From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Wed, 8 Sep 2010 04:40:48 +0000 (-0700)
Subject: wlan - Disable bgscan by default
X-Git-Url: https://gitweb.dragonflybsd.org/~lentferj/dragonfly.git/commitdiff_plain/4584f705ce7f0093fa68de3bec326c8f46f9fb09

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 9bf79a2439..9abf2d8a39 100644
--- 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);