As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TAXIING OUT IN AUTO/NORM (FOR LESS THAN 1 MINUTE) DETECTED SMOKE. TURNED PACKS BACK TO LOW/LOW. NO ABNORMAL INDICATION ON PNEUMATIC PANEL BUT F/A REPORTED SMOKE IN CABIN & SMOKE IN LAV. TURNED OFF RECIRCS & PACKS, RETURNED TO GATE. SMOKE REMAINED BUT NO NEW SMOKE. FOUND PACKS TO BE FROZEN (ICED UP). DEFROSTED PACKS. COULDN'T DUPLICATE ANY PROBLEMS.