mt76: mt7921: properly configure rcpi adding a sta to the fw

Properly configure rcpi based on association process rssi. rcpi is used
by rate controller embedded into the fw to initialize amsdu size.
Tested-by: Jayden.Kuo <jayden.kuo@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7921/mac.c

@@ -9,8 +9,6 @@
 #include "mac.h"
 #include "mcu.h"
 
-#define to_rssi(field, rxv)	((FIELD_GET(field, rxv) - 220) / 2)
-
 #define HE_BITS(f)		cpu_to_le16(IEEE80211_RADIOTAP_HE_##f)
 #define HE_PREP(f, m, v)	le16_encode_bits(le32_get_bits(v, MT_CRXV_HE_##m),\
 						 IEEE80211_RADIOTAP_HE_##f)
@@ -277,6 +275,37 @@ mt7921_get_status_freq_info(struct mt7921_dev *dev, struct mt76_phy *mphy,
 	status->freq = ieee80211_channel_to_frequency(chfreq, status->band);
 }
 
+static void
+mt7921_mac_rssi_iter(void *priv, u8 *mac, struct ieee80211_vif *vif)
+{
+	struct sk_buff *skb = priv;
+	struct mt76_rx_status *status = (struct mt76_rx_status *)skb->cb;
+	struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
+	struct ieee80211_hdr *hdr = mt76_skb_get_hdr(skb);
+
+	if (status->signal > 0)
+		return;
+
+	if (!ether_addr_equal(vif->addr, hdr->addr1))
+		return;
+
+	ewma_rssi_add(&mvif->rssi, -status->signal);
+}
+
+static void
+mt7921_mac_assoc_rssi(struct mt7921_dev *dev, struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr = mt76_skb_get_hdr(skb);
+
+	if (!ieee80211_is_assoc_resp(hdr->frame_control) &&
+	    !ieee80211_is_auth(hdr->frame_control))
+		return;
+
+	ieee80211_iterate_active_interfaces_atomic(mt76_hw(dev),
+		IEEE80211_IFACE_ITER_RESUME_ALL,
+		mt7921_mac_rssi_iter, skb);
+}
+
 int mt7921_mac_fill_rx(struct mt7921_dev *dev, struct sk_buff *skb)
 {
 	struct mt76_rx_status *status = (struct mt76_rx_status *)skb->cb;
@@ -514,6 +543,8 @@ int mt7921_mac_fill_rx(struct mt7921_dev *dev, struct sk_buff *skb)
 		mt76_insert_ccmp_hdr(skb, key_id);
 	}
 
+	mt7921_mac_assoc_rssi(dev, skb);
+
 	if (rxv && status->flag & RX_FLAG_RADIOTAP_HE)
 		mt7921_mac_decode_he_radiotap(skb, status, rxv, mode);
 

drivers/net/wireless/mediatek/mt76/mt7921/main.c

@@ -322,6 +322,8 @@ static int mt7921_add_interface(struct ieee80211_hw *hw,
 	mt7921_mac_wtbl_update(dev, idx,
 			       MT_WTBL_UPDATE_ADM_COUNT_CLEAR);
 
+	ewma_rssi_init(&mvif->rssi);
+
 	rcu_assign_pointer(dev->mt76.wcid[idx], &mvif->sta.wcid);
 	if (vif->txq) {
 		mtxq = (struct mt76_txq *)vif->txq->drv_priv;
@@ -624,12 +626,14 @@ int mt7921_mac_sta_add(struct mt76_dev *mdev, struct ieee80211_vif *vif,
 	struct mt7921_dev *dev = container_of(mdev, struct mt7921_dev, mt76);
 	struct mt7921_sta *msta = (struct mt7921_sta *)sta->drv_priv;
 	struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
+	int rssi = -ewma_rssi_read(&mvif->rssi);
 	struct mt76_sta_cmd_info info = {
 		.sta = sta,
 		.vif = vif,
 		.enable = true,
 		.cmd = MCU_UNI_CMD_STA_REC_UPDATE,
 		.wcid = &msta->wcid,
+		.rcpi = to_rcpi(rssi),
 	};
 	int ret, idx;
 
@@ -686,11 +690,13 @@ void mt7921_mac_sta_remove(struct mt76_dev *mdev, struct ieee80211_vif *vif,
 	mt7921_mac_wtbl_update(dev, msta->wcid.idx,
 			       MT_WTBL_UPDATE_ADM_COUNT_CLEAR);
 
-	if (vif->type == NL80211_IFTYPE_STATION && !sta->tdls) {
+	if (vif->type == NL80211_IFTYPE_STATION) {
 		struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
 
-		mt76_connac_mcu_uni_add_bss(&dev->mphy, vif, &mvif->sta.wcid,
-					    false);
+		ewma_rssi_init(&mvif->rssi);
+		if (!sta->tdls)
+			mt76_connac_mcu_uni_add_bss(&dev->mphy, vif,
+						    &mvif->sta.wcid, false);
 	}
 
 	spin_lock_bh(&dev->sta_poll_lock);

drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h

@@ -46,6 +46,9 @@
 #define MT7921_SKU_MAX_DELTA_IDX	MT7921_SKU_RATE_NUM
 #define MT7921_SKU_TABLE_SIZE		(MT7921_SKU_RATE_NUM + 1)
 
+#define to_rssi(field, rxv)		((FIELD_GET(field, rxv) - 220) / 2)
+#define to_rcpi(rssi)			(2 * (rssi) + 220)
+
 struct mt7921_vif;
 struct mt7921_sta;
 
@@ -92,12 +95,16 @@ struct mt7921_sta {
 	struct mt7921_sta_key_conf bip;
 };
 
+DECLARE_EWMA(rssi, 10, 8);
+
 struct mt7921_vif {
 	struct mt76_vif mt76; /* must be first */
 
 	struct mt7921_sta sta;
 	struct mt7921_phy *phy;
 
+	struct ewma_rssi rssi;
+
 	struct ieee80211_tx_queue_params queue_params[IEEE80211_NUM_ACS];
 };