Re: NM fails to find access points

[Dan Williams <dcbw redhat com>]

On Fri, 2008-03-28 at 05:46 +0100, Rene Rask wrote:
> Dan Williams wrote:
> > On Thu, 2008-03-27 at 20:28 +0100, René Rask wrote:
> >>>> I can replicate this reliably by restarting the NM daemon. That always
> >>  >> leaves my AP off the list. I can also reliably find my AP again by using
> >>  >> "Create Net Wireless Network". When the new network fails to connect it
> >>  >> will always show my AP (and the rest of them) again. Sometimes it takes
> >>  >> a short while for it to appear, but it always does. Seems like a
> >>  >> scanning delay.
> >>  >>
> >>  >> Stopping NM, removing the wireless kernel module, insmod it and starting
> >>  >> NM again also has the effect of making it find my AP again.
> >>  >
> >>  > So this is pointing more towards a driver problem.  If you ever have to
> >>  > rmmod/insmod and stuff starts magically working again, it is almost
> >>  > always a driver issue.
> >>  >
> >>  > One more question: does your AP almost always show with 'iwlist', but
> >>  > usually never when doing the dbus-send to the supplicant?
> >>  >
> >>  > You might also try to do an 'iwlist' and then right afterwards, poke the
> >>  > supplicant with the dbus-send command and see if your AP is in the list.
> >>  > If the iwconfig and the supplicant-reported APs are quite different,
> >>  > then the supplicant is the problem.
> >>  >
> >>  > If you can poke around a bit with these things, let me know what happens
> >>  > so we can narrow down the issue further.
> >>  >
> >>
> >> I can't get this to work anymore. Last time wpa_supplicant wasn't 
> >> started a bootup so I started it manually.
> >>
> >> [root rr-laptop ~]# dbus-send --system 
> >> --dest=fi.epitest.hostap.WPASupplicant --print-reply 
> >> /fi/epitest/hostap/WPASupplicant/Interfaces/1 
> >> fi.epitest.hostap.WPASupplicant.Interface.scanResults
> >> Error org.freedesktop.DBus.Error.UnknownMethod: Method "scanResults" 
> >> with signature "" on interface 
> >> "fi.epitest.hostap.WPASupplicant.Interface" doesn't exist
> >>
> >> I can't restart wpa_supplicant unless I stop NM first. And I still can 
> >> get the dbus command to work.
> >>
> >> (a while later..)
> >> Hmm... now it works again. I was rmmodding/insmodding the iwl4965 modul 
> >> with debug and other paramaters and stopping/starting NM while this 
> >> happened.
> >>
> >> iwlist scan and the supplicant list match pretty good. Having the same 
> >> number of APs after a iwlist scan.
> >>
> >> iwlist doesn't always show my AP an neither does supplicant. But they 
> >> seem to agree on showing the same APs. The list of AP also goes from 3 
> >> to 14 found and anything in between.
> >> The scans have no effect on what is show in the applet.
> >>
> >> When the bug is in effect the number of found APs is 4-8 and my AP isn't 
> >> found by NM or supplicant.
> > 
> > But it _is_ seen by iwlist?  If it's not seen by iwlist either, then
> > it's a driver bug.  It's important to note that not every AP will be in
> > the scan results every time, because wireless is just hard and not
> > reliable.  However, I would certainly expect a non-hidden AP to show up
> > after 2 or 3 back-to-back scans at most.
> > 
> 
> No it isn't found at all when the bug is in effect. Doing "Create new.." 
> dance makes it show up again.
> 
> I tried many times. But it doesn't show up.

That points more to a driver bug then.  What kernel version, what
distro, and are you using the stock distro's driver or did you compile
your own from somewhere?

Dan