mac80211: Retry probe request few times

Retry 5 times  (chosen arbitary ), before assuming
that station is out of range.

Fixes frequent disassociations while connected to weak,
and sometimes even strong access points.

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

2 files changed, 31 insertions, 12 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 316825be2019..8d790e40f3e9 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -280,6 +280,7 @@ struct ieee80211_if_managed {
         struct work_struct beacon_loss_work;
 
         unsigned long probe_timeout;
+        int probe_send_count;
 
         struct mutex mtx;
         struct ieee80211_bss *associated;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index c9e4091cd2bb..ccd5c7a1749f 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -31,6 +31,7 @@
 #define IEEE80211_AUTH_MAX_TRIES 3
 #define IEEE80211_ASSOC_TIMEOUT (HZ / 5)
 #define IEEE80211_ASSOC_MAX_TRIES 3
+#define IEEE80211_MAX_PROBE_TRIES 5
 
 /*
  * beacon loss detection timeout
@@ -1153,11 +1154,24 @@ void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
                   round_jiffies_up(jiffies + IEEE80211_CONNECTION_IDLE_TIME));
 }
 
+static void ieee80211_mgd_probe_ap_send(struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+        const u8 *ssid;
+
+        ssid = ieee80211_bss_get_ie(&ifmgd->associated->cbss, WLAN_EID_SSID);
+        ieee80211_send_probe_req(sdata, ifmgd->associated->cbss.bssid,
+                                 ssid + 2, ssid[1], NULL, 0);
+
+        ifmgd->probe_send_count++;
+        ifmgd->probe_timeout = jiffies + IEEE80211_PROBE_WAIT;
+        run_again(ifmgd, ifmgd->probe_timeout);
+}
+
 static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
                                    bool beacon)
 {
         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
-        const u8 *ssid;
         bool already = false;
 
         if (!netif_running(sdata->dev))
@@ -1200,18 +1214,12 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
         if (already)
                 goto out;
 
-        ifmgd->probe_timeout = jiffies + IEEE80211_PROBE_WAIT;
-
         mutex_lock(&sdata->local->iflist_mtx);
         ieee80211_recalc_ps(sdata->local, -1);
         mutex_unlock(&sdata->local->iflist_mtx);
 
-        ssid = ieee80211_bss_get_ie(&ifmgd->associated->cbss, WLAN_EID_SSID);
-        ieee80211_send_probe_req(sdata, ifmgd->associated->cbss.bssid,
-                                 ssid + 2, ssid[1], NULL, 0);
-
-        run_again(ifmgd, ifmgd->probe_timeout);
-
+        ifmgd->probe_send_count = 0;
+        ieee80211_mgd_probe_ap_send(sdata);
  out:
         mutex_unlock(&ifmgd->mtx);
 }
@@ -2064,17 +2072,27 @@ static void ieee80211_sta_work(struct work_struct *work)
         if (ifmgd->flags & (IEEE80211_STA_BEACON_POLL |
                             IEEE80211_STA_CONNECTION_POLL) &&
             ifmgd->associated) {
+                u8 bssid[ETH_ALEN];
+
+                memcpy(bssid, ifmgd->associated->cbss.bssid, ETH_ALEN);
                 if (time_is_after_jiffies(ifmgd->probe_timeout))
                         run_again(ifmgd, ifmgd->probe_timeout);
-                else {
-                        u8 bssid[ETH_ALEN];
+
+                else if (ifmgd->probe_send_count < IEEE80211_MAX_PROBE_TRIES) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+                        printk(KERN_DEBUG "No probe response from AP %pM"
+                                " after %dms, try %d\n", bssid,
+                                (1000 * IEEE80211_PROBE_WAIT)/HZ,
+                                ifmgd->probe_send_count);
+#endif
+                        ieee80211_mgd_probe_ap_send(sdata);
+                } else {
                         /*
                          * We actually lost the connection ... or did we?
                          * Let's make sure!
                          */
                         ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
                                           IEEE80211_STA_BEACON_POLL);
-                        memcpy(bssid, ifmgd->associated->cbss.bssid, ETH_ALEN);
                         printk(KERN_DEBUG "No probe response from AP %pM"
                                 " after %dms, disconnecting.\n",
                                 bssid, (1000 * IEEE80211_PROBE_WAIT)/HZ);