iwlwifi: mvm: toggle tx antenna if tx fails during connection establishment

If tx fails during connection establishment, try another antenna for
the next tx. This will increase the chance to establish connection if
one of the antennas is blocked.  Note that the antenna is toggled even
when failing to tx data frames since connection establishment may use
EAPOLs for 802.1X authentication/ 4 way handshake.
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/sta.c

@@ -1768,6 +1768,8 @@ int iwl_mvm_add_sta(struct iwl_mvm *mvm,
 	if (iwl_mvm_has_tlc_offload(mvm))
 		iwl_mvm_rs_add_sta(mvm, mvm_sta);
 
+	iwl_mvm_toggle_tx_ant(mvm, &mvm_sta->tx_ant);
+
 update_fw:
 	ret = iwl_mvm_sta_send_to_fw(mvm, sta, sta_update, sta_flags);
 	if (ret)

drivers/net/wireless/intel/iwlwifi/mvm/sta.h

@@ -397,6 +397,9 @@ struct iwl_mvm_rxq_dup_data {
  * @ptk_pn: per-queue PTK PN data structures
  * @dup_data: per queue duplicate packet detection data
  * @deferred_traffic_tid_map: indication bitmap of deferred traffic per-TID
+ * @tx_ant: the index of the antenna to use for data tx to this station. Only
+ *	used during connection establishment (e.g. for the 4 way handshake
+ *	exchange).
  *
  * When mac80211 creates a station it reserves some space (hw->sta_data_size)
  * in the structure for use by driver. This structure is placed in that
@@ -439,6 +442,7 @@ struct iwl_mvm_sta {
 	u8 agg_tids;
 	u8 sleep_tx_count;
 	u8 avg_energy;
+	u8 tx_ant;
 };
 
 u16 iwl_mvm_tid_queued(struct iwl_mvm *mvm, struct iwl_mvm_tid_data *tid_data);

drivers/net/wireless/intel/iwlwifi/mvm/tx.c

@@ -302,13 +302,30 @@ void iwl_mvm_set_tx_cmd(struct iwl_mvm *mvm, struct sk_buff *skb,
 					    offload_assist));
 }
 
+static u32 iwl_mvm_get_tx_ant(struct iwl_mvm *mvm,
+			      struct ieee80211_tx_info *info,
+			      struct ieee80211_sta *sta, __le16 fc)
+{
+	if (info->band == NL80211_BAND_2GHZ &&
+	    !iwl_mvm_bt_coex_is_shared_ant_avail(mvm))
+		return mvm->cfg->non_shared_ant << RATE_MCS_ANT_POS;
+
+	if (sta && ieee80211_is_data(fc)) {
+		struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
+
+		return BIT(mvmsta->tx_ant) << RATE_MCS_ANT_POS;
+	}
+
+	return BIT(mvm->mgmt_last_antenna_idx) << RATE_MCS_ANT_POS;
+}
+
 static u32 iwl_mvm_get_tx_rate(struct iwl_mvm *mvm,
 			       struct ieee80211_tx_info *info,
 			       struct ieee80211_sta *sta)
 {
 	int rate_idx;
 	u8 rate_plcp;
-	u32 rate_flags;
+	u32 rate_flags = 0;
 
 	/* HT rate doesn't make sense for a non data frame */
 	WARN_ONCE(info->control.rates[0].flags & IEEE80211_TX_RC_MCS,
@@ -332,13 +349,6 @@ static u32 iwl_mvm_get_tx_rate(struct iwl_mvm *mvm,
 	/* Get PLCP rate for tx_cmd->rate_n_flags */
 	rate_plcp = iwl_mvm_mac80211_idx_to_hwrate(rate_idx);
 
-	if (info->band == NL80211_BAND_2GHZ &&
-	    !iwl_mvm_bt_coex_is_shared_ant_avail(mvm))
-		rate_flags = mvm->cfg->non_shared_ant << RATE_MCS_ANT_POS;
-	else
-		rate_flags =
-			BIT(mvm->mgmt_last_antenna_idx) << RATE_MCS_ANT_POS;
-
 	/* Set CCK flag as needed */
 	if ((rate_idx >= IWL_FIRST_CCK_RATE) && (rate_idx <= IWL_LAST_CCK_RATE))
 		rate_flags |= RATE_MCS_CCK_MSK;
@@ -346,6 +356,14 @@ static u32 iwl_mvm_get_tx_rate(struct iwl_mvm *mvm,
 	return (u32)rate_plcp | rate_flags;
 }
 
