On Fri, 2009-03-20 at 18:04 +0800, Jeff Chua wrote:
> On Fri, Mar 20, 2009 at 4:32 PM, Johannes Berg
> <johannes@sipsolutions.net> wrote:
> > 1) It can't be before iwconfig which will result in "SET failed on
> > device wlan0 ; Device or resource busy".
> >  So your point 1) confuses me. Can you
> > explain that a little more?
> 
> This is what happened ...
> 
> # modprobe -r iwlagn
> # modprobe iwlagn
> # ifconfig wlan0 up
> # iwconfig wlan0 mode Managed
> Error for wireless request "Set Mode" (8B06) :
>     SET failed on device wlan0 ; Device or resource busy.

Oh, ok, yes, you cannot change the mode while the interface is up.
Though I guess setting it to the same mode should be accepted. Not that
it matters, the default mode is "managed" anyway.

> > As for 2), that is very very strange since ap auto channel auto is the
> > default, so saying that before you do anything else should do anything
> > at all.
> >
> > I suspect something is going on in the driver because the ifconfig order
> > matters and for mac80211, it shouldn't make a difference when the state
> > machine is really started. I'll probably need to try to reproduce this,
> > but to be honest between the varying failure modes, undefined wireless
> > extensions semantics, etc. I'm not very confident I can.
> 
> I'll try all the different combination again for 2.6.28, and see if
> it's the same, and on the other AP that seems harder to associate (but
> works well in 2.6.28, and other OSs include Nokia phones ... so I
> don't think it's the AP problem ... because it's been around a while
> and gone thru many 2.6.xx).

Yeah, I have to admit that an AP problem doesn't make much sense -- but
the entire failure mode doesn't make much sense to me so far.

> It worked so well before that I didn't even bother to think twice, and
> I may have made silly mistakes along the way, so pardon me if I
> confused you.

No worries. It really should still work well. Can I convince you to try
getting the packet dump I asked for in another mail?

johannes