drivers/acpi/acpica/dsmethod.c

   1 /******************************************************************************
   2  *
   3  * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2011, 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 "acdispat.h"
  47 #include "acinterp.h"
  48 #include "acnamesp.h"
  49 #ifdef  ACPI_DISASSEMBLER
  50 #include <acpi/acdisasm.h>
  51 #endif
  52
  53 #define _COMPONENT          ACPI_DISPATCHER
  54 ACPI_MODULE_NAME("dsmethod")
  55
  56 /* Local prototypes */
  57 static acpi_status
  58 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
  59
  60 /*******************************************************************************
  61  *
  62  * FUNCTION:    acpi_ds_method_error
  63  *
  64  * PARAMETERS:  Status          - Execution status
  65  *              walk_state      - Current state
  66  *
  67  * RETURN:      Status
  68  *
  69  * DESCRIPTION: Called on method error. Invoke the global exception handler if
  70  *              present, dump the method data if the disassembler is configured
  71  *
  72  *              Note: Allows the exception handler to change the status code
  73  *
  74  ******************************************************************************/
  75
  76 acpi_status
  77 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
  78 {
  79         ACPI_FUNCTION_ENTRY();
  80
  81         /* Ignore AE_OK and control exception codes */
  82
  83         if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
  84                 return (status);
  85         }
  86
  87         /* Invoke the global exception handler */
  88
  89         if (acpi_gbl_exception_handler) {
  90
  91                 /* Exit the interpreter, allow handler to execute methods */
  92
  93                 acpi_ex_exit_interpreter();
  94
  95                 /*
  96                  * Handler can map the exception code to anything it wants, including
  97                  * AE_OK, in which case the executing method will not be aborted.
  98                  */
  99                 status = acpi_gbl_exception_handler(status,
 100                                                     walk_state->method_node ?
 101                                                     walk_state->method_node->
 102                                                     name.integer : 0,
 103                                                     walk_state->opcode,
 104                                                     walk_state->aml_offset,
 105                                                     NULL);
 106                 acpi_ex_enter_interpreter();
 107         }
 108
 109         acpi_ds_clear_implicit_return(walk_state);
 110
 111 #ifdef ACPI_DISASSEMBLER
 112         if (ACPI_FAILURE(status)) {
 113
 114                 /* Display method locals/args if disassembler is present */
 115
 116                 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
 117         }
 118 #endif
 119
 120         return (status);
 121 }
 122
 123 /*******************************************************************************
 124  *
 125  * FUNCTION:    acpi_ds_create_method_mutex
 126  *
 127  * PARAMETERS:  obj_desc            - The method object
 128  *
 129  * RETURN:      Status
 130  *
 131  * DESCRIPTION: Create a mutex object for a serialized control method
 132  *
 133  ******************************************************************************/
 134
 135 static acpi_status
 136 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
 137 {
 138         union acpi_operand_object *mutex_desc;
 139         acpi_status status;
 140
 141         ACPI_FUNCTION_TRACE(ds_create_method_mutex);
 142
 143         /* Create the new mutex object */
 144
 145         mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
 146         if (!mutex_desc) {
 147                 return_ACPI_STATUS(AE_NO_MEMORY);
 148         }
 149
 150         /* Create the actual OS Mutex */
 151
 152         status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
 153         if (ACPI_FAILURE(status)) {
 154                 return_ACPI_STATUS(status);
 155         }
 156
 157         mutex_desc->mutex.sync_level = method_desc->method.sync_level;
 158         method_desc->method.mutex = mutex_desc;
 159         return_ACPI_STATUS(AE_OK);
 160 }
 161
 162 /*******************************************************************************
 163  *
 164  * FUNCTION:    acpi_ds_begin_method_execution
 165  *
 166  * PARAMETERS:  method_node         - Node of the method
 167  *              obj_desc            - The method object
 168  *              walk_state          - current state, NULL if not yet executing
 169  *                                    a method.
 170  *
 171  * RETURN:      Status
 172  *
 173  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
 174  *              increments the thread count, and waits at the method semaphore
 175  *              for clearance to execute.