+static u32 iwl_mvm_get_tx_rate_n_flags(struct iwl_mvm *mvm,
+				       struct ieee80211_tx_info *info,
+				       struct ieee80211_sta *sta, __le16 fc)
+{
+	return iwl_mvm_get_tx_rate(mvm, info, sta) |
+		iwl_mvm_get_tx_ant(mvm, info, sta, fc);
+}
+
 /*
  * Sets the fields in the Tx cmd that are rate related
  */
@@ -373,16 +391,21 @@ void iwl_mvm_set_tx_cmd_rate(struct iwl_mvm *mvm, struct iwl_tx_cmd *tx_cmd,
 	 */
 
 	if (ieee80211_is_data(fc) && sta) {
-		tx_cmd->initial_rate_index = 0;
-		tx_cmd->tx_flags |= cpu_to_le32(TX_CMD_FLG_STA_RATE);
-		return;
+		struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
+
+		if (mvmsta->sta_state >= IEEE80211_STA_AUTHORIZED) {
+			tx_cmd->initial_rate_index = 0;
+			tx_cmd->tx_flags |= cpu_to_le32(TX_CMD_FLG_STA_RATE);
+			return;
+		}
 	} else if (ieee80211_is_back_req(fc)) {
 		tx_cmd->tx_flags |=
 			cpu_to_le32(TX_CMD_FLG_ACK | TX_CMD_FLG_BAR);
 	}
 
 	/* Set the rate in the TX cmd */
-	tx_cmd->rate_n_flags = cpu_to_le32(iwl_mvm_get_tx_rate(mvm, info, sta));
+	tx_cmd->rate_n_flags =
+		cpu_to_le32(iwl_mvm_get_tx_rate_n_flags(mvm, info, sta, fc));
 }
 
 static inline void iwl_mvm_set_tx_cmd_pn(struct ieee80211_tx_info *info,
@@ -487,6 +510,8 @@ iwl_mvm_set_tx_params(struct iwl_mvm *mvm, struct sk_buff *skb,
 		u16 offload_assist = 0;
 		u32 rate_n_flags = 0;
 		u16 flags = 0;
+		struct iwl_mvm_sta *mvmsta = sta ?
+			iwl_mvm_sta_from_mac80211(sta) : NULL;
 
 		if (ieee80211_is_data_qos(hdr->frame_control)) {
 			u8 *qc = ieee80211_get_qos_ctl(hdr);
@@ -506,10 +531,16 @@ iwl_mvm_set_tx_params(struct iwl_mvm *mvm, struct sk_buff *skb,
 		if (!info->control.hw_key)
 			flags |= IWL_TX_FLAGS_ENCRYPT_DIS;
 
-		/* For data packets rate info comes from the fw */
-		if (!(ieee80211_is_data(hdr->frame_control) && sta)) {
+		/*
+		 * For data packets rate info comes from the fw. Only
+		 * set rate/antenna during connection establishment.
+		 */
+		if (sta && (!ieee80211_is_data(hdr->frame_control) ||
+			    mvmsta->sta_state < IEEE80211_STA_AUTHORIZED)) {
 			flags |= IWL_TX_FLAGS_CMD_RATE;
-			rate_n_flags = iwl_mvm_get_tx_rate(mvm, info, sta);
+			rate_n_flags =
+				iwl_mvm_get_tx_rate_n_flags(mvm, info, sta,
+							    hdr->frame_control);
 		}
 
 		if (mvm->trans->cfg->device_family >=
@@ -1600,6 +1631,10 @@ static void iwl_mvm_rx_tx_cmd_single(struct iwl_mvm *mvm,
 		iwl_mvm_tx_airtime(mvm, mvmsta,
 				   le16_to_cpu(tx_resp->wireless_media_time));
 
+		if ((status & TX_STATUS_MSK) != TX_STATUS_SUCCESS &&
+		    mvmsta->sta_state < IEEE80211_STA_AUTHORIZED)
+			iwl_mvm_toggle_tx_ant(mvm, &mvmsta->tx_ant);
+
 		if (sta->wme && tid != IWL_MGMT_TID) {
 			struct iwl_mvm_tid_data *tid_data =
 				&mvmsta->tid_data[tid];