wlan - Disable bgscan by default

* bgscan mode (station scanning while associated) blows up the
  Atheros driver (tested w/ AR9280 chipset).  Turn it off by default.

diff --git a/sys/netproto/802_11/wlan/ieee80211.c b/sys/netproto/802_11/wlan/ieee80211.c
index 9bf79a2..9abf2d8 100644 (file)
--- a/sys/netproto/802_11/wlan/ieee80211.c
+++ b/sys/netproto/802_11/wlan/ieee80211.c
@@ -455,10 +455,18 @@ ieee80211_vap_setup(struct ieee80211com *ic, struct ieee80211vap *vap,
                vap->iv_flags |= IEEE80211_F_WME;
        if (vap->iv_caps & IEEE80211_C_BURST)
                vap->iv_flags |= IEEE80211_F_BURST;
-       /* NB: bg scanning only makes sense for station mode right now */
+#if 0
+       /*
+        * NB: bg scanning only makes sense for station mode right now
+        *
+        * XXX: bgscan is not necessarily stable, so do not enable it by
+        *      default.  It messes up atheros drivers for sure.
+        *      (tested w/ AR9280).
+        */
        if (vap->iv_opmode == IEEE80211_M_STA &&
            (vap->iv_caps & IEEE80211_C_BGSCAN))
                vap->iv_flags |= IEEE80211_F_BGSCAN;
+#endif
        vap->iv_flags |= IEEE80211_F_DOTH;      /* XXX no cap, just ena */
        /* NB: DFS support only makes sense for ap mode right now */
        if (vap->iv_opmode == IEEE80211_M_HOSTAP &&
@@ -573,15 +581,21 @@ ieee80211_vap_detach(struct ieee80211vap *vap)
            __func__, ieee80211_opmode_name[vap->iv_opmode],
            ic->ic_ifp->if_xname);
 
-       /* NB: bpfdetach is called by ether_ifdetach and claims all taps */
+       /*
+        * NB: bpfdetach is called by ether_ifdetach and claims all taps
+        *
+        * ether_ifdetach() must be called without the serializer held.
+        */
+       wlan_assert_serialized();
+       wlan_serialize_exit();  /* exit to block */
        ether_ifdetach(ifp);
 
+       wlan_serialize_enter(); /* then reenter */
        ieee80211_stop(vap);
 
        /*
         * Flush any deferred vap tasks.
         */
-       wlan_assert_serialized();
        wlan_serialize_exit();  /* exit to block */
        ieee80211_draintask(ic, &vap->iv_nstate_task);
        ieee80211_draintask(ic, &vap->iv_swbmiss_task);