drivers/acpi/acpica/evgpe.c

   1 /******************************************************************************
   2  *
   3  * Module Name: evgpe - General Purpose Event handling and dispatch
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2010, Intel Corp.
   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 "accommon.h"
  46 #include "acevents.h"
  47 #include "acnamesp.h"
  48
  49 #define _COMPONENT          ACPI_EVENTS
  50 ACPI_MODULE_NAME("evgpe")
  51
  52 /* Local prototypes */
  53 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
  54
  55 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context);
  56
  57 /*******************************************************************************
  58  *
  59  * FUNCTION:    acpi_ev_update_gpe_enable_mask
  60  *
  61  * PARAMETERS:  gpe_event_info          - GPE to update
  62  *
  63  * RETURN:      Status
  64  *
  65  * DESCRIPTION: Updates GPE register enable mask based upon whether there are
  66  *              runtime references to this GPE
  67  *
  68  ******************************************************************************/
  69
  70 acpi_status
  71 acpi_ev_update_gpe_enable_mask(struct acpi_gpe_event_info *gpe_event_info)
  72 {
  73         struct acpi_gpe_register_info *gpe_register_info;
  74         u32 register_bit;
  75
  76         ACPI_FUNCTION_TRACE(ev_update_gpe_enable_mask);
  77
  78         gpe_register_info = gpe_event_info->register_info;
  79         if (!gpe_register_info) {
  80                 return_ACPI_STATUS(AE_NOT_EXIST);
  81         }
  82
  83         register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info,
  84                                                 gpe_register_info);
  85
  86         /* Clear the run bit up front */
  87
  88         ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
  89
  90         /* Set the mask bit only if there are references to this GPE */
  91
  92         if (gpe_event_info->runtime_count) {
  93                 ACPI_SET_BIT(gpe_register_info->enable_for_run, (u8)register_bit);
  94         }
  95
  96         return_ACPI_STATUS(AE_OK);
  97 }
  98
  99 /*******************************************************************************
 100  *
 101  * FUNCTION:    acpi_ev_enable_gpe
 102  *
 103  * PARAMETERS:  gpe_event_info  - GPE to enable
 104  *
 105  * RETURN:      Status
 106  *
 107  * DESCRIPTION: Clear the given GPE from stale events and enable it.
 108  *
 109  ******************************************************************************/
 110 acpi_status
 111 acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
 112 {
 113         acpi_status status;
 114
 115         ACPI_FUNCTION_TRACE(ev_enable_gpe);
 116
 117         /*
 118          * We will only allow a GPE to be enabled if it has either an
 119          * associated method (_Lxx/_Exx) or a handler. Otherwise, the
 120          * GPE will be immediately disabled by acpi_ev_gpe_dispatch the
 121          * first time it fires.
 122          */
 123         if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)) {
 124                 return_ACPI_STATUS(AE_NO_HANDLER);
 125         }
 126
 127         /* Clear the GPE (of stale events) */
 128         status = acpi_hw_clear_gpe(gpe_event_info);
 129         if (ACPI_FAILURE(status)) {
 130                 return_ACPI_STATUS(status);
 131         }
 132
 133         /* Enable the requested GPE */
 134         status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
 135
 136         return_ACPI_STATUS(status);
 137 }
 138
 139
 140 /*******************************************************************************
 141  *
 142  * FUNCTION:    acpi_ev_add_gpe_reference
 143  *
 144  * PARAMETERS:  gpe_event_info  - GPE to enable
 145  *
 146  * RETURN:      Status
 147  *
 148  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
 149  *              hardware-enabled.
 150  *
 151  ******************************************************************************/
 152
 153 acpi_status acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 154 {
 155         acpi_status status = AE_OK;
 156
 157         ACPI_FUNCTION_TRACE(ev_add_gpe_reference);
 158
 159         if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
 160                 return_ACPI_STATUS(AE_LIMIT);
 161         }
 162
 163         gpe_event_info->runtime_count++;
 164         if (gpe_event_info->runtime_count == 1) {
 165                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 166                 if (ACPI_SUCCESS(status)) {
 167                         status = acpi_ev_enable_gpe(gpe_event_info);
 168                 }
 169
 170                 if (ACPI_FAILURE(status)) {
 171                         gpe_event_info->runtime_count--;
 172                 }
 173         }
 174
 175         return_ACPI_STATUS(status);
 176 }
 177
 178 /*******************************************************************************
 179  *
 180  * FUNCTION:    acpi_ev_remove_gpe_reference
 181  *
 182  * PARAMETERS:  gpe_event_info  - GPE to disable
 183  *
 184  * RETURN:      Status
 185  *
 186  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
 187  *              removed, the GPE is hardware-disabled.
