Its Ok, the white smoke is the beginning of the lighting cycle. Then once the wood has enough heat to smolder it burns more completely. Yes you could be using too much if you are using more than a good sized handful at atime.
But see, once your box comes up to temp, the heating coil which is what supply's the heat to ignite/smolder the chips, the heater element modulates to try and maintain temperature. On/off, on/off, and unless it fires it early in the preheat cycle it may not have enough high heat long enough to smolder the chips.
Once you finish that initial lighting cycle, you can then regulate the vent so the coil works less, using less electricity and retaining a longer smoking cycle from the chips by closing the vent a small amount, maybe half way.
Also, know that using the internal temperature (IT), which is how most things are gauged around here, the optimal IT for smoke absorption is 100 to 145 IT. Yes it still smokes above and below, but the food absorbs the smoke at a lesser efficiency. You don't need to smoke for 12 to 24 hours while cooking the meat unless you just want to do so.
BTW you can also use a aux. smoke generator, like an AMPs sold by one of the sites sponsors. Its allows you to leave the door closed and your meat to smoke as intended.
Good luck and hope you have a great 4th!!
