apt hostadp does not support edimax ew-7811un
This build allows support for it
$ mkdir ~/src
$ cd ~/src
$ wget https://github.com/jenssegers/RTL8188-hostapd/archive/v1.1.tar.gz
$ tar -zxvf v1.1.tar.gz
$ cd RTL8188-hostapd-1.1/hostapd
$ sudo make
$ sudo make install