Re: [RFC 4/5] cfg80211: add DFS region capability support

[Simon Wunderlich <sw@simonwunderlich.de>]

> On Thu, Nov 14, 2013 at 4:29 PM, Johannes Berg
> 
> <johannes@sipsolutions.net> wrote:
> > On Thu, 2013-11-14 at 07:33 -0800, Luis R. Rodriguez wrote:
> >> > Still doesn't make sense - HANDLE_DFS means "I'll react to radar
> >> > detection events and will do the CSA". It has absolutely nothing to do
> >> > with DFS regions. Please keep those things separate.
> >> 
> >> How you deal with radar detection is completely dependent on the DFS
> >> region, no?
> > 
> > You're missing *my* point :-)
> > 
> > Radar *detection* is region-dependent.
> > 
> > What happens *after* that (announce a channel switch, etc.) isn't at
> > all.
> 
> Sorry, I misread the documentation then, so HANDLE_DFS *does* not mean
> userspace will implement the radar detection in userspace?
> 

Right, it does not mean userspace implements radar detection/pattern 
matching/etc.

HANDLE_DFS only means that userspace lets the kernel know that it will react 
to nl80211-dfs-radar events (these only contain "i detected a radar on freq 
XXX" [1] and similar) and that it will do a channel switch (CSA) in this case 
to move away.

We still assume that the radar detection/pattern matching/etc, which is indeed 
region-specific, is done in the drivers (as done for ath9k now) or by other 
means independent of this HANDLE_DFS attribute.

Cheers,
    Simon

[1] http://lxr.free-electrons.com/source/include/uapi/linux/nl80211.h#L3836