Travis Barker says he's been blown away by the inmates battling the Los Angeles wildfires ... telling us it's proof people who've made bad decisions can still do good things.

The Blink-182 drummer joined us on "TMZ Live" Thursday and we asked him about this week's visit with a group of prisoners working 24-hour shifts as firefighters.

Travis was super inspired when he heard about the nonviolent security inmates battling the blazes for a dollar an hour ... and he wants to use his platform to give them the appreciation they deserve.

TB says a lot of these inmates got in trouble when they were young, and the fires are giving them an avenue to do something positive with their lives ... instead of rotting away in a cell.

Kim Kardashian, Travis' sister-in-law, has also been advocating for these inmate firefighters ... trying to raise their measly wages ... and Travis says he hopes some of these guys can become real firefighters one day. He says they're heroes along with all the other first responders.

Travis' visit clearly left a big impression ... catch the full interview on "TMZ Live."