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 - 2004, 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
  47 #define _COMPONENT          ACPI_HARDWARE
  48          ACPI_MODULE_NAME    ("hwsleep")
  49
  50
  51 #define METHOD_NAME__BFS        "\\_BFS"
  52 #define METHOD_NAME__GTS        "\\_GTS"
  53 #define METHOD_NAME__PTS        "\\_PTS"
  54 #define METHOD_NAME__SST        "\\_SI._SST"
  55 #define METHOD_NAME__WAK        "\\_WAK"
  56
  57 #define ACPI_SST_INDICATOR_OFF  0
  58 #define ACPI_SST_WORKING        1
  59 #define ACPI_SST_WAKING         2
  60 #define ACPI_SST_SLEEPING       3
  61 #define ACPI_SST_SLEEP_CONTEXT  4
  62
  63
  64 /******************************************************************************
  65  *
  66  * FUNCTION:    acpi_set_firmware_waking_vector
  67  *
  68  * PARAMETERS:  physical_address    - Physical address of ACPI real mode
  69  *                                    entry point.
  70  *
  71  * RETURN:      Status
  72  *
  73  * DESCRIPTION: access function for d_firmware_waking_vector field in FACS
  74  *
  75  ******************************************************************************/
  76
  77 acpi_status
  78 acpi_set_firmware_waking_vector (
  79         acpi_physical_address physical_address)
  80 {
  81
  82         ACPI_FUNCTION_TRACE ("acpi_set_firmware_waking_vector");
  83
  84
  85         /* Set the vector */
  86
  87         if (acpi_gbl_common_fACS.vector_width == 32) {
  88                 *(ACPI_CAST_PTR (u32, acpi_gbl_common_fACS.firmware_waking_vector))
  89                                 = (u32) physical_address;
  90         }
  91         else {
  92                 *acpi_gbl_common_fACS.firmware_waking_vector
  93                                 = physical_address;
  94         }
  95
  96         return_ACPI_STATUS (AE_OK);
  97 }
  98
  99
 100 /******************************************************************************
 101  *
 102  * FUNCTION:    acpi_get_firmware_waking_vector
 103  *
 104  * PARAMETERS:  *physical_address   - Output buffer where contents of
 105  *                                    the firmware_waking_vector field of
 106  *                                    the FACS will be stored.
 107  *
 108  * RETURN:      Status
 109  *
 110  * DESCRIPTION: Access function for firmware_waking_vector field in FACS
 111  *
 112  ******************************************************************************/
 113
 114 acpi_status
 115 acpi_get_firmware_waking_vector (
 116         acpi_physical_address *physical_address)
 117 {
 118
 119         ACPI_FUNCTION_TRACE ("acpi_get_firmware_waking_vector");
 120
 121
 122         if (!physical_address) {
 123                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 124         }
 125
 126         /* Get the vector */
 127
 128         if (acpi_gbl_common_fACS.vector_width == 32) {
 129                 *physical_address = (acpi_physical_address)
 130                         *(ACPI_CAST_PTR (u32, acpi_gbl_common_fACS.firmware_waking_vector));
 131         }
 132         else {
 133                 *physical_address =
 134                         *acpi_gbl_common_fACS.firmware_waking_vector;
 135         }
 136
 137         return_ACPI_STATUS (AE_OK);
 138 }
 139
 140
 141 /******************************************************************************
 142  *
 143  * FUNCTION:    acpi_enter_sleep_state_prep
 144  *
 145  * PARAMETERS:  sleep_state         - Which sleep state to enter
 146  *
 147  * RETURN:      Status
 148  *
 149  * DESCRIPTION: Prepare to enter a system sleep state (see ACPI 2.0 spec p 231)
 150  *              This function must execute with interrupts enabled.
 151  *              We break sleeping into 2 stages so that OSPM can handle
 152  *              various OS-specific tasks between the two steps.
 153  *
 154  ******************************************************************************/
 155
 156 acpi_status
 157 acpi_enter_sleep_state_prep (
 158         u8                          sleep_state)
 159 {
 160         acpi_status                 status;
 161         struct acpi_object_list     arg_list;
 162         union acpi_object           arg;
 163
 164
 165         ACPI_FUNCTION_TRACE ("acpi_enter_sleep_state_prep");
 166
 167
 168         /*
 169          * _PSW methods could be run here to enable wake-on keyboard, LAN, etc.
