svn commit: r225822 - head/sys/dev/ath

[Adrian Chadd]

Author: adrian
Date: Wed Sep 28 03:11:51 2011
New Revision: 225822
URL: http://svn.freebsd.org/changeset/base/225822

Log:
  Don't bother triggering the cabq queue if it's empty.
  
  Obtained from:	Atheros

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

Modified: head/sys/dev/ath/if_ath.c
==============================================================================
--- head/sys/dev/ath/if_ath.c	Wed Sep 28 03:07:51 2011	(r225821)
+++ head/sys/dev/ath/if_ath.c	Wed Sep 28 03:11:51 2011	(r225822)
@@ -2619,7 +2619,8 @@ ath_beacon_generate(struct ath_softc *sc
 			sc->sc_stats.ast_cabq_xmit += nmcastq;
 		}
 		/* NB: gated by beacon so safe to start here */
-		ath_hal_txstart(ah, cabq->axq_qnum);
+		if (! STAILQ_EMPTY(&(cabq->axq_q)))
+			ath_hal_txstart(ah, cabq->axq_qnum);
 		ATH_TXQ_UNLOCK(&avp->av_mcastq);
 		ATH_TXQ_UNLOCK(cabq);
 	}