wifi: mt76: mt7996: Add mt7996_mcu_teardown_mld_sta rouine

mt7996_mcu_teardown_mld_sta is used to remove MLO configuration from the
MCU. This is a preliminary patch to enable MLO for MT7996 driver

Co-developed-by: Bo Jiao <Bo.Jiao@mediatek.com>
Signed-off-by: Bo Jiao <Bo.Jiao@mediatek.com>
Co-developed-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250312-b4-mt7996-mlo-p2-v1-3-015b3d6fd928@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>

Author: csyuanc

drivers/net/wireless/mediatek/mt76/mt7996/main.c

@@ -1017,6 +1017,7 @@ mt7996_mac_sta_event(struct mt7996_dev *dev, struct ieee80211_vif *vif,
 		     struct ieee80211_sta *sta, enum mt76_sta_event ev)
 {
 	struct mt7996_sta *msta = (struct mt7996_sta *)sta->drv_priv;
+	unsigned long links = sta->valid_links;
 	struct ieee80211_link_sta *link_sta;
 	unsigned int link_id;
 
@@ -1067,11 +1068,16 @@ mt7996_mac_sta_event(struct mt7996_dev *dev, struct ieee80211_vif *vif,
 				mt7996_mac_twt_teardown_flow(dev, link,
 							     msta_link, i);
 
-			mt7996_mcu_add_sta(dev, link_conf, link_sta, link,
-					   msta_link, CONN_STATE_DISCONNECT,
-					   false);
+			if (sta->mlo && links == BIT(link_id)) /* last link */
+				mt7996_mcu_teardown_mld_sta(dev, link,
+							    msta_link);
+			else
+				mt7996_mcu_add_sta(dev, link_conf, link_sta,
+						   link, msta_link,
+						   CONN_STATE_DISCONNECT, false);
 			msta_link->wcid.sta_disabled = 1;
 			msta_link->wcid.sta = 0;
+			links = links & ~BIT(link_id);
 			break;
 		}
 	}

drivers/net/wireless/mediatek/mt76/mt7996/mcu.c

@@ -2346,6 +2346,24 @@ int mt7996_mcu_add_sta(struct mt7996_dev *dev,
 				     MCU_WMWA_UNI_CMD(STA_REC_UPDATE), true);
 }
 
+int mt7996_mcu_teardown_mld_sta(struct mt7996_dev *dev,
+				struct mt7996_vif_link *link,
+				struct mt7996_sta_link *msta_link)
+{
+	struct sk_buff *skb;
+
+	skb = __mt76_connac_mcu_alloc_sta_req(&dev->mt76, &link->mt76,
+					      &msta_link->wcid,
+					      MT7996_STA_UPDATE_MAX_SIZE);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	mt76_connac_mcu_add_tlv(skb, STA_REC_MLD_OFF, sizeof(struct tlv));
+
+	return mt76_mcu_skb_send_msg(&dev->mt76, skb,
+				     MCU_WMWA_UNI_CMD(STA_REC_UPDATE), true);
+}
+
 static int
 mt7996_mcu_sta_key_tlv(struct mt76_wcid *wcid,
 		       struct sk_buff *skb,

drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h

@@ -578,6 +578,9 @@ int mt7996_mcu_add_sta(struct mt7996_dev *dev,
 		       struct mt7996_vif_link *link,
 		       struct mt7996_sta_link *msta_link,
 		       int conn_state, bool newly);
+int mt7996_mcu_teardown_mld_sta(struct mt7996_dev *dev,
+				struct mt7996_vif_link *link,
+				struct mt7996_sta_link *msta_link);
 int mt7996_mcu_add_tx_ba(struct mt7996_dev *dev,
 			 struct ieee80211_ampdu_params *params,
 			 bool add);