ACPICA: Update comments for acquire/release mutex interfaces

pdate comments for acquire/release mutex interfaces

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Bob Moore 2008-04-10 19:06:37 +04:00 committed by Len Brown
parent dbaaa95675
commit 91e38d10b2

View File

@ -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;