfs;
 215 module_param(gts, uint, 0644);
 216 module_param(bfs, uint, 0644);
 217 MODULE_PARM_DESC(gts, "Enable evaluation of _GTS on suspend.");
 218 MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);
 219
 220 /*******************************************************************************
 221  *
 222  * FUNCTION:    acpi_enter_sleep_state
 223  *
 224  * PARAMETERS:  sleep_state         - Which sleep state to enter
 225  *
 226  * RETURN:      Status
 227  *
 228  * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
 229  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 230  *
 231  ******************************************************************************/
 232 acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 233 {
 234         u32 pm1a_control;
 235         u32 pm1b_control;
 236         struct acpi_bit_register_info *sleep_type_reg_info;
 237         struct acpi_bit_register_info *sleep_enable_reg_info;
 238         u32 in_value;
 239         struct acpi_object_list arg_list;
 240         union acpi_object arg;
 241         acpi_status status;
 242
 243         ACPI_FUNCTION_TRACE(acpi_enter_sleep_state);
 244
 245         if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
 246             (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
 247                 ACPI_ERROR((AE_INFO, "Sleep values out of range: A=%X B=%X",
 248                             acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
 249                 return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
 250         }
 251
 252         sleep_type_reg_info =
 253             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
 254         sleep_enable_reg_info =
 255             acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 256
 257         /* Clear wake status */
 258
 259         status =
 260             acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, ACPI_CLEAR_STATUS);
 261         if (ACPI_FAILURE(status)) {
 262                 return_ACPI_STATUS(status);
 263         }
 264
 265         /* Clear all fixed and general purpose status bits */
 266
 267         status = acpi_hw_clear_acpi_status();
 268         if (ACPI_FAILURE(status)) {
 269                 return_ACPI_STATUS(status);
 270         }
 271
 272         /*
 273          * 1) Disable/Clear all GPEs
 274          * 2) Enable all wakeup GPEs
 275          */
 276         status = acpi_hw_disable_all_gpes();
 277         if (ACPI_FAILURE(status)) {
 278                 return_ACPI_STATUS(status);
 279         }
 280         acpi_gbl_system_awake_and_running = FALSE;
 281
 282         status = acpi_hw_enable_all_wakeup_gpes();
 283         if (ACPI_FAILURE(status)) {
 284                 return_ACPI_STATUS(status);
 285         }
 286
 287         if (gts) {
 288                 /* Execute the _GTS method */
 289
 290                 arg_list.count = 1;
 291                 arg_list.pointer = &arg;
 292                 arg.type = ACPI_TYPE_INTEGER;
 293                 arg.integer.value = sleep_state;
 294
 295                 status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
 296                 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 297                         return_ACPI_STATUS(status);
 298                 }
 299         }
 300
 301         /* Get current value of PM1A control */
 302
 303         status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 304                                        &pm1a_control);
 305         if (ACPI_FAILURE(status)) {
 306                 return_ACPI_STATUS(status);
 307         }
 308         ACPI_DEBUG_PRINT((ACPI_DB_INIT,
 309                           "Entering sleep state [S%d]\n", sleep_state));
 310
 311         /* Clear the SLP_EN and SLP_TYP fields */
 312
 313         pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
 314                           sleep_enable_reg_info->access_bit_mask);
 315         pm1b_control = pm1a_control;
 316
 317         /* Insert the SLP_TYP bits */
 318
 319         pm1a_control |=
 320             (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 321         pm1b_control |=
 322             (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
 323
 324         /*
 325          * We split the writes of SLP_TYP and SLP_EN to workaround
 326          * poorly implemented hardware.
 327          */
 328
 329         /* Write #1: write the SLP_TYP data to the PM1 Control registers */
 330
 331         status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
 332         if (ACPI_FAILURE(status)) {
 333                 return_ACPI_STATUS(status);
 334         }
 335
 336         /* Insert the sleep enable (SLP_EN) bit */
 337
 338         pm1a_control |= sleep_enable_reg_info->access_bit_mask;
 339         pm1b_control |= sleep_enable_reg_info->access_bit_mask;
 340
 341         /* Flush caches, as per ACPI specification */
 342
 343         ACPI_FLUSH_CPU_CACHE();
 344
 345         /* Write #2: Write both SLP_TYP + SLP_EN */
 346
 347         status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
 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
 361                  * to 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_read_bit_register(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         /* Clear the wake status bit (PM1) */
 412
 413         status =
 414             acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, ACPI_CLEAR_STATUS);
 415         if (ACPI_FAILURE(status)) {
 416                 return_ACPI_STATUS(status);
 417         }
 418
 419         status = acpi_hw_clear_acpi_status();
 420         if (ACPI_FAILURE(status)) {
 421                 return_ACPI_STATUS(status);
 422         }
 423
 424         /*
 425          * 1) Disable/Clear all GPEs
 426          * 2) Enable all wakeup GPEs
 427          */
 428         status = acpi_hw_disable_all_gpes();
 429         if (ACPI_FAILURE(status)) {
 430                 return_ACPI_STATUS(status);
 431         }
 432         acpi_gbl_system_awake_and_running = FALSE;
 433
 434         status = acpi_hw_enable_all_wakeup_gpes();
 435         if (ACPI_FAILURE(status)) {
 436                 return_ACPI_STATUS(status);
 437         }
 438
 439         ACPI_FLUSH_CPU_CACHE();
 440
 441         status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
 442                                     (u32) acpi_gbl_FADT.S4bios_request, 8);
 443
 444         do {
 445                 acpi_os_stall(1000);
 446                 status =
 447                     acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
 448                 if (ACPI_FAILURE(status)) {
 449                         return_ACPI_STATUS(status);
 450                 }
 451         } while (!in_value);
 452
 453         return_ACPI_STATUS(AE_OK);
 454 }
 455
 456 ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_s4bios)
 457
 458 /*******************************************************************************
 459  *
 460  * FUNCTION:    acpi_leave_sleep_state_prep
 461  *
 462  * PARAMETERS:  sleep_state         - Which sleep state we are exiting
 463  *
 464  * RETURN:      Status
 465  *
 466  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
 467  *              sleep.
