git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/events/evgpe.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evgpe - General Purpose Event handling and dispatch
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2007, R. Byron Moore
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include <acpi/acevents.h>
  46 #include <acpi/acnamesp.h>
  47
  48 #define _COMPONENT          ACPI_EVENTS
  49 ACPI_MODULE_NAME("evgpe")
  50
  51 /* Local prototypes */
  52 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_ev_set_gpe_type
  57  *
  58  * PARAMETERS:  gpe_event_info          - GPE to set
  59  *              Type                    - New type
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Sets the new type for the GPE (wake, run, or wake/run)
  64  *
  65  ******************************************************************************/
  66
  67 acpi_status
  68 acpi_ev_set_gpe_type(struct acpi_gpe_event_info *gpe_event_info, u8 type)
  69 {
  70         acpi_status status;
  71
  72         ACPI_FUNCTION_TRACE(ev_set_gpe_type);
  73
  74         /* Validate type and update register enable masks */
  75
  76         switch (type) {
  77         case ACPI_GPE_TYPE_WAKE:
  78         case ACPI_GPE_TYPE_RUNTIME:
  79         case ACPI_GPE_TYPE_WAKE_RUN:
  80                 break;
  81
  82         default:
  83                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  84         }
  85
  86         /* Disable the GPE if currently enabled */
  87
  88         status = acpi_ev_disable_gpe(gpe_event_info);
  89
  90         /* Type was validated above */
  91
  92         gpe_event_info->flags &= ~ACPI_GPE_TYPE_MASK;   /* Clear type bits */
  93         gpe_event_info->flags |= type;  /* Insert type */
  94         return_ACPI_STATUS(status);
  95 }
  96
  97 /*******************************************************************************
  98  *
  99  * FUNCTION:    acpi_ev_update_gpe_enable_masks
 100  *
 101  * PARAMETERS:  gpe_event_info          - GPE to update
 102  *              Type                    - What to do: ACPI_GPE_DISABLE or
 103  *                                        ACPI_GPE_ENABLE
 104  *
 105  * RETURN:      Status
 106  *
 107  * DESCRIPTION: Updates GPE register enable masks based on the GPE type
 108  *
 109  ******************************************************************************/
 110
 111 acpi_status
 112 acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info,
 113                                 u8 type)
 114 {
 115         struct acpi_gpe_register_info *gpe_register_info;
 116         u8 register_bit;
 117
 118         ACPI_FUNCTION_TRACE(ev_update_gpe_enable_masks);
 119
 120         gpe_register_info = gpe_event_info->register_info;
 121         if (!gpe_register_info) {
 122                 return_ACPI_STATUS(AE_NOT_EXIST);
 123         }
 124         register_bit = (u8)
 125             (1 <<
 126              (gpe_event_info->gpe_number - gpe_register_info->base_gpe_number));
 127
 128         /* 1) Disable case.  Simply clear all enable bits */
 129
 130         if (type == ACPI_GPE_DISABLE) {
 131                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
 132                                register_bit);
 133                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 134                 return_ACPI_STATUS(AE_OK);
 135         }
 136
 137         /* 2) Enable case.  Set/Clear the appropriate enable bits */
 138
 139         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 140         case ACPI_GPE_TYPE_WAKE:
 141                 ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
 142                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
 143                 break;
 144
 145         case ACPI_GPE_TYPE_RUNTIME:
 146                 ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
 147                                register_bit);
 148                 ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
 149                 break;
 150
 151         case ACPI_GPE_TYPE_WAKE_RUN:
 152                 ACPI_SET_BIT(gpe_register_info->enable_for_wake, register_bit);
 153                 ACPI_SET_BIT(gpe_register_info->enable_for_run, register_bit);
 154                 break;
 155
 156         default:
 157                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 158         }
 159
 160         return_ACPI_STATUS(AE_OK);
 161 }
 162
 163 /*******************************************************************************
 164  *
 165  * FUNCTION:    acpi_ev_enable_gpe
 166  *
 167  * PARAMETERS:  gpe_event_info          - GPE to enable
 168  *              write_to_hardware       - Enable now, or just mark data structs