 176  *
 177  ******************************************************************************/
 178
 179 acpi_status
 180 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
 181                                union acpi_operand_object *obj_desc,
 182                                struct acpi_walk_state *walk_state)
 183 {
 184         acpi_status status = AE_OK;
 185
 186         ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
 187
 188         if (!method_node) {
 189                 return_ACPI_STATUS(AE_NULL_ENTRY);
 190         }
 191
 192         /* Prevent wraparound of thread count */
 193
 194         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
 195                 ACPI_ERROR((AE_INFO,
 196                             "Method reached maximum reentrancy limit (255)"));
 197                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
 198         }
 199
 200         /*
 201          * If this method is serialized, we need to acquire the method mutex.
 202          */
 203         if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
 204                 /*
 205                  * Create a mutex for the method if it is defined to be Serialized
 206                  * and a mutex has not already been created. We defer the mutex creation
 207                  * until a method is actually executed, to minimize the object count
 208                  */
 209                 if (!obj_desc->method.mutex) {
 210                         status = acpi_ds_create_method_mutex(obj_desc);
 211                         if (ACPI_FAILURE(status)) {
 212                                 return_ACPI_STATUS(status);
 213                         }
 214                 }
 215
 216                 /*
 217                  * The current_sync_level (per-thread) must be less than or equal to
 218                  * the sync level of the method. This mechanism provides some
 219                  * deadlock prevention
 220                  *
 221                  * Top-level method invocation has no walk state at this point
 222                  */
 223                 if (walk_state &&
 224                     (walk_state->thread->current_sync_level >
 225                      obj_desc->method.mutex->mutex.sync_level)) {
 226                         ACPI_ERROR((AE_INFO,
 227                                     "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",
 228                                     acpi_ut_get_node_name(method_node),
 229                                     walk_state->thread->current_sync_level));
 230
 231                         return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
 232                 }
 233
 234                 /*
 235                  * Obtain the method mutex if necessary. Do not acquire mutex for a
 236                  * recursive call.
 237                  */
 238                 if (!walk_state ||
 239                     !obj_desc->method.mutex->mutex.thread_id ||
 240                     (walk_state->thread->thread_id !=
 241                      obj_desc->method.mutex->mutex.thread_id)) {
 242                         /*
 243                          * Acquire the method mutex. This releases the interpreter if we
 244                          * block (and reacquires it before it returns)
 245                          */
 246                         status =
 247                             acpi_ex_system_wait_mutex(obj_desc->method.mutex->
 248                                                       mutex.os_mutex,
 249                                                       ACPI_WAIT_FOREVER);
 250                         if (ACPI_FAILURE(status)) {
 251                                 return_ACPI_STATUS(status);
 252                         }
 253
 254                         /* Update the mutex and walk info and save the original sync_level */
 255
 256                         if (walk_state) {
 257                                 obj_desc->method.mutex->mutex.
 258                                     original_sync_level =
 259                                     walk_state->thread->current_sync_level;
 260
 261                                 obj_desc->method.mutex->mutex.thread_id =
 262                                     walk_state->thread->thread_id;
 263                                 walk_state->thread->current_sync_level =
 264                                     obj_desc->method.sync_level;
 265                         } else {
 266                                 obj_desc->method.mutex->mutex.
 267                                     original_sync_level =
 268                                     obj_desc->method.mutex->mutex.sync_level;
 269                         }
 270                 }
 271
 272                 /* Always increase acquisition depth */
 273
 274                 obj_desc->method.mutex->mutex.acquisition_depth++;
 275         }
 276
 277         /*
 278          * Allocate an Owner ID for this method, only if this is the first thread
 279          * to begin concurrent execution. We only need one owner_id, even if the
 280          * method is invoked recursively.