 170          */
 171         status = acpi_get_sleep_type_data (sleep_state,
 172                           &acpi_gbl_sleep_type_a, &acpi_gbl_sleep_type_b);
 173         if (ACPI_FAILURE (status)) {
 174                 return_ACPI_STATUS (status);
 175         }
 176
 177         /* Setup parameter object */
 178
 179         arg_list.count = 1;
 180         arg_list.pointer = &arg;
 181
 182         arg.type = ACPI_TYPE_INTEGER;
 183         arg.integer.value = sleep_state;
 184
 185         /* Run the _PTS and _GTS methods */
 186
 187         status = acpi_evaluate_object (NULL, METHOD_NAME__PTS, &arg_list, NULL);
 188         if (ACPI_FAILURE (status) && status != AE_NOT_FOUND) {
 189                 return_ACPI_STATUS (status);
 190         }
 191
 192         status = acpi_evaluate_object (NULL, METHOD_NAME__GTS, &arg_list, NULL);
 193         if (ACPI_FAILURE (status) && status != AE_NOT_FOUND) {
 194                 return_ACPI_STATUS (status);
 195         }
 196
 197         /* Setup the argument to _SST */
 198
 199         switch (sleep_state) {
 200         case ACPI_STATE_S0:
 201                 arg.integer.value = ACPI_SST_WORKING;
 202                 break;
 203
 204         case ACPI_STATE_S1:
 205         case ACPI_STATE_S2:
 206         case ACPI_STATE_S3:
 207                 arg.integer.value = ACPI_SST_SLEEPING;
 208                 break;
 209
 210         case ACPI_STATE_S4:
 211                 arg.integer.value = ACPI_SST_SLEEP_CONTEXT;
 212                 break;
 213
 214         default:
 215                 arg.integer.value = ACPI_SST_INDICATOR_OFF; /* Default is indicator off */
 216                 break;
 217         }
 218
 219         /* Set the system indicators to show the desired sleep state. */
 220
 221         status = acpi_evaluate_object (NULL, METHOD_NAME__SST, &arg_list, NULL);
 222         if (ACPI_FAILURE (status) && status != AE_NOT_FOUND) {
 223                  ACPI_REPORT_ERROR (("Method _SST failed, %s\n", acpi_format_exception (status)));
 224         }
 225
 226         return_ACPI_STATUS (AE_OK);
 227 }
 228
 229
 230 /******************************************************************************
 231  *
 232  * FUNCTION:    acpi_enter_sleep_state
 233  *
 234  * PARAMETERS:  sleep_state         - Which sleep state to enter
 235  *
 236  * RETURN:      Status
 237  *
 238  * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
 239  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 240  *
 241  ******************************************************************************/
 242
 243 acpi_status asmlinkage
 244 acpi_enter_sleep_state (
 245         u8                              sleep_state)
 246 {
 247         u32                             PM1Acontrol;
 248         u32                             PM1Bcontrol;
 249         struct acpi_bit_register_info   *sleep_type_reg_info;
 250         struct acpi_bit_register_info   *sleep_enable_reg_info;
 251         u32                             in_value;
 252         acpi_status                     status;
 253
 254
 255         ACPI_FUNCTION_TRACE ("acpi_enter_sleep_state");
 256
 257
 258         if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
 259                 (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
 260                 ACPI_REPORT_ERROR (("Sleep values out of range: A=%X B=%X\n",
 261                         acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
 262                 return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
 263         }
 264
 265         sleep_type_reg_info = acpi_hw_get_bit_register_info (ACPI_BITREG_SLEEP_TYPE_A);
 266         sleep_enable_reg_info = acpi_hw_get_bit_register_info (ACPI_BITREG_SLEEP_ENABLE);
 267
 268         /* Clear wake status */
 269
 270         status = acpi_set_register (ACPI_BITREG_WAKE_STATUS, 1, ACPI_MTX_DO_NOT_LOCK);
 271         if (ACPI_FAILURE (status)) {
 272                 return_ACPI_STATUS (status);
 273         }
 274
 275         /* Clear all fixed and general purpose status bits */
 276
 277         status = acpi_hw_clear_acpi_status (ACPI_MTX_DO_NOT_LOCK);
 278         if (ACPI_FAILURE (status)) {
 279                 return_ACPI_STATUS (status);
 280         }
 281
 282         if (sleep_state != ACPI_STATE_S5) {
 283                 /* Disable BM arbitration */
 284
 285                 status = acpi_set_register (ACPI_BITREG_ARB_DISABLE, 1, ACPI_MTX_DO_NOT_LOCK);