 188  *
 189  ******************************************************************************/
 190
 191 acpi_status acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info)
 192 {
 193         acpi_status status = AE_OK;
 194
 195         ACPI_FUNCTION_TRACE(ev_remove_gpe_reference);
 196
 197         if (!gpe_event_info->runtime_count) {
 198                 return_ACPI_STATUS(AE_LIMIT);
 199         }
 200
 201         gpe_event_info->runtime_count--;
 202         if (!gpe_event_info->runtime_count) {
 203                 status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
 204                 if (ACPI_SUCCESS(status)) {
 205                         status = acpi_hw_low_set_gpe(gpe_event_info,
 206                                                      ACPI_GPE_DISABLE);
 207                 }
 208
 209                 if (ACPI_FAILURE(status)) {
 210                         gpe_event_info->runtime_count++;
 211                 }
 212         }
 213
 214         return_ACPI_STATUS(status);
 215 }
 216
 217 /*******************************************************************************
 218  *
 219  * FUNCTION:    acpi_ev_low_get_gpe_info
 220  *
 221  * PARAMETERS:  gpe_number          - Raw GPE number
 222  *              gpe_block           - A GPE info block
 223  *
 224  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
 225  *              is not within the specified GPE block)
 226  *
 227  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
 228  *              the low-level implementation of ev_get_gpe_event_info.
 229  *
 230  ******************************************************************************/
 231
 232 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
 233                                                      struct acpi_gpe_block_info
 234                                                      *gpe_block)
 235 {
 236         u32 gpe_index;
 237
 238         /*
 239          * Validate that the gpe_number is within the specified gpe_block.
 240          * (Two steps)
 241          */
 242         if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
 243                 return (NULL);
 244         }
 245
 246         gpe_index = gpe_number - gpe_block->block_base_number;
 247         if (gpe_index >= gpe_block->gpe_count) {
 248                 return (NULL);
 249         }
 250
 251         return (&gpe_block->event_info[gpe_index]);
 252 }
 253
 254
 255 /*******************************************************************************
 256  *
 257  * FUNCTION:    acpi_ev_get_gpe_event_info
 258  *
 259  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
 260  *              gpe_number          - Raw GPE number
 261  *
 262  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
 263  *
 264  * DESCRIPTION: Returns the event_info struct associated with this GPE.
 265  *              Validates the gpe_block and the gpe_number
 266  *
 267  *              Should be called only when the GPE lists are semaphore locked
 268  *              and not subject to change.
 269  *
 270  ******************************************************************************/
 271
 272 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
 273                                                        u32 gpe_number)
 274 {
 275         union acpi_operand_object *obj_desc;
 276         struct acpi_gpe_event_info *gpe_info;
 277         u32 i;
 278
 279         ACPI_FUNCTION_ENTRY();
 280
 281         /* A NULL gpe_device means use the FADT-defined GPE block(s) */
 282
 283         if (!gpe_device) {
 284
 285                 /* Examine GPE Block 0 and 1 (These blocks are permanent) */
 286
 287                 for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
 288                         gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
 289                                                             acpi_gbl_gpe_fadt_blocks
 290                                                             [i]);
 291                         if (gpe_info) {
 292                                 return (gpe_info);
 293                         }
 294                 }
 295
 296                 /* The gpe_number was not in the range of either FADT GPE block */
 297
 298                 return (NULL);
 299         }
 300
 301         /* A Non-NULL gpe_device means this is a GPE Block Device */
 302
 303         obj_desc = acpi_ns_get_attached_object((struct acpi_namespace_node *)
 304                                                gpe_device);
 305         if (!obj_desc || !obj_desc->device.gpe_block) {
 306                 return (NULL);
 307         }
 308
 309         return (acpi_ev_low_get_gpe_info
 310                 (gpe_number, obj_desc->device.gpe_block));
 311 }
 312
 313 /*******************************************************************************
 314  *
 315  * FUNCTION:    acpi_ev_gpe_detect
 316  *
 317  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 318  *                                    Can have multiple GPE blocks attached.
