Re: [PATCH v5] mac80211: implement multi-vif in-place reservations

[Michal Kazior <michal.kazior@tieto.com>]

On 7 May 2014 13:09, Johannes Berg <johannes@sipsolutions.net> wrote:
> On Wed, 2014-05-07 at 12:38 +0200, Michal Kazior wrote:
>
>> I was actually thinking of just providing the bare minimum to fulfill
>> requirements for the CSA case: int foo(*hw, **vifs, n_vifs, *oldctx,
>> *newctx, flags).
>>
>> Having an array of transactions passed through a single call seems
>> more robust and cleaner. Naiive drivers might just iterate over each
>> entry while more complex drivers might examine the whole request and
>> detect chanctx swapping.
>
> Not sure what you mean by "detect chanctx swapping" - the flags would
> indicate that anyway, no? In any case, I like this better than a more
> general transaction API I think, it's easier for the driver
> implementation and clearer as to what needs to be done/supported.

You could submit a transaction sequence:
 - new chanctx2
 - switch vif1 chanctx1->chanctx2
 - switch vif2 chanctx1->chanctx2
 - remove chanctx1

Driver could infer this is a channel switch and depending on it's
capabilities/limitations perform some extra actions or just map it to
internal commands 1:1.


Michał