Revert "ACPICA: fix AML mutex re-entrancy"

This reverts commit c0d127b56937c3e72c2b1819161d2f6718eee877.

These changes to AML locking were made to allow
Notify handlers to be called on the stack
and not deadlock.  However, that scheme turns
out to be flawed and was reverted by the previous commit,
so this commit restores the locking to it previous design.

Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/acpi/dispatcher/dsmethod.c b/drivers/acpi/dispatcher/dsmethod.c
index 1683e5c5b94c..1cbe61905824 100644
--- a/drivers/acpi/dispatcher/dsmethod.c
+++ b/drivers/acpi/dispatcher/dsmethod.c
@@ -231,8 +231,10 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
                  * Obtain the method mutex if necessary. Do not acquire mutex for a
                  * recursive call.
                  */
-                if (acpi_os_get_thread_id() !=
-                    obj_desc->method.mutex->mutex.owner_thread_id) {
+                if (!walk_state ||
+                    !obj_desc->method.mutex->mutex.owner_thread ||
+                    (walk_state->thread !=
+                     obj_desc->method.mutex->mutex.owner_thread)) {
                         /*
                          * Acquire the method mutex. This releases the interpreter if we
                          * block (and reacquires it before it returns)
@@ -246,14 +248,14 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
                         }
 
                         /* Update the mutex and walk info and save the original sync_level */
-                        obj_desc->method.mutex->mutex.owner_thread_id =
-                                acpi_os_get_thread_id();
 
                         if (walk_state) {
                                 obj_desc->method.mutex->mutex.
                                     original_sync_level =
                                     walk_state->thread->current_sync_level;
 
+                                obj_desc->method.mutex->mutex.owner_thread =
+                                    walk_state->thread;
                                 walk_state->thread->current_sync_level =
                                     obj_desc->method.sync_level;
                         } else {
@@ -567,7 +569,7 @@ acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
 
                         acpi_os_release_mutex(method_desc->method.mutex->mutex.
                                               os_mutex);
-                        method_desc->method.mutex->mutex.owner_thread_id = ACPI_MUTEX_NOT_ACQUIRED;
+                        method_desc->method.mutex->mutex.owner_thread = NULL;
                 }
         }