 286                 if (ACPI_FAILURE (status)) {
 287                         return_ACPI_STATUS (status);
 288                 }
 289         }
 290
 291         /*
 292          * 1) Disable/Clear all GPEs
 293          * 2) Enable all wakeup GPEs
 294          */
 295         status = acpi_hw_disable_all_gpes (ACPI_ISR);
 296         if (ACPI_FAILURE (status)) {
 297                 return_ACPI_STATUS (status);
 298         }
 299         acpi_gbl_system_awake_and_running = FALSE;
 300
 301         status = acpi_hw_enable_all_wakeup_gpes (ACPI_ISR);
 302         if (ACPI_FAILURE (status)) {
 303                 return_ACPI_STATUS (status);
 304         }
 305
 306         /* Get current value of PM1A control */
 307
 308         status = acpi_hw_register_read (ACPI_MTX_DO_NOT_LOCK, ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol);
 309         if (ACPI_FAILURE (status)) {
 310                 return_ACPI_STATUS (status);
 311         }
 312         ACPI_DEBUG_PRINT ((ACPI_DB_INIT, "Entering sleep state [S%d]\n", sleep_state));
 313
 314         /* Clear SLP_EN and SLP_TYP fields */
 315
 316         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask | sleep_enable_reg_info->access_bit_mask);
 317         PM1Bcontrol = PM1Acontrol;
 318
 319         /* Insert SLP_TYP bits */
 320
 321         PM1Acontrol |= (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 322         PM1Bcontrol |= (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: fill in SLP_TYP data */
 330
 331         status = acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK, ACPI_REGISTER_PM1A_CONTROL, PM1Acontrol);
 332         if (ACPI_FAILURE (status)) {
 333                 return_ACPI_STATUS (status);
 334         }
 335
 336         status = acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK, ACPI_REGISTER_PM1B_CONTROL, PM1Bcontrol);
 337         if (ACPI_FAILURE (status)) {
 338                 return_ACPI_STATUS (status);
 339         }
 340
 341         /* Insert SLP_ENABLE bit */
 342
 343         PM1Acontrol |= sleep_enable_reg_info->access_bit_mask;
 344         PM1Bcontrol |= sleep_enable_reg_info->access_bit_mask;
 345
 346         /* Write #2: SLP_TYP + SLP_EN */
 347
 348         ACPI_FLUSH_CPU_CACHE ();
 349
 350         status = acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK, ACPI_REGISTER_PM1A_CONTROL, PM1Acontrol);
 351         if (ACPI_FAILURE (status)) {
 352                 return_ACPI_STATUS (status);
 353         }
 354
 355         status = acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK, ACPI_REGISTER_PM1B_CONTROL, PM1Bcontrol);
 356         if (ACPI_FAILURE (status)) {
 357                 return_ACPI_STATUS (status);
 358         }
 359
 360         if (sleep_state > ACPI_STATE_S3) {
 361                 /*
 362                  * We wanted to sleep > S3, but it didn't happen (by virtue of the fact that
 363                  * we are still executing!)
 364                  *
 365                  * Wait ten seconds, then try again. This is to get S4/S5 to work on all machines.
 366                  *
 367                  * We wait so long to allow chipsets that poll this reg very slowly to
 368                  * still read the right value. Ideally, this block would go
 369                  * away entirely.
 370                  */
 371                 acpi_os_stall (10000000);
 372
 373                 status = acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK, ACPI_REGISTER_PM1_CONTROL,
 374                                  sleep_enable_reg_info->access_bit_mask);
 375                 if (ACPI_FAILURE (status)) {
 376                         return_ACPI_STATUS (status);
 377                 }
 378         }
 379
 380         /* Wait until we enter sleep state */
 381
 382         do {
 383                 status = acpi_get_register (ACPI_BITREG_WAKE_STATUS, &in_value, ACPI_MTX_DO_NOT_LOCK);
 384                 if (ACPI_FAILURE (status)) {
 385                         return_ACPI_STATUS (status);
 386                 }
 387
 388                 /* Spin until we wake */
 389
 390         } while (!in_value);
 391
 392         return_ACPI_STATUS (AE_OK);
 393 }
 394
 395
 396 /******************************************************************************
 397  *
 398  * FUNCTION:    acpi_enter_sleep_state_s4bios
 399  *
 400  * PARAMETERS:  None
 401  *
 402  * RETURN:      Status
 403  *
 404  * DESCRIPTION: Perform a S4 bios request.
