Re: [PATCH] mac80211: retry sending failed BAR frames later instead of tearing down aggr

[Felix Fietkau <nbd@openwrt.org>]

On 2011-08-31 2:15 PM, Johannes Berg wrote:
> On Sun, 2011-08-28 at 21:11 +0200, Felix Fietkau wrote:
>>  Unfortunately failed BAR tx attempts happen more frequently than I
>>  expected, and the resulting aggregation teardowns cause performance
>>  issues, as the aggregation session does not always get re-established
>>  properly.
>
> I find this curious. How can tons of traffic go through, but BAR frames
> fail? These are unicast and should be retried a bunch...
I think it mostly happens when the client goes to powersave (triggered 
by background scans, etc).

>>  Instead of tearing down the entire aggr session, we can simply store the
>>  SSN of the last failed BAR tx attempt, wait for the first successful
>>  tx status event, and then send another BAR with the same SSN.
>
> So what if it keeps failing? I think eventually we'd want to kill the
> session?
If it keeps failing, then the connection is probably so bad that it 
doesn't matter if we kill the session or not.

- Felix