openwrt/package/mac80211/patches/550-ath9k_per_chain_signal_strength.patch

--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -687,6 +687,9 @@ enum mac80211_rx_flags {
  * @mactime: value in microseconds of the 64-bit Time Synchronization Function
  * 	(TSF) timer when the first data symbol (MPDU) arrived at the hardware.
  * @band: the active band when this frame was received
+ * @chains: bitmask of receive chains for which separate signal strength
+ *	values were filled.
+ * @chain_signal: per-chain signal strength, same format as @signal
  * @freq: frequency the radio was tuned to when receiving this frame, in MHz
  * @signal: signal strength when receiving this frame, either in dBm, in dB or
  *	unspecified depending on the hardware capabilities flags
@@ -700,6 +703,10 @@ enum mac80211_rx_flags {
 struct ieee80211_rx_status {
 	u64 mactime;
 	enum ieee80211_band band;
+
+	u8 chains;
+	s8 chain_signal[4];
+
 	int freq;
 	int signal;
 	int antenna;
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -313,6 +313,11 @@ struct sta_info {
 	unsigned long rx_dropped;
 	int last_signal;
 	struct ewma avg_signal;
+
+	u8 chains;
+	s8 chain_signal_last[4];
+	struct ewma chain_signal_avg[4];
+
 	/* Plus 1 for non-QoS frames */
 	__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES + 1];
 
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1271,6 +1271,7 @@ ieee80211_rx_h_sta_process(struct ieee80
 	struct sk_buff *skb = rx->skb;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	int i;
 
 	if (!sta)
 		return RX_CONTINUE;
@@ -1315,6 +1316,19 @@ ieee80211_rx_h_sta_process(struct ieee80
 		ewma_add(&sta->avg_signal, -status->signal);
 	}
 
+	if (status->chains) {
+		sta->chains = status->chains;
+		for (i = 0; i < 4; i++) {
+			int signal = status->chain_signal[i];
+
+			if (!(status->chains & BIT(i)))
+				continue;
+
+			sta->chain_signal_last[i] = signal;
+			ewma_add(&sta->chain_signal_avg[i], -signal);
+		}
+	}
+
 	/*
 	 * Change STA power saving mode only at the end of a frame
 	 * exchange sequence.
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -256,6 +256,8 @@ struct sta_info *sta_info_alloc(struct i
 	do_posix_clock_monotonic_gettime(&uptime);
 	sta->last_connected = uptime.tv_sec;
 	ewma_init(&sta->avg_signal, 1024, 8);
+	for (i = 0; i < ARRAY_SIZE(sta->chain_signal_avg); i++)
+		ewma_init(&sta->chain_signal_avg[i], 1024, 8);
 
 	if (sta_prepare_rate_control(local, sta, gfp)) {
 		kfree(sta);
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -518,6 +518,8 @@ struct station_parameters {
  * @STATION_INFO_ASSOC_REQ_IES: @assoc_req_ies filled
  * @STATION_INFO_STA_FLAGS: @sta_flags filled
  * @STATION_INFO_BEACON_LOSS_COUNT: @beacon_loss_count filled
+ * @STATION_INFO_CHAIN_SIGNAL: @chain_signal filled
+ * @STATION_INFO_CHAIN_SIGNAL_AVG: @chain_signal_avg filled
  */
 enum station_info_flags {
 	STATION_INFO_INACTIVE_TIME	= 1<<0,
@@ -539,7 +541,9 @@ enum station_info_flags {
 	STATION_INFO_CONNECTED_TIME	= 1<<16,
 	STATION_INFO_ASSOC_REQ_IES	= 1<<17,
 	STATION_INFO_STA_FLAGS		= 1<<18,
-	STATION_INFO_BEACON_LOSS_COUNT	= 1<<19
+	STATION_INFO_BEACON_LOSS_COUNT	= 1<<19,
+	STATION_INFO_CHAIN_SIGNAL	= 1<<20,
+	STATION_INFO_CHAIN_SIGNAL_AVG	= 1<<21,
 };
 