 405  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 406  *
 407  ******************************************************************************/
 408
 409 acpi_status asmlinkage
 410 acpi_enter_sleep_state_s4bios (
 411         void)
 412 {
 413         u32                             in_value;
 414         acpi_status                     status;
 415
 416
 417         ACPI_FUNCTION_TRACE ("acpi_enter_sleep_state_s4bios");
 418
 419
 420         status = acpi_set_register (ACPI_BITREG_WAKE_STATUS, 1, ACPI_MTX_DO_NOT_LOCK);
 421         if (ACPI_FAILURE (status)) {
 422                 return_ACPI_STATUS (status);
 423         }
 424
 425         status = acpi_hw_clear_acpi_status (ACPI_MTX_DO_NOT_LOCK);
 426         if (ACPI_FAILURE (status)) {
 427                 return_ACPI_STATUS (status);
 428         }
 429
 430         /*
 431          * 1) Disable/Clear all GPEs
 432          * 2) Enable all wakeup GPEs
 433          */
 434         status = acpi_hw_disable_all_gpes (ACPI_ISR);
 435         if (ACPI_FAILURE (status)) {
 436                 return_ACPI_STATUS (status);
 437         }
 438         acpi_gbl_system_awake_and_running = FALSE;
 439
 440         status = acpi_hw_enable_all_wakeup_gpes (ACPI_ISR);
 441         if (ACPI_FAILURE (status)) {
 442                 return_ACPI_STATUS (status);
 443         }
 444
 445         ACPI_FLUSH_CPU_CACHE ();
 446
 447         status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd, (u32) acpi_gbl_FADT->S4bios_req, 8);
 448
 449         do {
 450                 acpi_os_stall(1000);
 451                 status = acpi_get_register (ACPI_BITREG_WAKE_STATUS, &in_value, ACPI_MTX_DO_NOT_LOCK);
 452                 if (ACPI_FAILURE (status)) {
 453                         return_ACPI_STATUS (status);
 454                 }
 455         } while (!in_value);
 456
 457         return_ACPI_STATUS (AE_OK);
 458 }
 459
 460
 461 /******************************************************************************
 462  *
 463  * FUNCTION:    acpi_leave_sleep_state
 464  *
 465  * PARAMETERS:  sleep_state         - Which sleep state we just exited
 466  *
 467  * RETURN:      Status
 468  *
 469  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 470  *              Called with interrupts ENABLED.
 471  *
 472  ******************************************************************************/
 473
 474 acpi_status
 475 acpi_leave_sleep_state (
 476         u8                              sleep_state)
 477 {
 478         struct acpi_object_list         arg_list;
 479         union acpi_object               arg;
 480         acpi_status                     status;
 481         struct acpi_bit_register_info   *sleep_type_reg_info;
 482         struct acpi_bit_register_info   *sleep_enable_reg_info;
 483         u32                             PM1Acontrol;
 484         u32                             PM1Bcontrol;
 485
 486
 487         ACPI_FUNCTION_TRACE ("acpi_leave_sleep_state");
 488
 489
 490         /*
 491          * Set SLP_TYPE and SLP_EN to state S0.
 492          * This is unclear from the ACPI Spec, but it is required
 493          * by some machines.
