ath9k: Fix RTS threshold

Currently, RTS threshold is not handled for HT. Handle
user-specified threshold values for both aggregated
and unaggregated frames. Use the wiphy's threshold
parameter for now, it can be made per-VIF later on.

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

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index c59ae43..e347d8c 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -999,7 +999,7 @@ void ath_update_max_aggr_framelen(struct ath_softc *sc, int queue, int txop)
 }
 
 static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf,
-                            struct ath_tx_info *info, int len)
+                            struct ath_tx_info *info, int len, bool rts)
 {
        struct ath_hw *ah = sc->sc_ah;
        struct sk_buff *skb;
@@ -1008,6 +1008,7 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf,
        const struct ieee80211_rate *rate;
        struct ieee80211_hdr *hdr;
        struct ath_frame_info *fi = get_frame_info(bf->bf_mpdu);
+       u32 rts_thresh = sc->hw->wiphy->rts_threshold;
        int i;
        u8 rix = 0;
 
@@ -1030,7 +1031,17 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf,
                rix = rates[i].idx;
                info->rates[i].Tries = rates[i].count;
 
-                   if (rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) {
+               /*
+                * Handle RTS threshold for unaggregated HT frames.
+                */
+               if (bf_isampdu(bf) && !bf_isaggr(bf) &&
+                   (rates[i].flags & IEEE80211_TX_RC_MCS) &&
+                   unlikely(rts_thresh != (u32) -1)) {
+                       if (!rts_thresh || (len > rts_thresh))
+                               rts = true;
+               }
+
+               if (rts || rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) {
                        info->rates[i].RateFlags |= ATH9K_RATESERIES_RTS_CTS;
                        info->flags |= ATH9K_TXDESC_RTSENA;
                } else if (rates[i].flags & IEEE80211_TX_RC_USE_CTS_PROTECT) {
@@ -1123,6 +1134,8 @@ static void ath_tx_fill_desc(struct ath_softc *sc, struct ath_buf *bf,
        struct ath_hw *ah = sc->sc_ah;
        struct ath_buf *bf_first = NULL;
        struct ath_tx_info info;
+       u32 rts_thresh = sc->hw->wiphy->rts_threshold;
+       bool rts = false;
 
        memset(&info, 0, sizeof(info));
        info.is_first = true;
@@ -1159,7 +1172,22 @@ static void ath_tx_fill_desc(struct ath_softc *sc, struct ath_buf *bf,
                                info.flags |= (u32) bf->bf_state.bfs_paprd <<
                                              ATH9K_TXDESC_PAPRD_S;
 
-                       ath_buf_set_rate(sc, bf, &info, len);
+                       /*
+                        * mac80211 doesn't handle RTS threshold for HT because
+                        * the decision has to be taken based on AMPDU length
+                        * and aggregation is done entirely inside ath9k.
+                        * Set the RTS/CTS flag for the first subframe based
+                        * on the threshold.
+                        */
+                       if (aggr && (bf == bf_first) &&
+                           unlikely(rts_thresh != (u32) -1)) {
+                               /*
+                                * "len" is the size of the entire AMPDU.
+                                */
+                               if (!rts_thresh || (len > rts_thresh))
+                                       rts = true;
+                       }
+                       ath_buf_set_rate(sc, bf, &info, len, rts);
                }
 
                info.buf_addr[0] = bf->bf_buf_addr;
@@ -2142,7 +2170,7 @@ void ath_tx_cabq(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 
                bf->bf_lastbf = bf;
                ath_set_rates(vif, NULL, bf);
-               ath_buf_set_rate(sc, bf, &info, fi->framelen);
+               ath_buf_set_rate(sc, bf, &info, fi->framelen, false);
                duration += info.rates[0].PktDuration;
                if (bf_tail)
                        bf_tail->bf_next = bf;