 169  *                                        (WAKE GPEs should be deferred)
 170  *
 171  * RETURN:      Status
 172  *
 173  * DESCRIPTION: Enable a GPE based on the GPE type
 174  *
 175  ******************************************************************************/
 176
 177 acpi_status
 178 acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info,
 179                    u8 write_to_hardware)
 180 {
 181         acpi_status status;
 182
 183         ACPI_FUNCTION_TRACE(ev_enable_gpe);
 184
 185         /* Make sure HW enable masks are updated */
 186
 187         status =
 188             acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_ENABLE);
 189         if (ACPI_FAILURE(status)) {
 190                 return_ACPI_STATUS(status);
 191         }
 192
 193         /* Mark wake-enabled or HW enable, or both */
 194
 195         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 196         case ACPI_GPE_TYPE_WAKE:
 197
 198                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 199                 break;
 200
 201         case ACPI_GPE_TYPE_WAKE_RUN:
 202
 203                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 204
 205                 /*lint -fallthrough */
 206
 207         case ACPI_GPE_TYPE_RUNTIME:
 208
 209                 ACPI_SET_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
 210
 211                 if (write_to_hardware) {
 212
 213                         /* Clear the GPE (of stale events), then enable it */
 214
 215                         status = acpi_hw_clear_gpe(gpe_event_info);
 216                         if (ACPI_FAILURE(status)) {
 217                                 return_ACPI_STATUS(status);
 218                         }
 219
 220                         /* Enable the requested runtime GPE */
 221
 222                         status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
 223                 }
 224                 break;
 225
 226         default:
 227                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 228         }
 229
 230         return_ACPI_STATUS(AE_OK);
 231 }
 232
 233 /*******************************************************************************
 234  *
 235  * FUNCTION:    acpi_ev_disable_gpe
 236  *
 237  * PARAMETERS:  gpe_event_info          - GPE to disable
 238  *
 239  * RETURN:      Status
 240  *
 241  * DESCRIPTION: Disable a GPE based on the GPE type
 242  *
 243  ******************************************************************************/
 244
 245 acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 246 {
 247         acpi_status status;
 248
 249         ACPI_FUNCTION_TRACE(ev_disable_gpe);
 250
 251         if (!(gpe_event_info->flags & ACPI_GPE_ENABLE_MASK)) {
 252                 return_ACPI_STATUS(AE_OK);
 253         }
 254
 255         /* Make sure HW enable masks are updated */
 256
 257         status =
 258             acpi_ev_update_gpe_enable_masks(gpe_event_info, ACPI_GPE_DISABLE);
 259         if (ACPI_FAILURE(status)) {
 260                 return_ACPI_STATUS(status);
 261         }
 262
 263         /* Mark wake-disabled or HW disable, or both */
 264
 265         switch (gpe_event_info->flags & ACPI_GPE_TYPE_MASK) {
 266         case ACPI_GPE_TYPE_WAKE:
 267                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 268                 break;
 269
 270         case ACPI_GPE_TYPE_WAKE_RUN:
 271                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_WAKE_ENABLED);
 272
 273                 /*lint -fallthrough */
 274
 275         case ACPI_GPE_TYPE_RUNTIME:
 276
 277                 /* Disable the requested runtime GPE */
 278
 279                 ACPI_CLEAR_BIT(gpe_event_info->flags, ACPI_GPE_RUN_ENABLED);
 280                 status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
 281                 break;
 282
 283         default:
 284                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 285         }
 286
 287         return_ACPI_STATUS(AE_OK);
 288 }
 289
 290 /*******************************************************************************
 291  *
 292  * FUNCTION:    acpi_ev_get_gpe_event_info
 293  *
 294  * PARAMETERS:  gpe_device          - Device node.  NULL for GPE0/GPE1
 295  *              gpe_number          - Raw GPE number
 296  *
 297  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 298  *
 299  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 300  *              Validates the gpe_block and the gpe_number
 301  *
 302  *              Should be called only when the GPE lists are semaphore locked
 303  *              and not subject to change.