 281          */
 282         if (!obj_desc->method.owner_id) {
 283                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 284                 if (ACPI_FAILURE(status)) {
 285                         goto cleanup;
 286                 }
 287         }
 288
 289         /*
 290          * Increment the method parse tree thread count since it has been
 291          * reentered one more time (even if it is the same thread)
 292          */
 293         obj_desc->method.thread_count++;
 294         return_ACPI_STATUS(status);
 295
 296       cleanup:
 297         /* On error, must release the method mutex (if present) */
 298
 299         if (obj_desc->method.mutex) {
 300                 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
 301         }
 302         return_ACPI_STATUS(status);
 303 }
 304
 305 /*******************************************************************************
 306  *
 307  * FUNCTION:    acpi_ds_call_control_method
 308  *
 309  * PARAMETERS:  Thread              - Info for this thread
 310  *              this_walk_state     - Current walk state
 311  *              Op                  - Current Op to be walked
 312  *
 313  * RETURN:      Status
 314  *
 315  * DESCRIPTION: Transfer execution to a called control method
 316  *
 317  ******************************************************************************/
 318
 319 acpi_status
 320 acpi_ds_call_control_method(struct acpi_thread_state *thread,
 321                             struct acpi_walk_state *this_walk_state,
 322                             union acpi_parse_object *op)
 323 {
 324         acpi_status status;
 325         struct acpi_namespace_node *method_node;
 326         struct acpi_walk_state *next_walk_state = NULL;
 327         union acpi_operand_object *obj_desc;
 328         struct acpi_evaluate_info *info;
 329         u32 i;
 330
 331         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
 332
 333         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 334                           "Calling method %p, currentstate=%p\n",
 335                           this_walk_state->prev_op, this_walk_state));
 336
 337         /*
 338          * Get the namespace entry for the control method we are about to call
 339          */
 340         method_node = this_walk_state->method_call_node;
 341         if (!method_node) {
 342                 return_ACPI_STATUS(AE_NULL_ENTRY);
 343         }
 344
 345         obj_desc = acpi_ns_get_attached_object(method_node);
 346         if (!obj_desc) {
 347                 return_ACPI_STATUS(AE_NULL_OBJECT);
 348         }
 349
 350         /* Init for new method, possibly wait on method mutex */
 351
 352         status = acpi_ds_begin_method_execution(method_node, obj_desc,
 353                                                 this_walk_state);
 354         if (ACPI_FAILURE(status)) {
 355                 return_ACPI_STATUS(status);
 356         }
 357
 358         /* Begin method parse/execution. Create a new walk state */
 359
 360         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
 361                                                     NULL, obj_desc, thread);
 362         if (!next_walk_state) {
 363                 status = AE_NO_MEMORY;
 364                 goto cleanup;
 365         }
 366
 367         /*
 368          * The resolved arguments were put on the previous walk state's operand
 369          * stack. Operands on the previous walk state stack always
 370          * start at index 0. Also, null terminate the list of arguments
 371          */
 372         this_walk_state->operands[this_walk_state->num_operands] = NULL;
 373
 374         /*
 375          * Allocate and initialize the evaluation information block
 376          * TBD: this is somewhat inefficient, should change interface to
 377          * ds_init_aml_walk. For now, keeps this struct off the CPU stack
 378          */
 379         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
 380         if (!info) {
 381                 return_ACPI_STATUS(AE_NO_MEMORY);
 382         }
 383
 384         info->parameters = &this_walk_state->operands[0];
 385
 386         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
 387                                        obj_desc->method.aml_start,
 388                                        obj_desc->method.aml_length, info,
 389                                        ACPI_IMODE_EXECUTE);
 390
 391         ACPI_FREE(info);
 392         if (ACPI_FAILURE(status)) {
 393                 goto cleanup;
 394         }
 395
 396         /*
 397          * Delete the operands on the previous walkstate operand stack
 398          * (they were copied to new objects)
 399          */
 400         for (i = 0; i < obj_desc->method.param_count; i++) {
 401                 acpi_ut_remove_reference(this_walk_state->operands[i]);
 402                 this_walk_state->operands[i] = NULL;
 403         }
 404
 405         /* Clear the operand stack */
 406
 407         this_walk_state->num_operands = 0;
 408
 409         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 410                           "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
 411                           method_node->name.ascii, next_walk_state));
 412
 413         /* Invoke an internal method if necessary */
 414
 415         if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
 416                 status =
 417                     obj_desc->method.dispatch.implementation(next_walk_state);
 418                 if (status == AE_OK) {
 419                         status = AE_CTRL_TERMINATE;
 420                 }
 421         }
 422
 423         return_ACPI_STATUS(status);
 424
 425       cleanup:
 426
 427         /* On error, we must terminate the method properly */
 428
 429         acpi_ds_terminate_control_method(obj_desc, next_walk_state);
 430         if (next_walk_state) {
 431                 acpi_ds_delete_walk_state(next_walk_state);
 432         }
 433
 434         return_ACPI_STATUS(status);
 435 }
 436
 437 /*******************************************************************************
 438  *
 439  * FUNCTION:    acpi_ds_restart_control_method
 440  *
 441  * PARAMETERS:  walk_state          - State for preempted method (caller)
 442  *              return_desc         - Return value from the called method
 443  *
 444  * RETURN:      Status
 445  *
 446  * DESCRIPTION: Restart a method that was preempted by another (nested) method
 447  *              invocation.  Handle the return value (if any) from the callee.
