wifi: rtw89: add EVM and SNR statistics to debugfs

To help debug performance problem, add EVM and SNR statistics to debugfs
that shows

  EVM: [(26.75, 26.75) (25.75, 25.75)]    SNR: 40
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230418012820.5139-5-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/core.c

@@ -1247,13 +1247,16 @@ static void rtw89_core_rx_process_phy_ppdu_iter(void *data,
 	struct rtw89_hal *hal = &rtwdev->hal;
 	u8 ant_num = hal->ant_diversity ? 2 : rtwdev->chip->rf_path_num;
 	u8 ant_pos = U8_MAX;
+	u8 evm_pos = 0;
 	int i;
 
 	if (rtwsta->mac_id != phy_ppdu->mac_id || !phy_ppdu->to_self)
 		return;
 
-	if (hal->ant_diversity && hal->antenna_rx)
+	if (hal->ant_diversity && hal->antenna_rx) {
 		ant_pos = __ffs(hal->antenna_rx);
+		evm_pos = ant_pos;
+	}
 
 	ewma_rssi_add(&rtwsta->avg_rssi, phy_ppdu->rssi_avg);
 
@@ -1263,6 +1266,12 @@ static void rtw89_core_rx_process_phy_ppdu_iter(void *data,
 		for (i = 0; i < rtwdev->chip->rf_path_num; i++)
 			ewma_rssi_add(&rtwsta->rssi[i], phy_ppdu->rssi[i]);
 	}
+
+	if (phy_ppdu->ofdm.has) {
+		ewma_snr_add(&rtwsta->avg_snr, phy_ppdu->ofdm.avg_snr);
+		ewma_evm_add(&rtwsta->evm_min[evm_pos], phy_ppdu->ofdm.evm_min);
+		ewma_evm_add(&rtwsta->evm_max[evm_pos], phy_ppdu->ofdm.evm_max);
+	}
 }
 
 #define VAR_LEN 0xff
@@ -1300,6 +1309,11 @@ static void rtw89_core_parse_phy_status_ie01(struct rtw89_dev *rtwdev, u8 *addr,
 	if (!phy_ppdu->to_self)
 		return;
 
+	phy_ppdu->ofdm.avg_snr = le32_get_bits(ie->w2, RTW89_PHY_STS_IE01_W2_AVG_SNR);
+	phy_ppdu->ofdm.evm_max = le32_get_bits(ie->w2, RTW89_PHY_STS_IE01_W2_EVM_MAX);
+	phy_ppdu->ofdm.evm_min = le32_get_bits(ie->w2, RTW89_PHY_STS_IE01_W2_EVM_MIN);
+	phy_ppdu->ofdm.has = true;
+
 	/* sign conversion for S(12,2) */
 	if (rtwdev->chip->cfo_src_fd) {
 		t = le32_get_bits(ie->w1, RTW89_PHY_STS_IE01_W1_FD_CFO);
@@ -1350,9 +1364,6 @@ static int rtw89_core_rx_process_phy_ppdu(struct rtw89_dev *rtwdev,
 		return -EINVAL;
 	}
 	rtw89_core_update_phy_ppdu(phy_ppdu);
-	ieee80211_iterate_stations_atomic(rtwdev->hw,
-					  rtw89_core_rx_process_phy_ppdu_iter,
-					  phy_ppdu);
 
 	return 0;
 }
@@ -1393,6 +1404,10 @@ static void rtw89_core_rx_process_phy_sts(struct rtw89_dev *rtwdev,
 		rtw89_debug(rtwdev, RTW89_DBG_TXRX, "parse phy sts failed\n");
 	else
 		phy_ppdu->valid = true;
+
+	ieee80211_iterate_stations_atomic(rtwdev->hw,
+					  rtw89_core_rx_process_phy_ppdu_iter,
+					  phy_ppdu);
 }
 
 static u8 rtw89_rxdesc_to_nl_he_gi(struct rtw89_dev *rtwdev,
@@ -2791,8 +2806,12 @@ int rtw89_core_sta_add(struct rtw89_dev *rtwdev,
 		rtw89_core_txq_init(rtwdev, sta->txq[i]);
 