 494          */
 495         status = acpi_get_sleep_type_data (ACPI_STATE_S0,
 496                           &acpi_gbl_sleep_type_a, &acpi_gbl_sleep_type_b);
 497         if (ACPI_SUCCESS (status)) {
 498                 sleep_type_reg_info = acpi_hw_get_bit_register_info (ACPI_BITREG_SLEEP_TYPE_A);
 499                 sleep_enable_reg_info = acpi_hw_get_bit_register_info (ACPI_BITREG_SLEEP_ENABLE);
 500
 501                 /* Get current value of PM1A control */
 502
 503                 status = acpi_hw_register_read (ACPI_MTX_DO_NOT_LOCK,
 504                                  ACPI_REGISTER_PM1_CONTROL, &PM1Acontrol);
 505                 if (ACPI_SUCCESS (status)) {
 506                         /* Clear SLP_EN and SLP_TYP fields */
 507
 508                         PM1Acontrol &= ~(sleep_type_reg_info->access_bit_mask |
 509                                            sleep_enable_reg_info->access_bit_mask);
 510                         PM1Bcontrol = PM1Acontrol;
 511
 512                         /* Insert SLP_TYP bits */
 513
 514                         PM1Acontrol |= (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 515                         PM1Bcontrol |= (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
 516
 517                         /* Just ignore any errors */
 518
 519                         (void) acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK,
 520                                           ACPI_REGISTER_PM1A_CONTROL, PM1Acontrol);
 521                         (void) acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK,
 522                                           ACPI_REGISTER_PM1B_CONTROL, PM1Bcontrol);
 523                 }
 524         }
 525
 526         /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
 527
 528         acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 529
 530         /* Setup parameter object */
 531
 532         arg_list.count = 1;
 533         arg_list.pointer = &arg;
 534         arg.type = ACPI_TYPE_INTEGER;
 535
 536         /* Ignore any errors from these methods */
 537
 538         arg.integer.value = ACPI_SST_WAKING;
 539         status = acpi_evaluate_object (NULL, METHOD_NAME__SST, &arg_list, NULL);
 540         if (ACPI_FAILURE (status) && status != AE_NOT_FOUND) {
 541                 ACPI_REPORT_ERROR (("Method _SST failed, %s\n", acpi_format_exception (status)));
 542         }
 543
 544         arg.integer.value = sleep_state;
 545         status = acpi_evaluate_object (NULL, METHOD_NAME__BFS, &arg_list, NULL);
 546         if (ACPI_FAILURE (status) && status != AE_NOT_FOUND) {
 547                 ACPI_REPORT_ERROR (("Method _BFS failed, %s\n", acpi_format_exception (status)));
 548         }
 549
 550         status = acpi_evaluate_object (NULL, METHOD_NAME__WAK, &arg_list, NULL);
 551         if (ACPI_FAILURE (status) && status != AE_NOT_FOUND) {
 552                 ACPI_REPORT_ERROR (("Method _WAK failed, %s\n", acpi_format_exception (status)));
 553         }
 554         /* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 555
 556         /*
 557          * Restore the GPEs:
 558          * 1) Disable/Clear all GPEs
 559          * 2) Enable all runtime GPEs
 560          */
 561         status = acpi_hw_disable_all_gpes (ACPI_NOT_ISR);
 562         if (ACPI_FAILURE (status)) {
 563                 return_ACPI_STATUS (status);
 564         }
 565         acpi_gbl_system_awake_and_running = TRUE;
 566
 567         status = acpi_hw_enable_all_runtime_gpes (ACPI_NOT_ISR);
 568         if (ACPI_FAILURE (status)) {
 569                 return_ACPI_STATUS (status);
 570         }
 571
 572         /* Enable power button */
 573
 574         (void) acpi_set_register(acpi_gbl_fixed_event_info[ACPI_EVENT_POWER_BUTTON].enable_register_id,
 575                         1, ACPI_MTX_DO_NOT_LOCK);
 576         (void) acpi_set_register(acpi_gbl_fixed_event_info[ACPI_EVENT_POWER_BUTTON].status_register_id,
 577                         1, ACPI_MTX_DO_NOT_LOCK);
 578
 579         /* Enable BM arbitration */
 580
 581         status = acpi_set_register (ACPI_BITREG_ARB_DISABLE, 0, ACPI_MTX_LOCK);
 582         if (ACPI_FAILURE (status)) {
 583                 return_ACPI_STATUS (status);
 584         }
 585
 586         arg.integer.value = ACPI_SST_WORKING;
 587         status = acpi_evaluate_object (NULL, METHOD_NAME__SST, &arg_list, NULL);
 588         if (ACPI_FAILURE (status) && status != AE_NOT_FOUND) {
 589                 ACPI_REPORT_ERROR (("Method _SST failed, %s\n", acpi_format_exception (status)));
 590         }
 591
 592         return_ACPI_STATUS (status);
 593 }