 304  *
 305  ******************************************************************************/
 306
 307 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 308                                                        u32 gpe_number)
 309 {
 310         union acpi_operand_object *obj_desc;
 311         struct acpi_gpe_block_info *gpe_block;
 312         acpi_native_uint i;
 313
 314         ACPI_FUNCTION_ENTRY();
 315
 316         /* A NULL gpe_block means use the FADT-defined GPE block(s) */
 317
 318         if (!gpe_device) {
 319
 320                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 321
 322                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 323                         gpe_block = acpi_gbl_gpe_fadt_blocks[i];
 324                         if (gpe_block) {
 325                                 if ((gpe_number >= gpe_block->block_base_number)
 326                                     && (gpe_number <
 327                                         gpe_block->block_base_number +
 328                                         (gpe_block->register_count * 8))) {
 329                                         return (&gpe_block->
 330                                                 event_info[gpe_number -
 331                                                            gpe_block->
 332                                                            block_base_number]);
 333                                 }
 334                         }
 335                 }
 336
 337                 /* The gpe_number was not in the range of either FADT GPE block */
 338
 339                 return (NULL);
 340         }
 341
 342         /* A Non-NULL gpe_device means this is a GPE Block Device */
 343
 344         obj_desc = acpi_ns_get_attached_object((struct acpi_namespace_node *)
 345                                                gpe_device);
 346         if (!obj_desc || !obj_desc->device.gpe_block) {
 347                 return (NULL);
 348         }
 349
 350         gpe_block = obj_desc->device.gpe_block;
 351
 352         if ((gpe_number >= gpe_block->block_base_number) &&
 353             (gpe_number <
 354              gpe_block->block_base_number + (gpe_block->register_count * 8))) {
 355                 return (&gpe_block->
 356                         event_info[gpe_number - gpe_block->block_base_number]);
 357         }
 358
 359         return (NULL);
 360 }
 361
 362 /*******************************************************************************
 363  *
 364  * FUNCTION:    acpi_ev_gpe_detect
 365  *
 366  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 367  *                                    Can have multiple GPE blocks attached.
 368  *
 369  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 370  *
 371  * DESCRIPTION: Detect if any GP events have occurred.  This function is
 372  *              executed at interrupt level.
 373  *
 374  ******************************************************************************/
 375
 376 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
 377 {
 378         acpi_status status;
 379         struct acpi_gpe_block_info *gpe_block;
 380         struct acpi_gpe_register_info *gpe_register_info;
 381         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 382         u8 enabled_status_byte;
 383         u32 status_reg;
 384         u32 enable_reg;
 385         acpi_cpu_flags flags;
 386         acpi_native_uint i;
 387         acpi_native_uint j;
 388
 389         ACPI_FUNCTION_NAME(ev_gpe_detect);
 390
 391         /* Check for the case where there are no GPEs */
 392
 393         if (!gpe_xrupt_list) {
 394                 return (int_status);
 395         }
 396
 397         /*
 398          * We need to obtain the GPE lock for both the data structs and registers
 399          * Note: Not necessary to obtain the hardware lock, since the GPE registers
 400          * are owned by the gpe_lock.
 401          */
 402         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 403
 404         /* Examine all GPE blocks attached to this interrupt level */
 405
 406         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 407         while (gpe_block) {
 408                 /*
 409                  * Read all of the 8-bit GPE status and enable registers
 410                  * in this GPE block, saving all of them.
 411                  * Find all currently active GP events.
 412                  */
 413                 for (i = 0; i < gpe_block->register_count; i++) {
 414
 415                         /* Get the next status/enable pair */
 416
 417                         gpe_register_info = &gpe_block->register_info[i];
 418
 419                         /* Read the Status Register */
 420
 421                         status =
 422                             acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
 423                                                    &status_reg,
 424                                                    &gpe_register_info->
 425                                                    status_address);
 426                         if (ACPI_FAILURE(status)) {
 427                                 goto unlock_and_exit;
 428                         }
 429
 430                         /* Read the Enable Register */
 431
 432                         status =
 433                             acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
 434                                                    &enable_reg,
 435                                                    &gpe_register_info->
 436                                                    enable_address);
 437                         if (ACPI_FAILURE(status)) {
 438                                 goto unlock_and_exit;
 439                         }
 440
 441                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 442                                           "Read GPE Register at GPE%X: Status=%02X, Enable=%02X\n",
 443                                           gpe_register_info->base_gpe_number,
 444                                           status_reg, enable_reg));
 445
 446                         /* Check if there is anything active at all in this register */
 447
 448                         enabled_status_byte = (u8) (status_reg & enable_reg);
 449                         if (!enabled_status_byte) {
 450
 451                                 /* No active GPEs in this register, move on */
 452
 453                                 continue;
 454                         }
 455
 456                         /* Now look at the individual GPEs in this byte register */
 457
 458                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 459
 460                                 /* Examine one GPE bit */
 461
 462                                 if (enabled_status_byte & (1 << j)) {
 463                                         /*
 464                                          * Found an active GPE. Dispatch the event to a handler
 465                                          * or method.
