On Wednesday 15 April 2009 21:24:55 Johannes Berg wrote:
> Right after associating, the AP sends us the EAPOL frame. We miss that
> frame, due to a race condition (we add the STA info for the AP a little
> too late and drop the frame because we don't know who it is from).
> 
> The AP of course retries the frame, a little later, but p54 misses the
> TIM bit -- see the ps.pkt file.
> 
> We should probably make that race window smaller somehow (stop the
> tasklet that is processing RX while processing assoc frames maybe?) but
> this is clearly foremost a p54 problem.

Well, I guess I figured out what's wrong: the hw spec.
So this patch might work on PCI & USB, but could break SPI devices.

Johannes, can you please test the attached patch?

BTW: there might be two problems:
1. if the timeout is too low the device might be fast enough to go into ps:
  -  either before sending a probe request
   (firmware reports tx_status TX_PSM, so the frame wasn't sent at all)
  - or the AP got the request and responded... 
    But the frame was lost, because probe responds are not buffered...

2. there was something wrong in ieee80211_rx_mgmt_beacon
    Sometimes the TIM was parsed, but thanks to
    local->hw.conf.dynamic_ps_timeout == 0
    mac80211 didn't issue a wakeup => so no data => disconnect

    But this bug maybe comes from the old RFCs from yesterday,
    as I didn't tried the final version yet...

Oh and one question:
Some time ago, I found some useful function that converted beacon_int TUs <-> msec,
do we still have them somewhere around and I'm just (temp) blind ?

Regards,
	Chr