 448  *
 449  ******************************************************************************/
 450
 451 acpi_status
 452 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
 453                                union acpi_operand_object *return_desc)
 454 {
 455         acpi_status status;
 456         int same_as_implicit_return;
 457
 458         ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
 459
 460         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 461                           "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
 462                           acpi_ut_get_node_name(walk_state->method_node),
 463                           walk_state->method_call_op, return_desc));
 464
 465         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 466                           "    ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
 467                           walk_state->return_used,
 468                           walk_state->results, walk_state));
 469
 470         /* Did the called method return a value? */
 471
 472         if (return_desc) {
 473
 474                 /* Is the implicit return object the same as the return desc? */
 475
 476                 same_as_implicit_return =
 477                     (walk_state->implicit_return_obj == return_desc);
 478
 479                 /* Are we actually going to use the return value? */
 480
 481                 if (walk_state->return_used) {
 482
 483                         /* Save the return value from the previous method */
 484
 485                         status = acpi_ds_result_push(return_desc, walk_state);
 486                         if (ACPI_FAILURE(status)) {
 487                                 acpi_ut_remove_reference(return_desc);
 488                                 return_ACPI_STATUS(status);
 489                         }
 490
 491                         /*
 492                          * Save as THIS method's return value in case it is returned
 493                          * immediately to yet another method
 494                          */
 495                         walk_state->return_desc = return_desc;
 496                 }
 497
 498                 /*
 499                  * The following code is the optional support for the so-called
 500                  * "implicit return". Some AML code assumes that the last value of the
 501                  * method is "implicitly" returned to the caller, in the absence of an
 502                  * explicit return value.
 503                  *
 504                  * Just save the last result of the method as the return value.
 505                  *
 506                  * NOTE: this is optional because the ASL language does not actually
 507                  * support this behavior.
 508                  */
 509                 else if (!acpi_ds_do_implicit_return
 510                          (return_desc, walk_state, FALSE)
 511                          || same_as_implicit_return) {
 512                         /*
 513                          * Delete the return value if it will not be used by the
 514                          * calling method or remove one reference if the explicit return
 515                          * is the same as the implicit return value.
 516                          */
 517                         acpi_ut_remove_reference(return_desc);
 518                 }
 519         }
 520
 521         return_ACPI_STATUS(AE_OK);
 522 }
 523
 524 /*******************************************************************************
 525  *
 526  * FUNCTION:    acpi_ds_terminate_control_method
 527  *
 528  * PARAMETERS:  method_desc         - Method object
 529  *              walk_state          - State associated with the method
 530  *
 531  * RETURN:      None
 532  *
 533  * DESCRIPTION: Terminate a control method.  Delete everything that the method
 534  *              created, delete all locals and arguments, and delete the parse
 535  *              tree if requested.
 536  *
 537  * MUTEX:       Interpreter is locked
 538  *
 539  ******************************************************************************/
 540
 541 void
 542 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 543                                  struct acpi_walk_state *walk_state)
 544 {
 545
 546         ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
 547
 548         /* method_desc is required, walk_state is optional */
 549
 550         if (!method_desc) {
 551                 return_VOID;
 552         }
 553
 554         if (walk_state) {
 555
 556                 /* Delete all arguments and locals */
 557
 558                 acpi_ds_method_data_delete_all(walk_state);
 559
 560                 /*
 561                  * If method is serialized, release the mutex and restore the
 562                  * current sync level for this thread
 563                  */
 564                 if (method_desc->method.mutex) {
 565
 566                         /* Acquisition Depth handles recursive calls */
 567
 568                         method_desc->method.mutex->mutex.acquisition_depth--;
 569                         if (!method_desc->method.mutex->mutex.acquisition_depth) {
 570                                 walk_state->thread->current_sync_level =
 571                                     method_desc->method.mutex->mutex.
