Re: [RFC] ath9k: Handle interface changes properly

[Felix Fietkau <nbd@openwrt.org>]

On 2011-01-14 8:29 PM, Ben Greear wrote:
> On 01/14/2011 11:24 AM, Rajkumar Manoharan wrote:
>>  On Sat, Jan 15, 2011 at 12:36:42AM +0530, Felix Fietkau wrote:
>>>  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.
>>  Thanks for your detailed explanation. And meanwhile Ben is also
>>  fixing hw mode based on vif counter. It would be better if he make
>>  use this thread and address the same.
>>
>>  Ben,
>>  Any comments.
>
> If all I need to do is to treat WDS and MESH like an AP, that shouldn't
> be too hard.
>
> Does WDS need a beacon?
No

> Is there any limitations to the number of WDS vifs allowed, including
> combinations with other VIF types?
I don't think so.

- Felix