ath9k: Handle mac80211's RC flags for MCS rates

mac80211 notifies the RC algorithm if RTS/CTS and short preamble
are needed. The RC flags for MCS rates are currently not handled
by mac80211, and ath9k's RC doesn't set the flags either. Fix this.

Also, set the rts_cts_rate_idx inside the RC algorithm.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 40 insertions, 95 deletions

diff --git a/drivers/net/wireless/ath9k/xmit.c b/drivers/net/wireless/ath9k/xmit.c
index d483f3c1350..e14bceaef12 100644
--- a/drivers/net/wireless/ath9k/xmit.c
+++ b/drivers/net/wireless/ath9k/xmit.c
@@ -1386,8 +1386,6 @@ static int setup_tx_flags(struct ath_softc *sc, struct sk_buff *skb,
 
 	if (tx_info->flags & IEEE80211_TX_CTL_NO_ACK)
 		flags |= ATH9K_TXDESC_NOACK;
-	if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
-		flags |= ATH9K_TXDESC_RTSENA;
 
 	return flags;
 }
@@ -1433,137 +1431,86 @@ static u32 ath_pkt_duration(struct ath_softc *sc, u8 rix, struct ath_buf *bf,
 
 static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf)
 {
-	struct ath_hal *ah = sc->sc_ah;
-	struct ath_rate_table *rt;
-	struct ath_desc *ds = bf->bf_desc;
-	struct ath_desc *lastds = bf->bf_lastbf->bf_desc;
+	struct ath_rate_table *rt = sc->cur_rate_table;
 	struct ath9k_11n_rate_series series[4];
 	struct sk_buff *skb;
 	struct ieee80211_tx_info *tx_info;
 	struct ieee80211_tx_rate *rates;
-	struct ieee80211_hdr *hdr;
-	struct ieee80211_hw *hw = sc->hw;
-	int i, flags, rtsctsena = 0, enable_g_protection = 0;
-	u32 ctsduration = 0;
-	u8 rix = 0, cix, ctsrate = 0;
-	__le16 fc;
+	int i, flags = 0;
+	u8 rix = 0, ctsrate = 0;
 
 	memset(series, 0, sizeof(struct ath9k_11n_rate_series) * 4);
 
 	skb = (struct sk_buff *)bf->bf_mpdu;
-	hdr = (struct ieee80211_hdr *)skb->data;
-	fc = hdr->frame_control;
 	tx_info = IEEE80211_SKB_CB(skb);
 	rates = tx_info->control.rates;
 
-	if (ieee80211_has_morefrags(fc) ||
-	    (le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG)) {
-		rates[1].count = rates[2].count = rates[3].count = 0;
-		rates[1].idx = rates[2].idx = rates[3].idx = 0;
-		rates[0].count = ATH_TXMAXTRY;
-	}
-
-	/* get the cix for the lowest valid rix */
-	rt = sc->cur_rate_table;
-	for (i = 3; i >= 0; i--) {
-		if (rates[i].count && (rates[i].idx >= 0)) {
-			rix = rates[i].idx;
-			break;
-		}
-	}
-
-	flags = (bf->bf_flags & (ATH9K_TXDESC_RTSENA | ATH9K_TXDESC_CTSENA));
-	cix = rt->info[rix].ctrl_rate;
-
-	/* All protection frames are transmited at 2Mb/s for 802.11g,
-	 * otherwise we transmit them at 1Mb/s */
-	if (hw->conf.channel->band == IEEE80211_BAND_2GHZ &&
-	  !conf_is_ht(&hw->conf))
-		enable_g_protection = 1;
-
 	/*
-	 * If 802.11g protection is enabled, determine whether to use RTS/CTS or
-	 * just CTS.  Note that this is only done for OFDM/HT unicast frames.
+	 * We check if Short Preamble is needed for the CTS rate by
+	 * checking the BSS's global flag.
+	 * But for the rate series, IEEE80211_TX_RC_USE_SHORT_PREAMBLE is used.
 	 */
-	if (sc->sc_protmode != PROT_M_NONE && !(bf->bf_flags & ATH9K_TXDESC_NOACK)
-	    && (rt->info[rix].phy == WLAN_RC_PHY_OFDM ||
-		WLAN_RC_PHY_HT(rt->info[rix].phy))) {
-		if (sc->sc_protmode == PROT_M_RTSCTS)
-			flags = ATH9K_TXDESC_RTSENA;
-		else if (sc->sc_protmode == PROT_M_CTSONLY)
-			flags = ATH9K_TXDESC_CTSENA;
-
-		cix = rt->info[enable_g_protection].ctrl_rate;
-		rtsctsena = 1;
-	}
+	if (sc->sc_flags & SC_OP_PREAMBLE_SHORT)
+		ctsrate = rt->info[tx_info->control.rts_cts_rate_idx].ratecode |
+			rt->info[tx_info->control.rts_cts_rate_idx].short_preamble;
+	else
+		ctsrate = rt->info[tx_info->control.rts_cts_rate_idx].ratecode;
 
