diff --git a/media/bufferpool/2.0/IAccessor.hal b/media/bufferpool/2.0/IAccessor.hal
index bd7094594e..ab7c02d458 100644
--- a/media/bufferpool/2.0/IAccessor.hal
+++ b/media/bufferpool/2.0/IAccessor.hal
@@ -68,5 +68,5 @@ interface IAccessor {
         generates (ResultStatus status, IConnection connection,
                    int64_t connectionId,
                    fmq_sync<BufferStatusMessage> toFmqDesc,
-                   fmq_sync<BufferInvalidationMessage> fromFmqDesc);
+                   fmq_unsync<BufferInvalidationMessage> fromFmqDesc);
 };
diff --git a/media/bufferpool/2.0/types.hal b/media/bufferpool/2.0/types.hal
index 7ce53b18bf..456e4aabda 100644
--- a/media/bufferpool/2.0/types.hal
+++ b/media/bufferpool/2.0/types.hal
@@ -100,7 +100,7 @@ struct BufferStatusMessage {
 struct BufferInvalidationMessage {
     /**
      * Buffers from fromBufferId to toBufferId must be invalidated.
-     * Both of fromBufferId and toBufferId are inclusive.
+     * fromBufferId is inclusive, but toBufferId is not inclusive.
      * If fromBufferId > toBufferID, wrap happens. In that case
      * the wrap is based on UINT32_MAX.
      */