[pkg-wpa-devel] [PATCH] add event hysteresis

[Kel Modderman]

On Monday 25 September 2006 00:06, Jason Lunz wrote:
> On Sun, Sep 24, 2006 at 11:53:58PM +1000, Kel Modderman wrote:
> > Jason, how does the following patch look to you?
>
> looks like it should work.
>
> >  #####################################################################
> > +## hysteresis checking
> > +# Networking tools such as dhcp clients used with ifupdown can
> > +# synthesize artificial ACTION events, particuarly just after a
> > +# DISCONNECTED event is encountered immediately after a CONNECTED
> > +# event. This can lead to infinite event loops, and in extreme cases
> > +# has the potential to cause system instability.
>
> minor nitpick: In my case, the loop was provoked by an
> DISCONNECTED/CONNECTED pair immediately after resume. Also, I don't know
> what system instability you're referring to - maybe a buggy wireless
> driver can be stressed by repeated reassociation? 
> though, i'd say the system's already unstable.

Yes, I have reproduced this before with a buggy madwifi link. The loop caused 
complete lockup (assume it did stress a crappy piece of code, which is not 
uncommon to find in madwifi).

I've also induced such a loop with ipw2200 before, under certain conditions, 
and with an older version of the module that crapped out with firmware errors 
every other minute.

The above blurb has been adjusted for commit, and the system instability 
warning serves as a flag of importance for those basic hysteresis checking 
functions.

>
> I agree it would be nice to do something a little more sophisticated,
> but this works at least.

Ok. I agree. Thanks for patch + comments.

Thanks, Kel.