Re: [RFC] ath9k: Handle interface changes properly

[Felix Fietkau <nbd@openwrt.org>]

On 2011-01-14 7:53 PM, Rajkumar Manoharan wrote:
> On Fri, Jan 14, 2011 at 11:52:02PM +0530, Felix Fietkau wrote:
>>  On 2011-01-14 7:13 PM, Rajkumar Manoharan wrote:
>>  >  On Thu, Jan 13, 2011 at 10:19:38PM +0530, Felix Fietkau wrote:
>>  >>   On 2011-01-13 5:35 PM, Rajkumar Manoharan wrote:
>>  >>   >   Instead of setting opmde as AP for WDS, it is better to handle WDS
>>  >>   >   case in ath9k_hw.
>>  >>   Why? Right now I don't even see any NL80211_IFTYPE_WDS handling in
>>  >>   ath9k_hw, and I can't think of anything that should be handled
>>  >>   differently in ath9k_hw compared to the AP opmode.
>>  >  For WDS station, what should be the interface type? Forgive if I'm wrong.
>>  There is no WDS station opmode. 'WDS station' is a regular station
>>  interface with 4-addr mode enabled. It needs no special handling in ath9k.
> still not convinced. Then what is the point mac80211 is informing about
> WDS type to drivers. mac itself can pass it as AP type like what it
> is doing for p2p GO.
The WDS type is something else. If you have two APs, you can link them 
together with a separate WDS vif on each side pointing at the remote MAC 
address of the other node.
I think that when we use ah->opmode, we should only use it for very 
generic operating modes:

AP: no TSF sync, beacon tx can be enabled.
ADHOC: TSF sync against IBSS cell, beacon tx can be enabled
STATION: TSF sync against one AP, only station beacon timers for PS.

Only the above distinctions are relevant for ath9k_hw, everything else 
is handled by the driver/stack. There is no reason for adding extra 
checks to ath9k_hw for mesh and WDS, since they work best with 
ah->opmode set to AP, and there is nothing extra on the *hardware* side 
that should be configured there via a different opmode. That's why I 
think leaking the mac80211 interface types to ath9k_hw is a bad idea.

- Felix