 /**
@@ -619,6 +623,9 @@ struct sta_bss_parameters {
  * @plink_state: mesh peer link state
  * @signal: signal strength of last received packet in dBm
  * @signal_avg: signal strength average in dBm
+ * @chains: bitmask for filled values in @chain_signal, @chain_signal_avg
+ * @chain_signal: per-chain signal strength of last received packet in dBm
+ * @chain_signal_avg: per-chain signal strength average in dBm
  * @txrate: current unicast bitrate from this station
  * @rxrate: current unicast bitrate to this station
  * @rx_packets: packets received from this station
@@ -650,6 +657,11 @@ struct station_info {
 	u8 plink_state;
 	s8 signal;
 	s8 signal_avg;
+
+	u8 chains;
+	s8 chain_signal[4];
+	s8 chain_signal_avg[4];
+
 	struct rate_info txrate;
 	struct rate_info rxrate;
 	u32 rx_packets;
--- a/drivers/net/wireless/ath/ath9k/mac.h
+++ b/drivers/net/wireless/ath/ath9k/mac.h
@@ -133,12 +133,8 @@ struct ath_rx_status {
 	u8 rs_rate;
 	u8 rs_antenna;
 	u8 rs_more;
-	int8_t rs_rssi_ctl0;
-	int8_t rs_rssi_ctl1;
-	int8_t rs_rssi_ctl2;
-	int8_t rs_rssi_ext0;
-	int8_t rs_rssi_ext1;
-	int8_t rs_rssi_ext2;
+	int8_t rs_rssi_ctl[3];
+	int8_t rs_rssi_ext[3];
 	u8 rs_isaggr;
 	u8 rs_moreaggr;
 	u8 rs_num_delims;
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -986,6 +986,7 @@ static int ath9k_rx_skb_preprocess(struc
 				   bool *decrypt_error)
 {
 	struct ath_hw *ah = common->ah;
+	int i, j;
 
 	/*
 	 * everything but the rate is checked here, the rate check is done
@@ -1011,6 +1012,20 @@ static int ath9k_rx_skb_preprocess(struc
 	if (rx_stats->rs_moreaggr)
 		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 
+	for (i = 0, j = 0; i < ARRAY_SIZE(rx_stats->rs_rssi_ctl); i++) {
+		s8 rssi;
+
+		if (!(ah->rxchainmask & BIT(i)))
+			continue;
+
+		rssi = rx_stats->rs_rssi_ctl[i];
+		if (rssi != ATH9K_RSSI_BAD) {
+		    rx_status->chains |= BIT(j);
+		    rx_status->chain_signal[j] = ah->noise + rssi;
+		}
+		j++;
+	}
+
 	return 0;
 }
 
@@ -1541,14 +1556,14 @@ static void ath_ant_comb_scan(struct ath
 	struct ath_ant_comb *antcomb = &sc->ant_comb;
 	int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
 	int curr_main_set;
-	int main_rssi = rs->rs_rssi_ctl0;
-	int alt_rssi = rs->rs_rssi_ctl1;
+	int main_rssi = rs->rs_rssi_ctl[0];
+	int alt_rssi = rs->rs_rssi_ctl[1];
 	int rx_ant_conf,  main_ant_conf;
 	bool short_scan = false;
 
-	rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
+	rx_ant_conf = (rs->rs_rssi_ctl[2] >> ATH_ANT_RX_CURRENT_SHIFT) &
 		       ATH_ANT_RX_MASK;
-	main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
+	main_ant_conf = (rs->rs_rssi_ctl[2] >> ATH_ANT_RX_MAIN_SHIFT) &
 			 ATH_ANT_RX_MASK;
 
 	/* Record packet only when both main_rssi and  alt_rssi is positive */
--- a/drivers/net/wireless/ath/ath9k/ar9003_mac.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_mac.c
@@ -453,12 +453,12 @@ int ath9k_hw_process_rxdesc_edma(struct 
 
 	/* XXX: Keycache */
 	rxs->rs_rssi = MS(rxsp->status5, AR_RxRSSICombined);
-	rxs->rs_rssi_ctl0 = MS(rxsp->status1, AR_RxRSSIAnt00);
-	rxs->rs_rssi_ctl1 = MS(rxsp->status1, AR_RxRSSIAnt01);
-	rxs->rs_rssi_ctl2 = MS(rxsp->status1, AR_RxRSSIAnt02);
-	rxs->rs_rssi_ext0 = MS(rxsp->status5, AR_RxRSSIAnt10);
-	rxs->rs_rssi_ext1 = MS(rxsp->status5, AR_RxRSSIAnt11);
-	rxs->rs_rssi_ext2 = MS(rxsp->status5, AR_RxRSSIAnt12);
+	rxs->rs_rssi_ctl[0] = MS(rxsp->status1, AR_RxRSSIAnt00);
+	rxs->rs_rssi_ctl[1] = MS(rxsp->status1, AR_RxRSSIAnt01);
+	rxs->rs_rssi_ctl[2] = MS(rxsp->status1, AR_RxRSSIAnt02);
+	rxs->rs_rssi_ext[0] = MS(rxsp->status5, AR_RxRSSIAnt10);
+	rxs->rs_rssi_ext[1] = MS(rxsp->status5, AR_RxRSSIAnt11);
+	rxs->rs_rssi_ext[2] = MS(rxsp->status5, AR_RxRSSIAnt12);
 