 319  *
 320  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 321  *
 322  * DESCRIPTION: Detect if any GP events have occurred. This function is
 323  *              executed at interrupt level.
 324  *
 325  ******************************************************************************/
 326
 327 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
 328 {
 329         acpi_status status;
 330         struct acpi_gpe_block_info *gpe_block;
 331         struct acpi_gpe_register_info *gpe_register_info;
 332         u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
 333         u8 enabled_status_byte;
 334         u32 status_reg;
 335         u32 enable_reg;
 336         acpi_cpu_flags flags;
 337         u32 i;
 338         u32 j;
 339
 340         ACPI_FUNCTION_NAME(ev_gpe_detect);
 341
 342         /* Check for the case where there are no GPEs */
 343
 344         if (!gpe_xrupt_list) {
 345                 return (int_status);
 346         }
 347
 348         /*
 349          * We need to obtain the GPE lock for both the data structs and registers
 350          * Note: Not necessary to obtain the hardware lock, since the GPE
 351          * registers are owned by the gpe_lock.
 352          */
 353         flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
 354
 355         /* Examine all GPE blocks attached to this interrupt level */
 356
 357         gpe_block = gpe_xrupt_list->gpe_block_list_head;
 358         while (gpe_block) {
 359                 /*
 360                  * Read all of the 8-bit GPE status and enable registers in this GPE
 361                  * block, saving all of them. Find all currently active GP events.
 362                  */
 363                 for (i = 0; i < gpe_block->register_count; i++) {
 364
 365                         /* Get the next status/enable pair */
 366
 367                         gpe_register_info = &gpe_block->register_info[i];
 368
 369                         /* Read the Status Register */
 370
 371                         status =
 372                             acpi_hw_read(&status_reg,
 373                                          &gpe_register_info->status_address);
 374                         if (ACPI_FAILURE(status)) {
 375                                 goto unlock_and_exit;
 376                         }
 377
 378                         /* Read the Enable Register */
 379
 380                         status =
 381                             acpi_hw_read(&enable_reg,
 382                                          &gpe_register_info->enable_address);
 383                         if (ACPI_FAILURE(status)) {
 384                                 goto unlock_and_exit;
 385                         }
 386
 387                         ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
 388                                           "Read GPE Register at GPE%X: Status=%02X, Enable=%02X\n",
 389                                           gpe_register_info->base_gpe_number,
 390                                           status_reg, enable_reg));
 391
 392                         /* Check if there is anything active at all in this register */
 393
 394                         enabled_status_byte = (u8) (status_reg & enable_reg);
 395                         if (!enabled_status_byte) {
 396
 397                                 /* No active GPEs in this register, move on */
 398
 399                                 continue;
 400                         }
 401
 402                         /* Now look at the individual GPEs in this byte register */
 403
 404                         for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
 405
 406                                 /* Examine one GPE bit */
 407
 408                                 if (enabled_status_byte & (1 << j)) {
 409                                         /*
 410                                          * Found an active GPE. Dispatch the event to a handler
 411                                          * or method.
 412                                          */
 413                                         int_status |=
 414                                             acpi_ev_gpe_dispatch(gpe_block->
 415                                                                  node,
 416                                                                  &gpe_block->
 417                                                 event_info[((acpi_size) i * ACPI_GPE_REGISTER_WIDTH) + j], j + gpe_register_info->base_gpe_number);
 418                                 }
 419                         }
 420                 }
 421
 422                 gpe_block = gpe_block->next;
 423         }
 424
 425       unlock_and_exit:
 426
 427         acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
 428         return (int_status);
 429 }
 430
 431 /*******************************************************************************
 432  *
 433  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 434  *
 435  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 436  *
 437  * RETURN:      None
 438  *
 439  * DESCRIPTION: Perform the actual execution of a GPE control method. This
 440  *              function is called from an invocation of acpi_os_execute and
 441  *              therefore does NOT execute at interrupt level - so that
 442  *              the control method itself is not executed in the context of
 443  *              an interrupt handler.
