There was a bug with DragonRise Inc. Generic USB Joystick where the default control had shooting on the vertical axis across both d-sticks and movement was across the horizontals across both d-sticks. I found the running config printed in the log.txt and fixed it myself with trial and error. With this new config movement is on the left d-stick and shooting is on the right d-stick, all in the direction of tilt. The following is my new SDL2 game controller mapping string.

03000000790000000600000010010000,DragonRise Inc. Generic USB Joystick ,x:b3,a:b2,b:b1,y:b0,back:b8,start:b9,dpleft:h0.8,dpdown:h0.4,dpright:h0.2,dpup:h0.1,leftshoulder:b4,lefttrigger:b6,rightshoulder:b5,righttrigger:b7,leftstick:b10,rightstick:b11,leftx:a0,lefty:a1,rightx:a3,righty:a4,