diff options
| -rw-r--r-- | drivers/acpi/executer/exmutex.c | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/drivers/acpi/executer/exmutex.c b/drivers/acpi/executer/exmutex.c index 0bebe751aac..32f24a8fba5 100644 --- a/drivers/acpi/executer/exmutex.c +++ b/drivers/acpi/executer/exmutex.c @@ -134,7 +134,16 @@ acpi_ex_link_mutex(union acpi_operand_object *obj_desc, * * RETURN: Status * - * DESCRIPTION: Acquire an AML mutex, low-level interface + * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common + * path that supports multiple acquires by the same thread. + * + * MUTEX: Interpreter must be locked + * + * NOTE: This interface is called from three places: + * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator + * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the + * global lock + * 3) From the external interface, acpi_acquire_global_lock * ******************************************************************************/ @@ -174,7 +183,7 @@ acpi_ex_acquire_mutex_object(u16 timeout, return_ACPI_STATUS(status); } - /* Have the mutex: update mutex and save the sync_level */ + /* Acquired the mutex: update mutex object */ obj_desc->mutex.thread_id = thread_id; obj_desc->mutex.acquisition_depth = 1; @@ -211,7 +220,7 @@ acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, return_ACPI_STATUS(AE_BAD_PARAMETER); } - /* Sanity check: we must have a valid thread ID */ + /* Must have a valid thread ID */ if (!walk_state->thread) { ACPI_ERROR((AE_INFO, @@ -221,7 +230,7 @@ acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, } /* - * Current Sync level must be less than or equal to the sync level of the + * Current sync level must be less than or equal to the sync level of the * mutex. This mechanism provides some deadlock prevention */ if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) { @@ -236,6 +245,9 @@ acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, obj_desc, walk_state->thread->thread_id); if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) { + + /* Save Thread object, original/current sync levels */ + obj_desc->mutex.owner_thread = walk_state->thread; obj_desc->mutex.original_sync_level = walk_state->thread->current_sync_level; @@ -259,6 +271,16 @@ acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, * RETURN: Status * * DESCRIPTION: Release a previously acquired Mutex, low level interface. + * Provides a common path that supports multiple releases (after + * previous multiple acquires) by the same thread. + * + * MUTEX: Interpreter must be locked + * + * NOTE: This interface is called from three places: + * 1) From acpi_ex_release_mutex, via an AML Acquire() operator + * 2) From acpi_ex_release_global_lock when an AML Field access requires the + * global lock + * 3) From the external interface, acpi_release_global_lock * ******************************************************************************/ @@ -294,6 +316,8 @@ acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc) acpi_os_release_mutex(obj_desc->mutex.os_mutex); } + /* Clear mutex info */ + obj_desc->mutex.thread_id = 0; return_ACPI_STATUS(status); } @@ -348,7 +372,7 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, return_ACPI_STATUS(AE_AML_NOT_OWNER); } - /* Sanity check: we must have a valid thread ID */ + /* Must have a valid thread ID */ if (!walk_state->thread) { ACPI_ERROR((AE_INFO, @@ -370,7 +394,7 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, status = acpi_ex_release_mutex_object(obj_desc); - /* Restore sync_level */ + /* Restore the original sync_level */ walk_state->thread->current_sync_level = obj_desc->mutex.original_sync_level; |