Back port "scan_freq" implementation to wpa supplicant 0.6.x

[Johannes Berg]

On Thu, 2010-12-16 at 14:14 +0100, Holger Schurig wrote:

> You confused mac80211 and cfg80211. Every mac80211-driver is also 
> controlled by cfg80211. But there are some non-mac80211-drivers that are 
> controlled by cfg80211 natively as well. And then there are some old, 
> outdated drivers that are still on WEXT. But the kernel has a WEXT-
> >cfg80211 gateway, where you can use cfg80211-based tools (e.g. "iw" or 
> wpa_supplicant -Dnl80211) with those drivers.

Err, I think that could be misunderstood -- the kernel has WEXT/cfg80211
compat code so that you can use new kernel drivers like drivers based on
mac80211 with old tools like iwconfig/wpa_supplicant -Dwext --
nl80211-based tools like iw/wpa_supplicant -Dnl80211 can only be used
with drivers that are implemented to the cfg80211 APIs.

johannes