 466                                          */
 467                                         int_status |=
 468                                             acpi_ev_gpe_dispatch(&gpe_block->
 469                                                                  event_info[(i *
 470                                                                              ACPI_GPE_REGISTER_WIDTH)
 471                                                                             +
 472                                                                             j],
 473                                                                  (u32) j +
 474                                                                  gpe_register_info->
 475                                                                  base_gpe_number);
 476                                 }
 477                         }
 478                 }
 479
 480                 gpe_block = gpe_block->next;
 481         }
 482
 483       unlock_and_exit:
 484
 485         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 486         return (int_status);
 487 }
 488
 489 /*******************************************************************************
 490  *
 491  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 492  *
 493  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 494  *
 495  * RETURN:      None
 496  *
 497  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 498  *              function is called from an invocation of acpi_os_execute and
 499  *              therefore does NOT execute at interrupt level - so that
 500  *              the control method itself is not executed in the context of
 501  *              an interrupt handler.
 502  *
 503  ******************************************************************************/
 504
 505 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 506 {
 507         struct acpi_gpe_event_info *gpe_event_info = (void *)context;
 508         acpi_status status;
 509         struct acpi_gpe_event_info local_gpe_event_info;
 510         struct acpi_evaluate_info *info;
 511
 512         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 513
 514         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 515         if (ACPI_FAILURE(status)) {
 516                 return_VOID;
 517         }
 518
 519         /* Must revalidate the gpe_number/gpe_block */
 520
 521         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
 522                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 523                 return_VOID;
 524         }
 525
 526         /* Set the GPE flags for return to enabled state */
 527
 528         (void)acpi_ev_enable_gpe(gpe_event_info, FALSE);
 529
 530         /*
 531          * Take a snapshot of the GPE info for this level - we copy the
 532          * info to prevent a race condition with remove_handler/remove_block.
 533          */
 534         ACPI_MEMCPY(&local_gpe_event_info, gpe_event_info,
 535                     sizeof(struct acpi_gpe_event_info));
 536
 537         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 538         if (ACPI_FAILURE(status)) {
 539                 return_VOID;
 540         }
 541
 542         /*
 543          * Must check for control method type dispatch one more
 544          * time to avoid race with ev_gpe_install_handler
 545          */
 546         if ((local_gpe_event_info.flags & ACPI_GPE_DISPATCH_MASK) ==
 547             ACPI_GPE_DISPATCH_METHOD) {
 548
 549                 /* Allocate the evaluation information block */
 550
 551                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 552                 if (!info) {
 553                         status = AE_NO_MEMORY;
 554                 } else {
 555                         /*
 556                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
 557                          * control method that corresponds to this GPE
 558                          */
 559                         info->prefix_node =
 560                             local_gpe_event_info.dispatch.method_node;
 561                         info->parameters =
 562                             ACPI_CAST_PTR(union acpi_operand_object *,
 563                                           gpe_event_info);
 564                         info->parameter_type = ACPI_PARAM_GPE;
 565                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 566
 567                         status = acpi_ns_evaluate(info);
 568                         ACPI_FREE(info);
 569                 }
 570
 571                 if (ACPI_FAILURE(status)) {
 572                         ACPI_EXCEPTION((AE_INFO, status,
 573                                         "while evaluating GPE method [%4.4s]",
 574                                         acpi_ut_get_node_name
 575                                         (local_gpe_event_info.dispatch.
 576                                          method_node)));
 577                 }
 578         }
 579
 580         if ((local_gpe_event_info.flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 581             ACPI_GPE_LEVEL_TRIGGERED) {
 582                 /*
 583                  * GPE is level-triggered, we clear the GPE status bit after
 584                  * handling the event.
 585                  */
 586                 status = acpi_hw_clear_gpe(&local_gpe_event_info);
 587                 if (ACPI_FAILURE(status)) {
 588                         return_VOID;
 589                 }
 590         }
 591
 592         /* Enable this GPE */
 593
 594         (void)acpi_hw_write_gpe_enable_reg(&local_gpe_event_info);
 595         return_VOID;
 596 }
 597
 598 /*******************************************************************************
 599  *
 600  * FUNCTION:    acpi_ev_gpe_dispatch
 601  *
 602  * PARAMETERS:  gpe_event_info  - Info for this GPE
 603  *              gpe_number      - Number relative to the parent GPE block
 604  *
 605  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 606  *
 607  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 608  *              or method (e.g. _Lxx/_Exx) handler.
