Breastfeeding total time during day

So my baby feeds for 7-12 mins on one breast and falls asleep for 2 hours. He will do what I call a superfeed after 9 pm where he'll feed for 1 HR until 11 pm. He's been doing this since he turned about 2 weeks old and is now 1.5 months old. Is this normal? I keep reading about how babies breastfeed from 25-40 mins and I'm concerned. Baby has been gaining weight and is 10 pounds, he poops and pees normally and the pediatrician congratulated me on that at least. According to info logged in the app, he feeds a total of 2 hours and a half to 3 hours a day. Is this enough?