diff --git a/module_usb_audio/pdm_mics/pdm_mic.xc b/module_usb_audio/pdm_mics/pdm_mic.xc
index 4399f20b..6c856cc0 100644
--- a/module_usb_audio/pdm_mics/pdm_mic.xc
+++ b/module_usb_audio/pdm_mics/pdm_mic.xc
@@ -122,6 +122,7 @@ void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio)
     }
 
     /* Run user code */
+    /* TODO ideally processing done inplace - it then doesn't matter if it is run or not */
 #ifdef MIC_PROCESSING_USE_INTERFACE
     i_mic_process.transfer_buffers(current, output);
 #else