1 files changed, 10 insertions, 11 deletions

diff --git a/drivers/acpi/acpica/exmutex.c b/drivers/acpi/acpica/exmutex.c
index 2b0d722c984f..bb2efcfb81e2 100644
--- a/drivers/acpi/acpica/exmutex.c
+++ b/drivers/acpi/acpica/exmutex.c
@@ -359,6 +359,7 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 {
 	acpi_status status = AE_OK;
 	u8 previous_sync_level;
+	struct acpi_thread_state *owner_thread;
 
 	ACPI_FUNCTION_TRACE(ex_release_mutex);
 
@@ -366,9 +367,11 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
 
+	owner_thread = obj_desc->mutex.owner_thread;
+
 	/* The mutex must have been previously acquired in order to release it */
 
-	if (!obj_desc->mutex.owner_thread) {
+	if (!owner_thread) {
 		ACPI_ERROR((AE_INFO,
 			    "Cannot release Mutex [%4.4s], not acquired",
 			    acpi_ut_get_node_name(obj_desc->mutex.node)));
@@ -387,16 +390,13 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 	 * The Mutex is owned, but this thread must be the owner.
 	 * Special case for Global Lock, any thread can release
 	 */
-	if ((obj_desc->mutex.owner_thread->thread_id !=
-	     walk_state->thread->thread_id)
-	    && (obj_desc != acpi_gbl_global_lock_mutex)) {
+	if ((owner_thread->thread_id != walk_state->thread->thread_id) &&
+	    (obj_desc != acpi_gbl_global_lock_mutex)) {
 		ACPI_ERROR((AE_INFO,
 			    "Thread %p cannot release Mutex [%4.4s] acquired by thread %p",
 			    ACPI_CAST_PTR(void, walk_state->thread->thread_id),
 			    acpi_ut_get_node_name(obj_desc->mutex.node),
-			    ACPI_CAST_PTR(void,
-					  obj_desc->mutex.owner_thread->
-					  thread_id)));
+			    ACPI_CAST_PTR(void, owner_thread->thread_id)));
 		return_ACPI_STATUS(AE_AML_NOT_OWNER);
 	}
 
@@ -407,8 +407,7 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 	 * different level can only mean that the mutex ordering rule is being
 	 * violated. This behavior is clarified in ACPI 4.0 specification.
 	 */
-	if (obj_desc->mutex.sync_level !=
-	    walk_state->thread->current_sync_level) {
+	if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) {
 		ACPI_ERROR((AE_INFO,
 			    "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %u current %u",
 			    acpi_ut_get_node_name(obj_desc->mutex.node),
@@ -423,7 +422,7 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 	 * acquired, but are not released in reverse order.
 	 */
 	previous_sync_level =
-	    walk_state->thread->acquired_mutex_list->mutex.original_sync_level;
+	    owner_thread->acquired_mutex_list->mutex.original_sync_level;
 
 	status = acpi_ex_release_mutex_object(obj_desc);
 	if (ACPI_FAILURE(status)) {
@@ -434,7 +433,7 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
 
 		/* Restore the previous sync_level */
 
-		walk_state->thread->current_sync_level = previous_sync_level;
+		owner_thread->current_sync_level = previous_sync_level;
 	}
 	return_ACPI_STATUS(status);
 }