 572                                     original_sync_level;
 573
 574                                 acpi_os_release_mutex(method_desc->method.
 575                                                       mutex->mutex.os_mutex);
 576                                 method_desc->method.mutex->mutex.thread_id = 0;
 577                         }
 578                 }
 579
 580                 /*
 581                  * Delete any namespace objects created anywhere within the
 582                  * namespace by the execution of this method. Unless:
 583                  * 1) This method is a module-level executable code method, in which
 584                  *    case we want make the objects permanent.
 585                  * 2) There are other threads executing the method, in which case we
 586                  *    will wait until the last thread has completed.
 587                  */
 588                 if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
 589                     && (method_desc->method.thread_count == 1)) {
 590
 591                         /* Delete any direct children of (created by) this method */
 592
 593                         acpi_ns_delete_namespace_subtree(walk_state->
 594                                                          method_node);
 595
 596                         /*
 597                          * Delete any objects that were created by this method
 598                          * elsewhere in the namespace (if any were created).
 599                          * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
 600                          * deletion such that we don't have to perform an entire
 601                          * namespace walk for every control method execution.
 602                          */
 603                         if (method_desc->method.
 604                             info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
 605                                 acpi_ns_delete_namespace_by_owner(method_desc->
 606                                                                   method.
 607                                                                   owner_id);
 608                                 method_desc->method.info_flags &=
 609                                     ~ACPI_METHOD_MODIFIED_NAMESPACE;
 610                         }
 611                 }
 612         }
 613
 614         /* Decrement the thread count on the method */
 615
 616         if (method_desc->method.thread_count) {
 617                 method_desc->method.thread_count--;
 618         } else {
 619                 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
 620         }
 621
 622         /* Are there any other threads currently executing this method? */
 623
 624         if (method_desc->method.thread_count) {
 625                 /*
 626                  * Additional threads. Do not release the owner_id in this case,
 627                  * we immediately reuse it for the next thread executing this method
 628                  */
 629                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 630                                   "*** Completed execution of one thread, %u threads remaining\n",
 631                                   method_desc->method.thread_count));
 632         } else {
 633                 /* This is the only executing thread for this method */
 634
 635                 /*
 636                  * Support to dynamically change a method from not_serialized to
 637                  * Serialized if it appears that the method is incorrectly written and
 638                  * does not support multiple thread execution. The best example of this
 639                  * is if such a method creates namespace objects and blocks. A second
 640                  * thread will fail with an AE_ALREADY_EXISTS exception.
 641                  *
 642                  * This code is here because we must wait until the last thread exits
 643                  * before marking the method as serialized.
 644                  */
 645                 if (method_desc->method.
 646                     info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
 647                         if (walk_state) {
 648                                 ACPI_INFO((AE_INFO,
 649                                            "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
 650                                            walk_state->method_node->name.
 651                                            ascii));
 652                         }
 653
 654                         /*
 655                          * Method tried to create an object twice and was marked as
 656                          * "pending serialized". The probable cause is that the method
 657                          * cannot handle reentrancy.
 658                          *
 659                          * The method was created as not_serialized, but it tried to create
 660                          * a named object and then blocked, causing the second thread
 661                          * entrance to begin and then fail. Workaround this problem by
 662                          * marking the method permanently as Serialized when the last
 663                          * thread exits here.
 664                          */
 665                         method_desc->method.info_flags &=
 666                             ~ACPI_METHOD_SERIALIZED_PENDING;
 667                         method_desc->method.info_flags |=
 668                             ACPI_METHOD_SERIALIZED;
 669                         method_desc->method.sync_level = 0;
 670                 }
 671
 672                 /* No more threads, we can free the owner_id */
 673
 674                 if (!
 675                     (method_desc->method.
 676                      info_flags & ACPI_METHOD_MODULE_LEVEL)) {
 677                         acpi_ut_release_owner_id(&method_desc->method.owner_id);
 678                 }
 679         }
 680
 681         return_VOID;
 682 }