I was on a DFW/SFO flight a few months back when the pilot made a hard climbing left turn after getting onto final approach. He came on and said there was a flight control problem and that we would be met by the fire trucks. It all worked out but after we pulled into the gate he came on and said they got a flap discrepancy warning indicating the flaps were not coming down symmetrically. It was nice to know what happened but I was prepared to just walk up to the cockpit and ask as we were deplaning.