Something wrong with my porcupine puffer?

this morning i went to check on my fish and i thought my puffer was dead but i showed him the food cup and he immediately got up thinking i was going to feed him like he always does when he sees it. i took the cup away and he acted dead again. i dont know if he is just lazy or if hes sick. he never really was an active swimmer and i always thought this was because they are nocturnal and he is usually more active at night. i have had him in my 110 gallon tank for about 10 months now and he was always lazy but i never thought he was dead before. i did notice white spots on him but they have been there for well over a month and in my experience with salt water ich he would be dead by now if he had it. they also seem to come and go and they are not in the usual places like the fins or near the gills which is where i find ich to be the worst. his eyes look clear and healthy also. he also eats like a pig as usual. he did have ich before i bought him at the pet shop but they held onto him for me and got him better. he was extremely thin when i bought him and now he is nice and fat. so do you think he is sick or just being very bummish today? thanks for your help!