DPL: improve debug message

Author: ktf

Framework/Core/src/DataProcessingDevice.cxx

@@ -1847,7 +1847,8 @@ void DataProcessingDevice::handleData(ServiceRegistryRef ref, InputChannelInfo&
       // This is because in principle we should track the size of each of
       // the parts and sum it up. Not for now.
       O2_SIGNPOST_ID_FROM_POINTER(pid, parts, headerData);
-      O2_SIGNPOST_START(parts, pid, "parts", "Processing DataHeader with splitPayloadParts %d and splitPayloadIndex %d", dh->splitPayloadParts, dh->splitPayloadIndex);
+      O2_SIGNPOST_START(parts, pid, "parts", "Processing DataHeader %{public}-4s/%{public}-16s/%d with splitPayloadParts %d and splitPayloadIndex %d",
+                        dh->dataOrigin.str, dh->dataDescription.str, dh->subSpecification, dh->splitPayloadParts, dh->splitPayloadIndex);
       if (!dph) {
         insertInputInfo(pi, 2, InputType::Invalid, info.id);
         O2_SIGNPOST_EVENT_EMIT_ERROR(device, cid, "handle_data", "Header stack does not contain DataProcessingHeader");