diff options
| -rw-r--r-- | drivers/acpi/acpica/exmutex.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/acpi/acpica/exmutex.c b/drivers/acpi/acpica/exmutex.c index d7cb030a21f..77a592aa53c 100644 --- a/drivers/acpi/acpica/exmutex.c +++ b/drivers/acpi/acpica/exmutex.c @@ -83,6 +83,15 @@ void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc) if (obj_desc->mutex.prev) { (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next; + + /* + * Migrate the previous sync level associated with this mutex to the + * previous mutex on the list so that it may be preserved. This handles + * the case where several mutexes have been acquired at the same level, + * but are not released in opposite order. + */ + (obj_desc->mutex.prev)->mutex.original_sync_level = + obj_desc->mutex.original_sync_level; } else { thread->acquired_mutex_list = obj_desc->mutex.next; } @@ -349,6 +358,7 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, struct acpi_walk_state *walk_state) { acpi_status status = AE_OK; + u8 previous_sync_level; ACPI_FUNCTION_TRACE(ex_release_mutex); @@ -404,14 +414,21 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, return_ACPI_STATUS(AE_AML_MUTEX_ORDER); } + /* + * Get the previous sync_level from the head of the acquired mutex list. + * This handles the case where several mutexes at the same level have been + * acquired, but are not released in reverse order. + */ + previous_sync_level = + walk_state->thread->acquired_mutex_list->mutex.original_sync_level; + status = acpi_ex_release_mutex_object(obj_desc); if (obj_desc->mutex.acquisition_depth == 0) { /* Restore the original sync_level */ - walk_state->thread->current_sync_level = - obj_desc->mutex.original_sync_level; + walk_state->thread->current_sync_level = previous_sync_level; } return_ACPI_STATUS(status); } |