-	/* For 11n, the default behavior is to enable RTS for hw retried frames.
-	 * We enable the global flag here and let rate series flags determine
-	 * which rates will actually use RTS.
+	/*
+	 * ATH9K_TXDESC_RTSENA and ATH9K_TXDESC_CTSENA are mutually exclusive.
+	 * Check the first rate in the series to decide whether RTS/CTS
+	 * or CTS-to-self has to be used.
 	 */
-	if ((ah->ah_caps.hw_caps & ATH9K_HW_CAP_HT) && bf_isdata(bf)) {
-		/* 802.11g protection not needed, use our default behavior */
-		if (!rtsctsena)
-			flags = ATH9K_TXDESC_RTSENA;
-	}
+	if (rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
+		flags = ATH9K_TXDESC_CTSENA;
+	else if (rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
+		flags = ATH9K_TXDESC_RTSENA;
 
-	/* Set protection if aggregate protection on */
+	/* FIXME: Handle aggregation protection */
 	if (sc->sc_config.ath_aggr_prot &&
 	    (!bf_isaggr(bf) || (bf_isaggr(bf) && bf->bf_al < 8192))) {
 		flags = ATH9K_TXDESC_RTSENA;
-		cix = rt->info[enable_g_protection].ctrl_rate;
-		rtsctsena = 1;
 	}
 
 	/* For AR5416 - RTS cannot be followed by a frame larger than 8K */
-	if (bf_isaggr(bf) && (bf->bf_al > ah->ah_caps.rts_aggr_limit))
+	if (bf_isaggr(bf) && (bf->bf_al > sc->sc_ah->ah_caps.rts_aggr_limit))
 		flags &= ~(ATH9K_TXDESC_RTSENA);
 
-	/*
-	 * CTS transmit rate is derived from the transmit rate by looking in the
-	 * h/w rate table.  We must also factor in whether or not a short
-	 * preamble is to be used. NB: cix is set above where RTS/CTS is enabled
-	 */
-	ctsrate = rt->info[cix].ratecode |
-		(bf_isshpreamble(bf) ? rt->info[cix].short_preamble : 0);
-
 	for (i = 0; i < 4; i++) {
 		if (!rates[i].count || (rates[i].idx < 0))
 			continue;
 
 		rix = rates[i].idx;
-
-		series[i].Rate = rt->info[rix].ratecode |
-			(bf_isshpreamble(bf) ? rt->info[rix].short_preamble : 0);
-
 		series[i].Tries = rates[i].count;
+		series[i].ChSel = sc->sc_tx_chainmask;
 
-		series[i].RateFlags = (
-			(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) ?
-				ATH9K_RATESERIES_RTS_CTS : 0) |
-			((rates[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH) ?
-				ATH9K_RATESERIES_2040 : 0) |
-			((rates[i].flags & IEEE80211_TX_RC_SHORT_GI) ?
-				ATH9K_RATESERIES_HALFGI : 0);
+		if (rates[i].flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
+			series[i].Rate = rt->info[rix].ratecode |
+				rt->info[rix].short_preamble;
+		else
+			series[i].Rate = rt->info[rix].ratecode;
+
+		if (rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS)
+			series[i].RateFlags |= ATH9K_RATESERIES_RTS_CTS;
+		if (rates[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
+			series[i].RateFlags |= ATH9K_RATESERIES_2040;
+		if (rates[i].flags & IEEE80211_TX_RC_SHORT_GI)
+			series[i].RateFlags |= ATH9K_RATESERIES_HALFGI;
 
 		series[i].PktDuration = ath_pkt_duration(sc, rix, bf,
 			 (rates[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH) != 0,
 			 (rates[i].flags & IEEE80211_TX_RC_SHORT_GI),
-			 bf_isshpreamble(bf));
-
-		series[i].ChSel = sc->sc_tx_chainmask;
-
-		if (rtsctsena)
-			series[i].RateFlags |= ATH9K_RATESERIES_RTS_CTS;
+			 (rates[i].flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE));
 	}
 
 	/* set dur_update_en for l-sig computation except for PS-Poll frames */
-	ath9k_hw_set11n_ratescenario(ah, ds, lastds, !bf_ispspoll(bf),
-				     ctsrate, ctsduration,
-				     series, 4, flags);
+	ath9k_hw_set11n_ratescenario(sc->sc_ah, bf->bf_desc,
+				     bf->bf_lastbf->bf_desc,
+				     !bf_ispspoll(bf), ctsrate,
+				     0, series, 4, flags);
 
 	if (sc->sc_config.ath_aggr_prot && flags)
-		ath9k_hw_set11n_burstduration(ah, ds, 8192);
+		ath9k_hw_set11n_burstduration(sc->sc_ah, bf->bf_desc, 8192);
 }
 
 static int ath_tx_setup_buffer(struct ath_softc *sc, struct ath_buf *bf,
@@ -1593,8 +1540,6 @@ static int ath_tx_setup_buffer(struct ath_softc *sc, struct ath_buf *bf,
 		bf->bf_state.bf_type |= BUF_BAR;
 	if (ieee80211_is_pspoll(fc))
 		bf->bf_state.bf_type |= BUF_PSPOLL;
-	if (sc->sc_flags & SC_OP_PREAMBLE_SHORT)
-		bf->bf_state.bf_type |= BUF_SHORT_PREAMBLE;
 	if ((conf_is_ht(&sc->hw->conf) && !is_pae(skb) &&
 	     (tx_info->flags & IEEE80211_TX_CTL_AMPDU)))
 		bf->bf_state.bf_type |= BUF_HT;