I have read some post from guys on here saying that they are done with puberty because they have hair down there or there voice is done changing or because they are now 17. well I my self started puberty at 14 my voice was done changing by 15 I had hair down there by 16 but did not get facial hair until I was 18 and I was 5' 8" and did not finish puberty until I was about 19 or 20 when i jumped to my now heigth of 6'6" (oh just so you know I am now 22 years old.) so that does not mean much. and this may be deleted but I will not post my size because you will not believe me because I am bigger then pitts or what ever his name was being as I can not go back and look at it to be sure. (if he is telling the truth I know his pain being as I have only been about to have you know with five girls and only two could go longer then 5 minutes.) lets just say I was just over 6" long and 5 1/2 around at 15 and was up until 19 when I had a very large growth spurt.
Welcome to A2A, duke00x. It's hard to say when puberty "ends" - guys tend to keep getting hairier well into their 20s and perhaps beyond. A second penis growth spurt as you describe is not mentioned in textbooks but I've heard of many examples (though it's certainly unusual).