nuke special handling to extend cts when bursting; it was race prone

MFC after:	7 days

3 files changed, 2 insertions, 65 deletions

diff --git a/sys/dev/ath/if_ath.c b/sys/dev/ath/if_ath.c
index 0b54516..6e92a05 100644
--- a/sys/dev/ath/if_ath.c
+++ b/sys/dev/ath/if_ath.c
@@ -3114,13 +3114,6 @@ static int
 ath_tx_start(struct ath_softc *sc, struct ieee80211_node *ni, struct ath_buf *bf,
     struct mbuf *m0)
 {
-#define	CTS_DURATION \
-	ath_hal_computetxtime(ah, rt, IEEE80211_ACK_LEN, cix, AH_TRUE)
-#define	updateCTSForBursting(_ah, _ds, _txq) \
-	ath_hal_updateCTSForBursting(_ah, _ds, \
-	    _txq->axq_linkbuf != NULL ? _txq->axq_linkbuf->bf_desc : NULL, \
-	    _txq->axq_lastdsWithCTS, _txq->axq_gatingds, \
-	    txopLimit, CTS_DURATION)
 	struct ieee80211com *ic = &sc->sc_ic;
 	struct ath_hal *ah = sc->sc_ah;
 	struct ifnet *ifp = sc->sc_ifp;
@@ -3535,39 +3528,6 @@ ath_tx_start(struct ath_softc *sc, struct ieee80211_node *ni, struct ath_buf *bf
 	 * pass it on to the hardware.
 	 */
 	ATH_TXQ_LOCK(txq);
-	if (flags & (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA)) {
-		u_int32_t txopLimit = IEEE80211_TXOP_TO_US(
-			cap->cap_wmeParams[pri].wmep_txopLimit);
-		/*
-		 * When bursting, potentially extend the CTS duration
-		 * of a previously queued frame to cover this frame
-		 * and not exceed the txopLimit.  If that can be done
-		 * then disable RTS/CTS on this frame since it's now
-		 * covered (burst extension).  Otherwise we must terminate
-		 * the burst before this frame goes out so as not to
-		 * violate the WME parameters.  All this is complicated
-		 * as we need to update the state of packets on the
-		 * (live) hardware queue.  The logic is buried in the hal
-		 * because it's highly chip-specific.
-		 */
-		if (txopLimit != 0) {
-			sc->sc_stats.ast_tx_ctsburst++;
-			if (updateCTSForBursting(ah, ds0, txq) == 0) {
-				/*
-				 * This frame was not covered by RTS/CTS from
-				 * the previous frame in the burst; update the
-				 * descriptor pointers so this frame is now
-				 * treated as the last frame for extending a
-				 * burst.
-				 */
-				txq->axq_lastdsWithCTS = ds0;
-				/* set gating Desc to final desc */
-				txq->axq_gatingds =
-					(struct ath_desc *)txq->axq_link;
-			} else
-				sc->sc_stats.ast_tx_ctsext++;
-		}
-	}
 	ATH_TXQ_INSERT_TAIL(txq, bf, bf_list);
 	if (txq->axq_link == NULL) {
 		ath_hal_puttxbuf(ah, txq->axq_qnum, bf->bf_daddr);
@@ -3592,8 +3552,6 @@ ath_tx_start(struct ath_softc *sc, struct ieee80211_node *ni, struct ath_buf *bf
 	ATH_TXQ_UNLOCK(txq);
 
 	return 0;
-#undef updateCTSForBursting
-#undef CTS_DURATION
 }
 
 /*
@@ -3635,10 +3593,6 @@ ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
 			ATH_TXQ_UNLOCK(txq);
 			break;
 		}
-		if (ds0 == txq->axq_lastdsWithCTS)
-			txq->axq_lastdsWithCTS = NULL;
-		if (ds == txq->axq_gatingds)
-			txq->axq_gatingds = NULL;
 		ATH_TXQ_REMOVE_HEAD(txq, bf_list);
 		ATH_TXQ_UNLOCK(txq);
 
diff --git a/sys/dev/ath/if_athioctl.h b/sys/dev/ath/if_athioctl.h
index 3e7ec73..7eb2cea 100644
--- a/sys/dev/ath/if_athioctl.h
+++ b/sys/dev/ath/if_athioctl.h
@@ -75,8 +75,8 @@ struct ath_stats {
 	u_int32_t	ast_tx_shortpre;/* tx frames with short preamble */
 	u_int32_t	ast_tx_altrate;	/* tx frames with alternate rate */
 	u_int32_t	ast_tx_protect;	/* tx frames with protection */
-	u_int32_t	ast_tx_ctsburst;/* tx frames with cts and bursting */
-	u_int32_t	ast_tx_ctsext;	/* tx frames with cts extension */
+	u_int32_t	ast_unused1;
+	u_int32_t	ast_unused2;
 	u_int32_t	ast_rx_nombuf;	/* rx setup failed 'cuz no mbuf */
 	u_int32_t	ast_rx_busdma;	/* rx setup failed for dma resrcs */
 	u_int32_t	ast_rx_orn;	/* rx failed 'cuz of desc overrun */
diff --git a/sys/dev/ath/if_athvar.h b/sys/dev/ath/if_athvar.h
index 21c319e..f628645 100644
--- a/sys/dev/ath/if_athvar.h
+++ b/sys/dev/ath/if_athvar.h
@@ -140,19 +140,6 @@ struct ath_txq {
 	u_int32_t		*axq_link;	/* link ptr in last TX desc */
 	STAILQ_HEAD(, ath_buf)	axq_q;		/* transmit queue */
 	struct mtx		axq_lock;	/* lock on q and link */
-	/*
-	 * State for patching up CTS when bursting.
-	 */
-	struct	ath_buf		*axq_linkbuf;	/* va of last buffer */
-	struct	ath_desc	*axq_lastdsWithCTS;
-						/* first desc of last descriptor
-						 * that contains CTS 
-						 */
-	struct	ath_desc	*axq_gatingds;	/* final desc of the gating desc
-						 * that determines whether
-						 * lastdsWithCTS has been DMA'ed
-						 * or not
-						 */
 };
 
 #define	ATH_TXQ_LOCK_INIT(_sc, _tq) \
@@ -512,10 +499,6 @@ void	ath_intr(void *);
 	((*(_ah)->ah_fillTxDesc)((_ah), (_ds), (_l), (_first), (_last), (_ds0)))
 #define	ath_hal_txprocdesc(_ah, _ds) \
 	((*(_ah)->ah_procTxDesc)((_ah), (_ds)))
-#define	ath_hal_updateCTSForBursting(_ah, _ds, _prevds, _prevdsWithCTS, \
-		_gatingds,  _txOpLimit, _ctsDuration) \
-	((*(_ah)->ah_updateCTSForBursting)((_ah), (_ds), (_prevds), \
-		(_prevdsWithCTS), (_gatingds), (_txOpLimit), (_ctsDuration)))
 
 #define ath_hal_gpioCfgOutput(_ah, _gpio) \
         ((*(_ah)->ah_gpioCfgOutput)((_ah), (_gpio)))