 444  *
 445  ******************************************************************************/
 446
 447 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
 448 {
 449         struct acpi_gpe_event_info *gpe_event_info = context;
 450         acpi_status status;
 451         struct acpi_gpe_event_info *local_gpe_event_info;
 452         struct acpi_evaluate_info *info;
 453
 454         ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
 455
 456         /* Allocate a local GPE block */
 457
 458         local_gpe_event_info =
 459             ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_event_info));
 460         if (!local_gpe_event_info) {
 461                 ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY, "while handling a GPE"));
 462                 return_VOID;
 463         }
 464
 465         status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
 466         if (ACPI_FAILURE(status)) {
 467                 return_VOID;
 468         }
 469
 470         /* Must revalidate the gpe_number/gpe_block */
 471
 472         if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
 473                 status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 474                 return_VOID;
 475         }
 476
 477         /*
 478          * Take a snapshot of the GPE info for this level - we copy the info to
 479          * prevent a race condition with remove_handler/remove_block.
 480          */
 481         ACPI_MEMCPY(local_gpe_event_info, gpe_event_info,
 482                     sizeof(struct acpi_gpe_event_info));
 483
 484         status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
 485         if (ACPI_FAILURE(status)) {
 486                 return_VOID;
 487         }
 488
 489         /*
 490          * Must check for control method type dispatch one more time to avoid a
 491          * race with ev_gpe_install_handler
 492          */
 493         if ((local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
 494             ACPI_GPE_DISPATCH_METHOD) {
 495
 496                 /* Allocate the evaluation information block */
 497
 498                 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 499                 if (!info) {
 500                         status = AE_NO_MEMORY;
 501                 } else {
 502                         /*
 503                          * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
 504                          * control method that corresponds to this GPE
 505                          */
 506                         info->prefix_node =
 507                             local_gpe_event_info->dispatch.method_node;
 508                         info->flags = ACPI_IGNORE_RETURN_VALUE;
 509
 510                         status = acpi_ns_evaluate(info);
 511                         ACPI_FREE(info);
 512                 }
 513
 514                 if (ACPI_FAILURE(status)) {
 515                         ACPI_EXCEPTION((AE_INFO, status,
 516                                         "while evaluating GPE method [%4.4s]",
 517                                         acpi_ut_get_node_name
 518                                         (local_gpe_event_info->dispatch.
 519                                          method_node)));
 520                 }
 521         }
 522
 523         /* Defer enabling of GPE until all notify handlers are done */
 524
 525         status = acpi_os_execute(OSL_NOTIFY_HANDLER,
 526                                  acpi_ev_asynch_enable_gpe,
 527                                  local_gpe_event_info);
 528         if (ACPI_FAILURE(status)) {
 529                 ACPI_FREE(local_gpe_event_info);
 530         }
 531         return_VOID;
 532 }
 533
 534 /*******************************************************************************
 535  *
 536  * FUNCTION:    acpi_ev_asynch_enable_gpe
 537  *
 538  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 539  *              Callback from acpi_os_execute
 540  *
 541  * RETURN:      None
 542  *
 543  * DESCRIPTION: Asynchronous clear/enable for GPE. This allows the GPE to
 544  *              complete.
 545  *
 546  ******************************************************************************/
 547
 548 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
 549 {
 550         struct acpi_gpe_event_info *gpe_event_info = context;
 551         acpi_status status;
 552
 553         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 554             ACPI_GPE_LEVEL_TRIGGERED) {
 555                 /*
 556                  * GPE is level-triggered, we clear the GPE status bit after handling
 557                  * the event.
 558                  */
 559                 status = acpi_hw_clear_gpe(gpe_event_info);
 560                 if (ACPI_FAILURE(status)) {
 561                         goto exit;
 562                 }
 563         }
 564
 565         /*
 566          * Enable this GPE, conditionally. This means that the GPE will only be
 567          * physically enabled if the enable_for_run bit is set in the event_info
 568          */
 569         (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
 570
 571 exit:
 572         ACPI_FREE(gpe_event_info);
 573         return;
 574 }
 575
 576 /*******************************************************************************
 577  *
 578  * FUNCTION:    acpi_ev_gpe_dispatch
 579  *
 580  * PARAMETERS:  gpe_device      - Device node. NULL for GPE0/GPE1
 581  *              gpe_event_info  - Info for this GPE
 582  *              gpe_number      - Number relative to the parent GPE block
 583  *
 584  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 585  *
 586  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 587  *              or method (e.g. _Lxx/_Exx) handler.
