Re: No ProbeResp - assume out of range

["Luis R. Rodriguez" <lrodriguez@atheros.com>]

On Sun, Nov 02, 2008 at 02:58:49PM -0800, Luis R. Rodriguez wrote:
> On Sun, Nov 2, 2008 at 2:42 PM, Tomas Winkler <tomasw@gmail.com> wrote:
> > On Mon, Nov 3, 2008 at 12:03 AM, Michael Buesch <mb@bu3sch.de> wrote:
> >> On Sunday 02 November 2008 22:05:56 Luis R. Rodriguez wrote:
> >>> I'm curious if others are getting this frequently as I am:
> >>>
> >>> No ProbeResp from current AP 00:DE:AD:BE:EE:FF - assume out of range
> >>>
> >>> I get this with ath5k and ath9k, can be triggered easily in ath5k by
> >>> doing a lot of consecutive:
> >>>
> >>> iwlist wlan0 scan
> >>>
> >>> I have to check if I can trigger this with ath9k by scanning too. We
> >>> were seeing this with ath9k but were thinking it was ath9k related as
> >>> it can be triggered on it after doing a large TX. Wondering if this is
> >>> more of a generic and mac80211 issue.
> >>
> >> IMO this is a mac80211 issue.
> >> mac80211 immediately assumes the connection is broken, if one probe-resp
> >> to a keekalife-proberequest is lost.
> >> So if you scan just after the request got sent, you'll never receive the response
> >> and mac80211 will terminate the connection.
> >> It should try a few times, instead, before blowing up things.
> >
> > I've seen this happening  in high traffic with some APs but it can be
> > also NIC issue. It needs to really investigate the sniffer capture I
> > wouldn't assume its only mac80211 issue.  Probe is issued only when RX
> > is not received for some time so there is some problem, nevertheless
> > monitoring beacons is a better approach from my experience.
> 
> Agreed if it can be NIC issue, but it seems to be a common issue now
> across a few drivers, not just ath5k/ath9k.
> 
> Hm, ieee80211_rx_mgmt_beacon() is not being hit with ath5k, something is fishy.

OK I found the issue with ath5k, no beacons were being passed at all, I'll post
a patch.

  Luis