 	ewma_rssi_init(&rtwsta->avg_rssi);
-	for (i = 0; i < ant_num; i++)
+	ewma_snr_init(&rtwsta->avg_snr);
+	for (i = 0; i < ant_num; i++) {
 		ewma_rssi_init(&rtwsta->rssi[i]);
+		ewma_evm_init(&rtwsta->evm_min[i]);
+		ewma_evm_init(&rtwsta->evm_max[i]);
+	}
 
 	if (vif->type == NL80211_IFTYPE_STATION && !sta->tdls) {
 		/* for station mode, assign the mac_id from itself */

drivers/net/wireless/realtek/rtw89/core.h

@@ -551,6 +551,12 @@ struct rtw89_rx_phy_ppdu {
 	u8 chan_idx;
 	u8 ie;
 	u16 rate;
+	struct {
+		bool has;
+		u8 avg_snr;
+		u8 evm_max;
+		u8 evm_min;
+	} ofdm;
 	bool to_self;
 	bool valid;
 };
@@ -2533,6 +2539,8 @@ struct rtw89_ra_report {
 };
 
 DECLARE_EWMA(rssi, 10, 16);
+DECLARE_EWMA(evm, 10, 16);
+DECLARE_EWMA(snr, 10, 16);
 
 struct rtw89_ba_cam_entry {
 	struct list_head list;
@@ -2595,6 +2603,9 @@ struct rtw89_sta {
 	u8 prev_rssi;
 	struct ewma_rssi avg_rssi;
 	struct ewma_rssi rssi[RF_PATH_MAX];
+	struct ewma_snr avg_snr;
+	struct ewma_evm evm_min[RF_PATH_MAX];
+	struct ewma_evm evm_max[RF_PATH_MAX];
 	struct rtw89_ampdu_params ampdu_params[IEEE80211_NUM_TIDS];
 	struct ieee80211_rx_status rx_status;
 	u16 rx_hw_rate;

drivers/net/wireless/realtek/rtw89/debug.c

@@ -3208,7 +3208,9 @@ static void rtw89_sta_info_get_iter(void *data, struct ieee80211_sta *sta)
 	struct rtw89_hal *hal = &rtwdev->hal;
 	u8 ant_num = hal->ant_diversity ? 2 : rtwdev->chip->rf_path_num;
 	bool ant_asterisk = hal->tx_path_diversity || hal->ant_diversity;
+	u8 evm_min, evm_max;
 	u8 rssi;
+	u8 snr;
 	int i;
 
 	seq_printf(m, "TX rate [%d]: ", rtwsta->mac_id);
@@ -3265,6 +3267,20 @@ static void rtw89_sta_info_get_iter(void *data, struct ieee80211_sta *sta)
 			   i + 1 == ant_num ? "" : ", ");
 	}
 	seq_puts(m, "]\n");
+
+	seq_puts(m, "EVM: [");
+	for (i = 0; i < (hal->ant_diversity ? 2 : 1); i++) {
+		evm_min = ewma_evm_read(&rtwsta->evm_min[i]);
+		evm_max = ewma_evm_read(&rtwsta->evm_max[i]);
+
+		seq_printf(m, "%s(%2u.%02u, %2u.%02u)", i == 0 ? "" : " ",
+			   evm_min >> 2, (evm_min & 0x3) * 25,
+			   evm_max >> 2, (evm_max & 0x3) * 25);
+	}
+	seq_puts(m, "]\t");
+
+	snr = ewma_snr_read(&rtwsta->avg_snr);
+	seq_printf(m, "SNR: %u\n", snr);
 }
 
 static void

drivers/net/wireless/realtek/rtw89/txrx.h

@@ -308,6 +308,9 @@ struct rtw89_phy_sts_ie0 {
 #define RTW89_PHY_STS_IE01_W0_CH_IDX GENMASK(23, 16)
 #define RTW89_PHY_STS_IE01_W1_FD_CFO GENMASK(19, 8)
 #define RTW89_PHY_STS_IE01_W1_PREMB_CFO GENMASK(31, 20)
+#define RTW89_PHY_STS_IE01_W2_AVG_SNR GENMASK(5, 0)
+#define RTW89_PHY_STS_IE01_W2_EVM_MAX GENMASK(15, 8)
+#define RTW89_PHY_STS_IE01_W2_EVM_MIN GENMASK(23, 16)
 
 enum rtw89_tx_channel {
 	RTW89_TXCH_ACH0	= 0,