mac80211: change number of pre-assoc scans

This patch fixes noticed problem in noisy environments of 50+ APs
that scan fails to find the requested AP on first try, which
leads to connection refusal. second scan has empirically proven to fix
this problem in almost all cases.
Signed-off-by: NRon Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: NEsti Kummer <ester.kummer@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/ieee80211_i.h

@@ -361,7 +361,9 @@ struct ieee80211_if_sta {
 
 	struct sk_buff_head skb_queue;
 
-	int auth_tries, assoc_tries;
+	int assoc_scan_tries; /* number of scans done pre-association */
+	int auth_tries; /* retries for auth req */
+	int assoc_tries; /* retries for assoc req */
 
 	unsigned long request;
 

net/mac80211/mlme.c

@@ -34,6 +34,7 @@
 #include "led.h"
 #include "mesh.h"
 
+#define IEEE80211_ASSOC_SCANS_MAX_TRIES 2
 #define IEEE80211_AUTH_TIMEOUT (HZ / 5)
 #define IEEE80211_AUTH_MAX_TRIES 3
 #define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
@@ -596,6 +597,7 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
 {
 	if (deauth)
 		ifsta->auth_tries = 0;
+	ifsta->assoc_scan_tries = 0;
 	ifsta->assoc_tries = 0;
 	ieee80211_set_associated(sdata, ifsta, 0);
 }
@@ -3405,7 +3407,9 @@ static void ieee80211_sta_reset_auth(struct ieee80211_sub_if_data *sdata,
 		ifsta->auth_alg = WLAN_AUTH_OPEN;
 	ifsta->auth_transaction = -1;
 	ifsta->flags &= ~IEEE80211_STA_ASSOCIATED;
-	ifsta->auth_tries = ifsta->assoc_tries = 0;
+	ifsta->assoc_scan_tries = 0;
+	ifsta->auth_tries = 0;
+	ifsta->assoc_tries = 0;
 	netif_carrier_off(sdata->dev);
 }
 
@@ -3510,7 +3514,8 @@ static int ieee80211_sta_config_auth(struct ieee80211_sub_if_data *sdata,
 		ieee80211_sta_reset_auth(sdata, ifsta);
 		return 0;
 	} else {
-		if (ifsta->state != IEEE80211_STA_MLME_AUTHENTICATE) {
+		if (ifsta->assoc_scan_tries < IEEE80211_ASSOC_SCANS_MAX_TRIES) {
+			ifsta->assoc_scan_tries++;
 			if (ifsta->flags & IEEE80211_STA_AUTO_SSID_SEL)
 				ieee80211_sta_start_scan(sdata, NULL, 0);
 			else