Re: [PATCH] ipw2200: expire and use oldest BSS on adhoc create

[Dan Williams <dcbw@redhat.com>]

On Fri, 2008-05-30 at 08:56 +0800, Zhu Yi wrote:
> On Thu, 2008-05-29 at 14:38 -0400, Dan Williams wrote:
> > If there are no networks on the free list, expire the oldest one when
> > creating a new adhoc network.  Because ipw2200 and the ieee80211 stack
> > don't actually cull old networks and place them back on the free list
> > unless they are needed for new probe responses, over time the free list
> > would become empty and creating an adhoc network would fail due to the !
> > list_empty(...) check.
> > 
> > Signed-off-by: Dan Williams <dcbw@redhat.com>
> 
> ACK. Looks like you are doing stress testing to create/delete ad-hoc
> networks (> 128) ;-)

Was in a shuttle bus at the time, trying to get connection sharing
working between 3G and an ad-hoc network, and couldn't figure out why
the driver kept refusing to create the new IBSS...

Dan

> Thanks,
> -yi
> 
> > diff --git a/drivers/net/wireless/ipw2200.c b/drivers/net/wireless/ipw2200.c
> > index d74c061..db2bf46 100644
> > --- a/drivers/net/wireless/ipw2200.c
> > +++ b/drivers/net/wireless/ipw2200.c
> > @@ -7558,8 +7558,31 @@ static int ipw_associate(void *data)
> >  	    priv->ieee->iw_mode == IW_MODE_ADHOC &&
> >  	    priv->config & CFG_ADHOC_CREATE &&
> >  	    priv->config & CFG_STATIC_ESSID &&
> > -	    priv->config & CFG_STATIC_CHANNEL &&
> > -	    !list_empty(&priv->ieee->network_free_list)) {
> > +	    priv->config & CFG_STATIC_CHANNEL) {
> > +		/* Use oldest network if the free list is empty */
> > +		if (list_empty(&priv->ieee->network_free_list)) {
> > +			struct ieee80211_network *oldest = NULL;
> > +			struct ieee80211_network *target;
> > +			DECLARE_MAC_BUF(mac);
> > +
> > +			list_for_each_entry(target, &priv->ieee->network_list, list) {
> > +				if ((oldest == NULL) ||
> > +				    (target->last_scanned < oldest->last_scanned))
> > +					oldest = target;
> > +			}
> > +
> > +			/* If there are no more slots, expire the oldest */
> > +			list_del(&oldest->list);
> > +			target = oldest;
> > +			IPW_DEBUG_ASSOC("Expired '%s' (%s) from "
> > +					"network list.\n",
> > +					escape_essid(target->ssid,
> > +						     target->ssid_len),
> > +					print_mac(mac, target->bssid));
> > +			list_add_tail(&target->list,
> > +				      &priv->ieee->network_free_list);
> > +		}
> > +
> >  		element = priv->ieee->network_free_list.next;
> >  		network = list_entry(element, struct ieee80211_network, list);
> >  		ipw_adhoc_create(priv, network);
> 
> --
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