ath9k: Fix RTS/CTS rate selection

The current method of assigning the RTS/CTS rate is completely
broken for HT mode and breaks P2P operation. Fix this by using
the basic_rates provided to the driver by mac80211. For now,
choose the lowest supported basic rate for HT frames.

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/rc.c b/drivers/net/wireless/ath/ath9k/rc.c
index 78192c19fe54767bfa50b71284d104edc901d512..a94c52b24a0b78adab8afcbcae49796f63be3f2c 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/rc.c
+++ b/drivers/net/wireless/ath/ath9k/rc.c
@@ -699,37 +699,25 @@ static void ath_rc_rate_set_rtscts(struct ath_softc *sc,
                                   const struct ath_rate_table *rate_table,
                                   struct ieee80211_tx_info *tx_info)
 {
-       struct ieee80211_tx_rate *rates = tx_info->control.rates;
-       int i = 0, rix = 0, cix, enable_g_protection = 0;
+       struct ieee80211_bss_conf *bss_conf;
 
-       /* get the cix for the lowest valid rix */
-       for (i = 3; i >= 0; i--) {
-               if (rates[i].count && (rates[i].idx >= 0)) {
-                       rix = ath_rc_get_rateindex(rate_table, &rates[i]);
-                       break;
-               }
-       }
-       cix = rate_table->info[rix].ctrl_rate;
+       if (!tx_info->control.vif)
+               return;
+       /*
+        * For legacy frames, mac80211 takes care of CTS protection.
+        */
+       if (!(tx_info->control.rates[0].flags & IEEE80211_TX_RC_MCS))
+               return;
+
+       bss_conf = &tx_info->control.vif->bss_conf;
 
-       /* All protection frames are transmited at 2Mb/s for 802.11g,
-        * otherwise we transmit them at 1Mb/s */
-       if (sc->hw->conf.channel->band == IEEE80211_BAND_2GHZ &&
-           !conf_is_ht(&sc->hw->conf))
-               enable_g_protection = 1;
+       if (!bss_conf->basic_rates)
+               return;
 
        /*
-        * 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.
+        * For now, use the lowest allowed basic rate for HT frames.
         */
-       if ((tx_info->control.vif &&
-            tx_info->control.vif->bss_conf.use_cts_prot) &&
-           (rate_table->info[rix].phy == WLAN_RC_PHY_OFDM ||
-            WLAN_RC_PHY_HT(rate_table->info[rix].phy))) {
-               rates[0].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
-               cix = rate_table->info[enable_g_protection].ctrl_rate;
-       }
-
-       tx_info->control.rts_cts_rate_idx = cix;
+       tx_info->control.rts_cts_rate_idx = __ffs(bss_conf->basic_rates);
 }
 
 static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
@@ -853,7 +841,6 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
                rates[0].count = ATH_TXMAXTRY;
        }
 
-       /* Setup RTS/CTS */
        ath_rc_rate_set_rtscts(sc, rate_table, tx_info);
 }