mac80211: split out and decrease probe wait time

The time we wait for a probe response after probing an AP due to
beacon loss is currently the same as the monitoring interval, 2s.
This is far too long, APs should respond to probes within a
fraction of that time. To be able to adjust both values, add a
new constant IEEE80211_PROBE_WAIT, use it for checking the probe
response, and adjust it down to 200ms instead of 2 seconds.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/mlme.c

@@ -33,6 +33,7 @@
 #define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
 #define IEEE80211_ASSOC_MAX_TRIES 3
 #define IEEE80211_MONITORING_INTERVAL (2 * HZ)
+#define IEEE80211_PROBE_WAIT (HZ / 20)
 #define IEEE80211_PROBE_IDLE_TIME (60 * HZ)
 #define IEEE80211_RETRY_AUTH_INTERVAL (1 * HZ)
 
@@ -1205,7 +1206,7 @@ void ieee80211_beacon_loss_work(struct work_struct *work)
 	ieee80211_send_probe_req(sdata, ifmgd->bssid, ifmgd->ssid,
 				 ifmgd->ssid_len, NULL, 0);
 
-	mod_timer(&ifmgd->timer, jiffies + IEEE80211_MONITORING_INTERVAL);
+	mod_timer(&ifmgd->timer, jiffies + IEEE80211_PROBE_WAIT);
 }
 
 void ieee80211_beacon_loss(struct ieee80211_vif *vif)
@@ -1242,7 +1243,7 @@ static void ieee80211_associated(struct ieee80211_sub_if_data *sdata)
 	}
 
 	if ((ifmgd->flags & IEEE80211_STA_PROBEREQ_POLL) &&
-	    time_after(jiffies, sta->last_rx + IEEE80211_MONITORING_INTERVAL)) {
+	    time_after(jiffies, sta->last_rx + IEEE80211_PROBE_WAIT)) {
 		printk(KERN_DEBUG "%s: no probe response from AP %pM "
 		       "- disassociating\n",
 		       sdata->dev->name, ifmgd->bssid);