I set up Wireless AP + Eth0 - Wlan0 bridging and samba server on Cubietruck A20.
I binded samba to lo, wlan0, and eth0:
interfaces = lo wlan0 eth0
bind interfaces only = yes
If I boot up with Ethernet cable connected then samba is OK on both eth and wlan.
But if Ethernet cable is unplugged then samba is not accessible via wlan however it sturts up and running.
Here's a line from smbd.log.
STATUS=daemon 'smbd' finished starting up and ready to serve connectionsopen_socket_in(): setsockopt: SO_REUSEPORT = true on port 445 failed with error = Protocol not available
Perhaps wlan is not working.
See here for instructions: