mac80211: run scan after finish connection monitoring

commit 133d40f9a22bdfd2617a446f1e3209537c5415ec
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date:   Wed Mar 28 16:01:19 2012 +0200

    mac80211: do not scan and monitor connection in parallel

add bug, which make possible to start a scan and never finish it, so
make every new scanning request finish with -EBUSY error. This can
happen on code paths where we finish connection monitoring and clear
IEEE80211_STA_*_POLL flags, but do not check if scan was deferred.
This patch fixes those code paths.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 27 insertions, 9 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 04c306308987..d94627c2929c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1220,6 +1220,22 @@ static void ieee80211_sta_wmm_params(struct ieee80211_local *local,
         sdata->vif.bss_conf.qos = true;
 }
 
+static void __ieee80211_stop_poll(struct ieee80211_sub_if_data *sdata)
+{
+        lockdep_assert_held(&sdata->local->mtx);
+
+        sdata->u.mgd.flags &= ~(IEEE80211_STA_CONNECTION_POLL |
+                                IEEE80211_STA_BEACON_POLL);
+        ieee80211_run_deferred_scan(sdata->local);
+}
+
+static void ieee80211_stop_poll(struct ieee80211_sub_if_data *sdata)
+{
+        mutex_lock(&sdata->local->mtx);
+        __ieee80211_stop_poll(sdata);
+        mutex_unlock(&sdata->local->mtx);
+}
+
 static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
                                            u16 capab, bool erp_valid, u8 erp)
 {
@@ -1285,8 +1301,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
         sdata->u.mgd.flags |= IEEE80211_STA_RESET_SIGNAL_AVE;
 
         /* just to be sure */
-        sdata->u.mgd.flags &= ~(IEEE80211_STA_CONNECTION_POLL |
-                                IEEE80211_STA_BEACON_POLL);
+        ieee80211_stop_poll(sdata);
 
         ieee80211_led_assoc(local, 1);
 
@@ -1456,8 +1471,7 @@ static void ieee80211_reset_ap_probe(struct ieee80211_sub_if_data *sdata)
                 return;
         }
 
-        ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
-                          IEEE80211_STA_BEACON_POLL);
+        __ieee80211_stop_poll(sdata);
 
         mutex_lock(&local->iflist_mtx);
         ieee80211_recalc_ps(local, -1);
@@ -1477,7 +1491,6 @@ static void ieee80211_reset_ap_probe(struct ieee80211_sub_if_data *sdata)
                   round_jiffies_up(jiffies +
                                    IEEE80211_CONNECTION_IDLE_TIME));
 out:
-        ieee80211_run_deferred_scan(local);
         mutex_unlock(&local->mtx);
 }
 
@@ -2408,7 +2421,11 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
                 net_dbg_ratelimited("%s: cancelling probereq poll due to a received beacon\n",
                                     sdata->name);
 #endif
+                mutex_lock(&local->mtx);
                 ifmgd->flags &= ~IEEE80211_STA_BEACON_POLL;
+                ieee80211_run_deferred_scan(local);
+                mutex_unlock(&local->mtx);
+
                 mutex_lock(&local->iflist_mtx);
                 ieee80211_recalc_ps(local, -1);
                 mutex_unlock(&local->iflist_mtx);
@@ -2595,8 +2612,7 @@ static void ieee80211_sta_connection_lost(struct ieee80211_sub_if_data *sdata,
         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
         u8 frame_buf[DEAUTH_DISASSOC_LEN];
 
-        ifmgd->flags &= ~(IEEE80211_STA_CONNECTION_POLL |
-                          IEEE80211_STA_BEACON_POLL);
+        ieee80211_stop_poll(sdata);
 
         ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH, reason,
                                false, frame_buf);
@@ -2874,8 +2890,7 @@ static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata)
         u32 flags;
 
         if (sdata->vif.type == NL80211_IFTYPE_STATION) {
-                sdata->u.mgd.flags &= ~(IEEE80211_STA_BEACON_POLL |
-                                        IEEE80211_STA_CONNECTION_POLL);
+                __ieee80211_stop_poll(sdata);
 
                 /* let's probe the connection once */
                 flags = sdata->local->hw.flags;
@@ -2944,7 +2959,10 @@ void ieee80211_sta_restart(struct ieee80211_sub_if_data *sdata)
         if (test_and_clear_bit(TMR_RUNNING_CHANSW, &ifmgd->timers_running))
                 add_timer(&ifmgd->chswitch_timer);
         ieee80211_sta_reset_beacon_monitor(sdata);
+
+        mutex_lock(&sdata->local->mtx);
         ieee80211_restart_sta_timer(sdata);
+        mutex_unlock(&sdata->local->mtx);
 }
 #endif