svn commit: r245554 - head/sys/dev/ath

[Adrian Chadd]

Author: adrian
Date: Thu Jan 17 16:26:40 2013
New Revision: 245554
URL: http://svnweb.freebsd.org/changeset/base/245554

Log:
  Add a quick work-around if ath_beacon_config() to not die if it's called
  when an interface is going down.
  
  Right now it's quite possible (but very unlikely!) that ath_reset()
  or similar is called, leading to a beacon config call, in parallel with
  the last VAP being destroyed.
  
  This likely should be fixed by making sure the bmiss/bstuck/watchdog
  taskqueues are canceled whenever the last VAP is destroyed.

Modified:
  head/sys/dev/ath/if_ath_beacon.c

Modified: head/sys/dev/ath/if_ath_beacon.c
==============================================================================
--- head/sys/dev/ath/if_ath_beacon.c	Thu Jan 17 16:11:38 2013	(r245553)
+++ head/sys/dev/ath/if_ath_beacon.c	Thu Jan 17 16:26:40 2013	(r245554)
@@ -705,6 +705,16 @@ ath_beacon_config(struct ath_softc *sc, 
 
 	if (vap == NULL)
 		vap = TAILQ_FIRST(&ic->ic_vaps);	/* XXX */
+	/*
+	 * Just ensure that we aren't being called when the last
+	 * VAP is destroyed.
+	 */
+	if (vap == NULL) {
+		device_printf(sc->sc_dev, "%s: called with no VAPs\n",
+		    __func__);
+		return;
+	}
+
 	ni = ieee80211_ref_node(vap->iv_bss);
 
 	/* extract tstamp from last beacon and convert to TU */