 588  *
 589  *              This function executes at interrupt level.
 590  *
 591  ******************************************************************************/
 592
 593 u32
 594 acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
 595                     struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
 596 {
 597         acpi_status status;
 598
 599         ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
 600
 601         acpi_os_gpe_count(gpe_number);
 602
 603         /*
 604          * If edge-triggered, clear the GPE status bit now. Note that
 605          * level-triggered events are cleared after the GPE is serviced.
 606          */
 607         if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 608             ACPI_GPE_EDGE_TRIGGERED) {
 609                 status = acpi_hw_clear_gpe(gpe_event_info);
 610                 if (ACPI_FAILURE(status)) {
 611                         ACPI_EXCEPTION((AE_INFO, status,
 612                                         "Unable to clear GPE[0x%2X]",
 613                                         gpe_number));
 614                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 615                 }
 616         }
 617
 618         /*
 619          * Dispatch the GPE to either an installed handler, or the control method
 620          * associated with this GPE (_Lxx or _Exx). If a handler exists, we invoke
 621          * it and do not attempt to run the method. If there is neither a handler
 622          * nor a method, we disable this GPE to prevent further such pointless
 623          * events from firing.
 624          */
 625         switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
 626         case ACPI_GPE_DISPATCH_HANDLER:
 627
 628                 /*
 629                  * Invoke the installed handler (at interrupt level)
 630                  * Ignore return status for now.
 631                  * TBD: leave GPE disabled on error?
 632                  */
 633                 (void)gpe_event_info->dispatch.handler->address(gpe_device,
 634                                                                 gpe_number,
 635                                                                 gpe_event_info->
 636                                                                 dispatch.
 637                                                                 handler->
 638                                                                 context);
 639
 640                 /* It is now safe to clear level-triggered events. */
 641
 642                 if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
 643                     ACPI_GPE_LEVEL_TRIGGERED) {
 644                         status = acpi_hw_clear_gpe(gpe_event_info);
 645                         if (ACPI_FAILURE(status)) {
 646                                 ACPI_EXCEPTION((AE_INFO, status,
 647                                         "Unable to clear GPE[0x%2X]",
 648                                                 gpe_number));
 649                                 return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 650                         }
 651                 }
 652                 break;
 653
 654         case ACPI_GPE_DISPATCH_METHOD:
 655
 656                 /*
 657                  * Disable the GPE, so it doesn't keep firing before the method has a
 658                  * chance to run (it runs asynchronously with interrupts enabled).
 659                  */
 660                 status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 661                 if (ACPI_FAILURE(status)) {
 662                         ACPI_EXCEPTION((AE_INFO, status,
 663                                         "Unable to disable GPE[0x%2X]",
 664                                         gpe_number));
 665                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 666                 }
 667
 668                 /*
 669                  * Execute the method associated with the GPE
 670                  * NOTE: Level-triggered GPEs are cleared after the method completes.
 671                  */
 672                 status = acpi_os_execute(OSL_GPE_HANDLER,
 673                                          acpi_ev_asynch_execute_gpe_method,
 674                                          gpe_event_info);
 675                 if (ACPI_FAILURE(status)) {
 676                         ACPI_EXCEPTION((AE_INFO, status,
 677                                         "Unable to queue handler for GPE[0x%2X] - event disabled",
 678                                         gpe_number));
 679                 }
 680                 break;
 681
 682         default:
 683
 684                 /*
 685                  * No handler or method to run!
 686                  * 03/2010: This case should no longer be possible. We will not allow
 687                  * a GPE to be enabled if it has no handler or method.
 688                  */
 689                 ACPI_ERROR((AE_INFO,
 690                             "No handler or method for GPE[0x%2X], disabling event",
 691                             gpe_number));
 692
 693                 /*
 694                  * Disable the GPE. The GPE will remain disabled a handler
 695                  * is installed or ACPICA is restarted.
 696                  */
 697                 status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
 698                 if (ACPI_FAILURE(status)) {
 699                         ACPI_EXCEPTION((AE_INFO, status,
 700                                         "Unable to disable GPE[0x%2X]",
 701                                         gpe_number));
 702                         return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
 703                 }
 704                 break;
 705         }
 706
 707         return_UINT32(ACPI_INTERRUPT_HANDLED);
 708 }