Re: [PATCH] mac80211: don't drop null frames during software scan

[Johannes Berg <johannes@sipsolutions.net>]

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On Sat, 2009-03-14 at 17:07 +0100, Johannes Berg wrote:
> On Sat, 2009-03-14 at 17:32 +0200, Kalle Valo wrote:
> > Johannes Berg wrote:
> > > On Sat, 2009-03-14 at 16:44 +0200, Kalle Valo wrote:
> > >> ieee80211_tx_h_check_assoc() was dropping everything else than probe
> > >> requests during software scan. So the null frame with the power save
> > >> bit was dropped and AP never received it. This meant that AP never
> > >> buffered any frames for the station during software scan.
> > >>
> > >> Fix this by allowing to transmit both probe request and null frames
> > >> during software scan. Tested with stlc45xx.
> > > 
> > > Would it make sense to reorder the scan code instead?
> > 
> > Perhaps. I chose this path only because it was simple to implement :) 
> > I'll take a look at the scan code in more detail and fix it there.
> 
> You're kinda right too, we want to disable the queues first, then set
> sw_scanning/notify the driver, and then send the nullfunc, I think. So
> it's either this patch, or iterating the interface list twice.

Related to this, shouldn't the driver notification:

        if (local->ops->sw_scan_start)
                local->ops->sw_scan_start(local_to_hw(local));

be moved to _after_ we stop the subif queues, disable beacons and send
the nullfunc? The sw_scan_complete is done before we re-enable
everything, so it seems logical that the start should be after we
disable it all.

Michael?

johannes

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