Re: [RFC] nl80211: don't require netdev UP for wdev

[Johannes Berg <johannes@sipsolutions.net>]

On Thu, 2012-05-10 at 12:47 -0700, Thomas Pedersen wrote:

> > We could, but that'd mean that it can be NULL if the user doesn't set
> > it, which seems a bit odd to me too and then the driver again would have
> > to sort it out. I'd prefer if we could sort it out in cfg80211 so the
> > driver (mac80211) is simpler.
> 
> For this, we can store a default channel and type in the default mesh config.

That would still break older userspace though, it would get the default
channel instead of the channel it set before, right?

> >> Also, with IBSS the desired channel is pushed to the driver along with
> >> the setup parameters. What do you think about calling
> >> __nl80211_set_channel() directly instead of relying on the cfg80211
> >> driver to handle this?
> >
> > No, that's certainly not possible. In IBSS the channel is just the
> > default channel if we don't find an IBSS. And in any case I'd rather
> > call set_channel less than more.
> 
> So cfg80211_set_freq() from cfg80211_join_mesh() is out, too?

I think we should just pass the channel to the join_mesh callback.

I just did this a bit for AP mode. Now, in AP mode we have one
advantage: we can rely on userspace setting the channel because
hostapd/wpa_s always does that. For mesh, we may not have that luxury?

For AP, it looks roughly like this:
http://p.sipsolutions.net/35913f571ea5bd43.txt

Maybe we can do something similar for mesh and mostly get rid of setting
the channel directly.

johannes