CONFIG_DRIVER_NL80211 option

Holger Schurig holgerschurig
Tue Dec 7 03:44:07 PST 2010

> Can anyone confirm what the function of "CONFIG_DRIVER_NL80211" option
> is? If i cotry to configure it, what else do i have to enable in
> defconfig?

This uses the new nl80211/cfg80211-method of configuring wireless 
devices. CFG80211 is the configuration API for the WLAN driver, while 
NL80211 is the interface between userspace and CFG80211 throught a 

All WLAN drivers that use MAC80211 (e.g. ath5k, ath9k, some intel 
drivers etc) use CFG80211 as a means of configuration. Usually only old, 
outdated or unmaintained WLAN drivers are using WEXT natively.

Note there there is a compatibility layer that tries to translate user-
space WEXT into kernel-space CFG80211. This, however, is relatively new 
and might still be buggy in corner-cases. Maybe your scan-frequency 
thingy is an issue.

And besides, cfg80211 allows for much more configation options, a saner 
interface, better link status reporting etc than WEXT.

So, if you have some recent 2.6.3x kernel, or if you're using compat-
wireless, you might simply forget WEXT. Compile wpa-supplicant with 
CONFIG_DRIVER_NL80211, get rid of "iwconfig" and friends, install "iw" 
and never look back.

For example, wpa_supplicant 0.7.x usually doesn't change the WEXT-based 
drivers, all the new stuff happens in the NL80211/CFG80211 area. And if 
you notice a bug, the chances that it will be fixed on the 
NL80211/CFG80211 area are much higher.


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