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

[Michael Buesch <mb@bu3sch.de>]

On Saturday 14 March 2009 17:12:49 Johannes Berg wrote:
> 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.

For b43 it doesn't matter.

-- 
Greetings, Michael.