 	if (rxsp->status11 & AR_RxKeyIdxValid)
 		rxs->rs_keyix = MS(rxsp->status11, AR_KeyIdx);
--- a/drivers/net/wireless/ath/ath9k/mac.c
+++ b/drivers/net/wireless/ath/ath9k/mac.c
@@ -556,25 +556,25 @@ int ath9k_hw_rxprocdesc(struct ath_hw *a
 
 	if (ads.ds_rxstatus8 & AR_PostDelimCRCErr) {
 		rs->rs_rssi = ATH9K_RSSI_BAD;
-		rs->rs_rssi_ctl0 = ATH9K_RSSI_BAD;
-		rs->rs_rssi_ctl1 = ATH9K_RSSI_BAD;
-		rs->rs_rssi_ctl2 = ATH9K_RSSI_BAD;
-		rs->rs_rssi_ext0 = ATH9K_RSSI_BAD;
-		rs->rs_rssi_ext1 = ATH9K_RSSI_BAD;
-		rs->rs_rssi_ext2 = ATH9K_RSSI_BAD;
+		rs->rs_rssi_ctl[0] = ATH9K_RSSI_BAD;
+		rs->rs_rssi_ctl[1] = ATH9K_RSSI_BAD;
+		rs->rs_rssi_ctl[2] = ATH9K_RSSI_BAD;
+		rs->rs_rssi_ext[0] = ATH9K_RSSI_BAD;
+		rs->rs_rssi_ext[1] = ATH9K_RSSI_BAD;
+		rs->rs_rssi_ext[2] = ATH9K_RSSI_BAD;
 	} else {
 		rs->rs_rssi = MS(ads.ds_rxstatus4, AR_RxRSSICombined);
-		rs->rs_rssi_ctl0 = MS(ads.ds_rxstatus0,
+		rs->rs_rssi_ctl[0] = MS(ads.ds_rxstatus0,
 						AR_RxRSSIAnt00);
-		rs->rs_rssi_ctl1 = MS(ads.ds_rxstatus0,
+		rs->rs_rssi_ctl[1] = MS(ads.ds_rxstatus0,
 						AR_RxRSSIAnt01);
-		rs->rs_rssi_ctl2 = MS(ads.ds_rxstatus0,
+		rs->rs_rssi_ctl[2] = MS(ads.ds_rxstatus0,
 						AR_RxRSSIAnt02);
-		rs->rs_rssi_ext0 = MS(ads.ds_rxstatus4,
+		rs->rs_rssi_ext[0] = MS(ads.ds_rxstatus4,
 						AR_RxRSSIAnt10);
-		rs->rs_rssi_ext1 = MS(ads.ds_rxstatus4,
+		rs->rs_rssi_ext[1] = MS(ads.ds_rxstatus4,
 						AR_RxRSSIAnt11);
-		rs->rs_rssi_ext2 = MS(ads.ds_rxstatus4,
+		rs->rs_rssi_ext[2] = MS(ads.ds_rxstatus4,
 						AR_RxRSSIAnt12);
 	}
 	if (ads.ds_rxstatus8 & AR_RxKeyIdxValid)
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -993,12 +993,12 @@ void ath_debug_stat_rx(struct ath_softc 
 #ifdef CONFIG_ATH9K_MAC_DEBUG
 	spin_lock(&sc->debug.samp_lock);
 	RX_SAMP_DBG(jiffies) = jiffies;
-	RX_SAMP_DBG(rssi_ctl0) = rs->rs_rssi_ctl0;
-	RX_SAMP_DBG(rssi_ctl1) = rs->rs_rssi_ctl1;
-	RX_SAMP_DBG(rssi_ctl2) = rs->rs_rssi_ctl2;
-	RX_SAMP_DBG(rssi_ext0) = rs->rs_rssi_ext0;
-	RX_SAMP_DBG(rssi_ext1) = rs->rs_rssi_ext1;
-	RX_SAMP_DBG(rssi_ext2) = rs->rs_rssi_ext2;
+	RX_SAMP_DBG(rssi_ctl0) = rs->rs_rssi_ctl[0];
+	RX_SAMP_DBG(rssi_ctl1) = rs->rs_rssi_ctl[1];
+	RX_SAMP_DBG(rssi_ctl2) = rs->rs_rssi_ctl[2];
+	RX_SAMP_DBG(rssi_ext0) = rs->rs_rssi_ext[0];
+	RX_SAMP_DBG(rssi_ext1) = rs->rs_rssi_ext[1];
+	RX_SAMP_DBG(rssi_ext2) = rs->rs_rssi_ext[2];
 	RX_SAMP_DBG(antenna) = rs->rs_antenna;
 	RX_SAMP_DBG(rssi) = rs->rs_rssi;
 	RX_SAMP_DBG(rate) = rs->rs_rate;
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1661,6 +1661,8 @@ enum nl80211_sta_bss_param {
  * @NL80211_STA_INFO_CONNECTED_TIME: time since the station is last connected
  * @NL80211_STA_INFO_STA_FLAGS: Contains a struct nl80211_sta_flag_update.
  * @NL80211_STA_INFO_BEACON_LOSS: count of times beacon loss was detected (u32)
+ * @NL80211_STA_INFO_CHAIN_SIGNAL: per-chain signal strength of last PPDU
+ * @NL80211_STA_INFO_CHAIN_SIGNAL_AVG: per-chain signal strength average
  * @__NL80211_STA_INFO_AFTER_LAST: internal
  * @NL80211_STA_INFO_MAX: highest possible station info attribute
  */
@@ -1684,6 +1686,8 @@ enum nl80211_sta_info {
 	NL80211_STA_INFO_CONNECTED_TIME,
 	NL80211_STA_INFO_STA_FLAGS,
 	NL80211_STA_INFO_BEACON_LOSS,
+	NL80211_STA_INFO_CHAIN_SIGNAL,
+	NL80211_STA_INFO_CHAIN_SIGNAL_AVG,
 
