What's interesting is if this is the same John, in the 1880s census it gives us at least one potential (noting that census sources for this information can often be incorrect, but not always) source for information I have yet to seen, in the 1880 census he listes his parents as being born in Virginia.

So far the only information on John P's father John I've found is some earlier Madison County census records, land records as well (he seemed to own quite a few slaves and a moderate amount of land)... and I've talked with a fellow researcher who found a land record for John Bryant where it lists a chain carrier for a land record as John P (which helps confirm he's likely his son)... A Mason Bryant is also listed on the same land records so possibly another son of John (the eldest) or a brother potentially.