As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ON GROUND WAITING FOR PASSENGERS TO ARRIVE AND APU RUNNING FOR OVER AN HOUR NOTICED SMOKE/HAZE IN THE COCKPIT. AIRCRAFT WAS SHUTDOWN AND EMERGENCY SERVICES CONTACTED. MAINTENANCE ISOLATED DISCREPANCY TO THE APU. APU SYSTEM WAS DEFERRED PER GAMA LLC MEL.