 	/* keep last */
 	__NL80211_STA_INFO_AFTER_LAST,
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2376,6 +2376,33 @@ nla_put_failure:
 	return false;
 }
 
+static bool nl80211_put_signal(struct sk_buff *msg, u8 mask, s8 *signal,
+			       int id)
+{
+	void *attr;
+	int i = 0;
+
+	if (!mask)
+		return true;
+
+	attr = nla_nest_start(msg, id);
+	if (!attr)
+		goto nla_put_failure;
+
+	for (i = 0; i < 4; i++) {
+		if (!(mask & BIT(i)))
+			continue;
+
+		NLA_PUT_U8(msg, i, signal[i]);
+	}
+
+	nla_nest_end(msg, attr);
+
+	return true;
+nla_put_failure:
+	return false;
+}
+
 static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
 				int flags, struct net_device *dev,
 				const u8 *mac_addr, struct station_info *sinfo)
@@ -2422,6 +2449,18 @@ static int nl80211_send_station(struct s
 	if (sinfo->filled & STATION_INFO_SIGNAL_AVG)
 		NLA_PUT_U8(msg, NL80211_STA_INFO_SIGNAL_AVG,
 			   sinfo->signal_avg);
+	if (sinfo->filled & STATION_INFO_CHAIN_SIGNAL) {
+		if (!nl80211_put_signal(msg, sinfo->chains,
+					sinfo->chain_signal,
+					NL80211_STA_INFO_CHAIN_SIGNAL))
+			goto nla_put_failure;
+	}
+	if (sinfo->filled & STATION_INFO_CHAIN_SIGNAL_AVG) {
+		if (!nl80211_put_signal(msg, sinfo->chains,
+					sinfo->chain_signal_avg,
+					NL80211_STA_INFO_CHAIN_SIGNAL_AVG))
+			goto nla_put_failure;
+	}
 	if (sinfo->filled & STATION_INFO_TX_BITRATE) {
 		if (!nl80211_put_sta_rate(msg, &sinfo->txrate,
 					  NL80211_STA_INFO_TX_BITRATE))
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -340,6 +340,7 @@ static void sta_set_sinfo(struct sta_inf
 {
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct timespec uptime;
+	int i;
 
 	sinfo->generation = sdata->local->sta_generation;
 
@@ -377,6 +378,17 @@ static void sta_set_sinfo(struct sta_inf
 		sinfo->signal = (s8)sta->last_signal;
 		sinfo->signal_avg = (s8) -ewma_read(&sta->avg_signal);
 	}
+	if (sta->chains) {
+		sinfo->filled |= STATION_INFO_CHAIN_SIGNAL |
+				 STATION_INFO_CHAIN_SIGNAL_AVG;
+
+		sinfo->chains = sta->chains;
+		for (i = 0; i < ARRAY_SIZE(sinfo->chain_signal); i++) {
+			sinfo->chain_signal[i] = sta->chain_signal_last[i];
+			sinfo->chain_signal_avg[i] =
+				(s8) -ewma_read(&sta->chain_signal_avg[i]);
+		}
+	}
 
 	sinfo->txrate.flags = 0;
 	if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)