We are flying from the US (EWR) to LIS. I assume passport control/immigration/customs will be at the LIS airport. On the return we fly from LIS to LHR to SFO. Do we go through passport control at Lisbon airport or Heathrow? We only have a connecting time of 1 hour 55 minutes, assuming TAP is on time into LHR. Is that enough time? The Heathrow airport website has a connection model that says 60 minutes to connect, and it describes security checkpoint but not passport control.