Unable to get hostapd working with minimal configuration file

[Aditya Bhave]

Hi,
I am new to using hostapd. I have the following config

1. Lenovo Thinkpad with Intel WGN card built in (wlan0) and Netgear 
Atheros card (ath0)
2. I installed hostapd as per instructions on the website.
3. My hostapd-minimal.conf file is

interface=ath0
driver=nl80211
ssid=test

However when I try and run hostapd, I get the following error


ayb at AdLenovoLaptop:~/Data/Work/CMU/PhD/Research/Code/hostapd-0.6.9/hostapd$ 
sudo ./hostapd ./hostapd-minimal.conf
Configuration file: ./hostapd-minimal.conf
Failed to set interface wlan0 to master mode.
nl80211 driver initialization failed.
ELOOP: remaining socket: sock=5 eloop_data=0x8db3848 user_data=(nil) 
handler=0x807c350
ayb at AdLenovoLaptop:~/Data/Work/CMU/PhD/Research/Code/hostapd-0.6.9/hostapd$

Can someone please help me with this?

thanks
regards,
Aditya Bhave