Re: [RFC v3] initial channel context implementation

Michal Kazior <michal.kazior@xxxxxxxxx> · Thu, 28 Jun 2012 10:54:55 +0200

Johannes Berg wrote:

On Thu, 2012-06-28 at 09:01 +0200, Michal Kazior wrote:

Hmm.. Yeah we need to now, sort of. FullMAC drivers could suffer, but we
could drop connections upon CSA in mac80211 for the time being.

cfg80211 could provide:
    * cfg80211_sta_can_switch_chan
    * cfg80211_sta_ch_switch_notify

mac80211 could then be able to know whether num_different_channels has
been reached (cfg80211_sta_can_switch_chan) and eventually notify upon
channel switch (cfg80211_sta_ch_switch_notify).

Channel switch would happen if either:
    * cfg80211_sta_can_switch_chan is true
    * channel context for target CSA channel already exists

I'm just unsure about the current_bss thing - whether we should e.g.
initiate a scan to update it, or can we shamelessly update the channel
in the structure directly?

Today mac80211 just updates it, yeah.

Should I send the ,,respect channels in iface combinations'' as a
[PATCH] now, or should the CSA issue (in cfg80211) be addressed first?

Good question. Even if we don't do CSA first, I guess we don't really
break anything right now, do we? And if the driver/mac80211 just changes
the channel, that means it could seem to go over the limit of 1 channel
but things just break down like they do today?

Yeah, probably. We might end up in a funny state (e.g. rejecting some 

actions which would otherwise be possible) after doing CSA until we 

disconnect.

I guess I'd like to have the CSA stuff addressed, but it seems we
haven't really closed on the best way yet, and I don't want to hold off
your work for it for too long?

If you're okay with that then I'll just send out the [PATCH].

--
Pozdrawiam / Best regards, Michal Kazior.

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