RADIUS server setup

[Pujeri, Prabhakar]

Hi all,
I installed hostapd from Debian package 
And I want to use this as RADIUS server so 
I configured its config file(it in /etc/hostapd/hostapd.conf)
And I run it like this 
hostapd /etc/hostapd/hostapd.conf 

but I am getting error like 
ioctl[PRISM2_IOCTL_PRISM2_PARAM]:operation not supported 

it looks like I need to install some driver but I don't know which one 
and I am using Linksys AP wired connection with RADIUS server

-prabhakar