 609  *
 610  *              This function executes at interrupt level.
 611  *
 612  ******************************************************************************/
 613
 614 u32
 615 acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 616 {
 617         acpi_status status;
 618
 619         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 620
 621         acpi_gpe_count++;
 622
 623         /*
 624          * If edge-triggered, clear the GPE status bit now.  Note that
 625          * level-triggered events are cleared after the GPE is serviced.
 626          */
 627         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 628             ACPI_GPE_EDGE_TRIGGERED) {
 629                 status = acpi_hw_clear_gpe(gpe_event_info);
 630                 if (ACPI_FAILURE(status)) {
 631                         ACPI_EXCEPTION((AE_INFO, status,
 632                                         "Unable to clear GPE[%2X]",
 633                                         gpe_number));
 634                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 635                 }
 636         }
 637
 638         /*
 639          * Dispatch the GPE to either an installed handler, or the control method
 640          * associated with this GPE (_Lxx or _Exx). If a handler exists, we invoke
 641          * it and do not attempt to run the method. If there is neither a handler
 642          * nor a method, we disable this GPE to prevent further such pointless
 643          * events from firing.
 644          */
 645         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 646         case ACPI_GPE_DISPATCH_HANDLER:
 647
 648                 /*
 649                  * Invoke the installed handler (at interrupt level)
 650                  * Ignore return status for now.  TBD: leave GPE disabled on error?
 651                  */
 652                 (void)gpe_event_info->dispatch.handler->address(gpe_event_info->
 653                                                                 dispatch.
 654                                                                 handler->
 655                                                                 context);
 656
 657                 /* It is now safe to clear level-triggered events. */
 658
 659                 if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 660                     ACPI_GPE_LEVEL_TRIGGERED) {
 661                         status = acpi_hw_clear_gpe(gpe_event_info);
 662                         if (ACPI_FAILURE(status)) {
 663                                 ACPI_EXCEPTION((AE_INFO, status,
 664                                                 "Unable to clear GPE[%2X]",
 665                                                 gpe_number));
 666                                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 667                         }
 668                 }
 669                 break;
 670
 671         case ACPI_GPE_DISPATCH_METHOD:
 672
 673                 /*
 674                  * Disable the GPE, so it doesn't keep firing before the method has a
 675                  * chance to run (it runs asynchronously with interrupts enabled).
 676                  */
 677                 status = acpi_ev_disable_gpe(gpe_event_info);
 678                 if (ACPI_FAILURE(status)) {
 679                         ACPI_EXCEPTION((AE_INFO, status,
 680                                         "Unable to disable GPE[%2X]",
 681                                         gpe_number));
 682                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 683                 }
 684
 685                 /*
 686                  * Execute the method associated with the GPE
 687                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 688                  */
 689                 status = acpi_os_execute(OSL_GPE_HANDLER,
 690                                          acpi_ev_asynch_execute_gpe_method,
 691                                          gpe_event_info);
 692                 if (ACPI_FAILURE(status)) {
 693                         ACPI_EXCEPTION((AE_INFO, status,
 694                                         "Unable to queue handler for GPE[%2X] - event disabled",
 695                                         gpe_number));
 696                 }
 697                 break;
 698
 699         default:
 700
 701                 /* No handler or method to run! */
 702
 703                 ACPI_ERROR((AE_INFO,
 704                             "No handler or method for GPE[%2X], disabling event",
 705                             gpe_number));
 706
 707                 /*
 708                  * Disable the GPE. The GPE will remain disabled until the ACPI
 709                  * Core Subsystem is restarted, or a handler is installed.
 710                  */
 711                 status = acpi_ev_disable_gpe(gpe_event_info);
 712                 if (ACPI_FAILURE(status)) {
 713                         ACPI_EXCEPTION((AE_INFO, status,
 714                                         "Unable to disable GPE[%2X]",
 715                                         gpe_number));
 716                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 717                 }
 718                 break;
 719         }
 720
 721         return_UINT32(ACPI_INTERRUPT_HANDLED);
 722 }