 468  *              Called with interrupts DISABLED.
 469  *
 470  ******************************************************************************/
 471 acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
 472 {
 473         struct acpi_object_list arg_list;
 474         union acpi_object arg;
 475         acpi_status status;
 476         struct acpi_bit_register_info *sleep_type_reg_info;
 477         struct acpi_bit_register_info *sleep_enable_reg_info;
 478         u32 pm1a_control;
 479         u32 pm1b_control;
 480
 481         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state_prep);
 482
 483         /*
 484          * Set SLP_TYPE and SLP_EN to state S0.
 485          * This is unclear from the ACPI Spec, but it is required
 486          * by some machines.
 487          */
 488         status = acpi_get_sleep_type_data(ACPI_STATE_S0,
 489                                           &acpi_gbl_sleep_type_a,
 490                                           &acpi_gbl_sleep_type_b);
 491         if (ACPI_SUCCESS(status)) {
 492                 sleep_type_reg_info =
 493                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
 494                 sleep_enable_reg_info =
 495                     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
 496
 497                 /* Get current value of PM1A control */
 498
 499                 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 500                                                &pm1a_control);
 501                 if (ACPI_SUCCESS(status)) {
 502
 503                         /* Clear the SLP_EN and SLP_TYP fields */
 504
 505                         pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
 506                                           sleep_enable_reg_info->
 507                                           access_bit_mask);
 508                         pm1b_control = pm1a_control;
 509
 510                         /* Insert the SLP_TYP bits */
 511
 512                         pm1a_control |= (acpi_gbl_sleep_type_a <<
 513                                          sleep_type_reg_info->bit_position);
 514                         pm1b_control |= (acpi_gbl_sleep_type_b <<
 515                                          sleep_type_reg_info->bit_position);
 516
 517                         /* Write the control registers and ignore any errors */
 518
 519                         (void)acpi_hw_write_pm1_control(pm1a_control,
 520                                                         pm1b_control);
 521                 }
 522         }
 523
 524         if (bfs) {
 525                 /* Execute the _BFS method */
 526
 527                 arg_list.count = 1;
 528                 arg_list.pointer = &arg;
 529                 arg.type = ACPI_TYPE_INTEGER;
 530                 arg.integer.value = sleep_state;
 531
 532                 status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
 533                 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 534                         ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
 535                 }
 536         }
 537         return_ACPI_STATUS(status);
 538 }
 539
 540 /*******************************************************************************
 541  *
 542  * FUNCTION:    acpi_leave_sleep_state
 543  *
 544  * PARAMETERS:  sleep_state         - Which sleep state we just exited
 545  *
 546  * RETURN:      Status
 547  *
 548  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 549  *              Called with interrupts ENABLED.
 550  *
 551  ******************************************************************************/
 552 acpi_status acpi_leave_sleep_state(u8 sleep_state)
 553 {
 554         struct acpi_object_list arg_list;
 555         union acpi_object arg;
 556         acpi_status status;
 557
 558         ACPI_FUNCTION_TRACE(acpi_leave_sleep_state);
 559
 560         /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
 561
 562         acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 563
 564         /* Setup parameter object */
 565
 566         arg_list.count = 1;
 567         arg_list.pointer = &arg;
 568         arg.type = ACPI_TYPE_INTEGER;
 569
 570         /* Ignore any errors from these methods */
 571
 572         arg.integer.value = ACPI_SST_WAKING;
 573         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 574         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 575                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 576         }
 577
 578         /*
 579          * GPEs must be enabled before _WAK is called as GPEs
 580          * might get fired there
 581          *
 582          * Restore the GPEs:
 583          * 1) Disable/Clear all GPEs
 584          * 2) Enable all runtime GPEs
 585          */
 586         status = acpi_hw_disable_all_gpes();
 587         if (ACPI_FAILURE(status)) {
 588                 return_ACPI_STATUS(status);
 589         }
 590         status = acpi_hw_enable_all_runtime_gpes();
 591         if (ACPI_FAILURE(status)) {
 592                 return_ACPI_STATUS(status);
 593         }
 594
 595         arg.integer.value = sleep_state;
 596         status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
 597         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 598                 ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
 599         }
 600         /* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 601
 602         /*
 603          * Some BIOSes assume that WAK_STS will be cleared on resume and use
 604          * it to determine whether the system is rebooting or resuming. Clear
 605          * it for compatibility.
 606          */
 607         acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, 1);
 608
 609         acpi_gbl_system_awake_and_running = TRUE;
 610
 611         /* Enable power button */
 612
 613         (void)
 614             acpi_write_bit_register(acpi_gbl_fixed_event_info
 615                               [ACPI_EVENT_POWER_BUTTON].
 616                               enable_register_id, ACPI_ENABLE_EVENT);
 617
 618         (void)
 619             acpi_write_bit_register(acpi_gbl_fixed_event_info
 620                               [ACPI_EVENT_POWER_BUTTON].
 621                               status_register_id, ACPI_CLEAR_STATUS);
 622
 623         arg.integer.value = ACPI_SST_WORKING;
 624         status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
 625         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 626                 ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
 627         }
 628
 629         return_ACPI_STATUS(status);
 630 }
 631
 632 ACPI_EXPORT_SYMBOL(acpi_leave_sleep_state)