diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index fd86737..28fdfd4 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -118,6 +118,7 @@
 
     static bool routedToA2dpOutput(audio_stream_type_t streamType);
 
+    // return status NO_ERROR implies *buffSize > 0
     static status_t getInputBufferSize(uint32_t sampleRate, audio_format_t format,
         audio_channel_mask_t channelMask, size_t* buffSize);