Blake T. Ostler argues that Joseph did not teach an eternal chain of Gods; Brigham did, but it was tied to his "unsound doctrine" of Adam-God.
Blake T. Ostler, Exploring Mormon Thought, 4 vols. (Salt Lake City: Greg Kofford Books, 2006), 2:451n.28
While Joseph Smith did not have such a view of an eternal chain of gods, it appears to me that Brigham Young did. However, it seems to me that his view of the chain of gods is tied up in his Adam-God theology and ought to be rejected as unsound doctrine by Latter-day Saints.