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

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2011-08-31 at 16:47 +0200, Felix Fietkau wrote:
> 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).

Huh? That frame should be buffered properly.

> >>  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.

Hm, yeah, I guess it wouldn't really matter.

johannes