mt76: mt7921: fix command timeout in AP stop period

Due to AP stop improperly, mt7921 driver would face random command timeout
by chip fw problem. Migrate AP start/stop process to .start_ap/.stop_ap and
congiure BSS network settings in both hooks.

The new flow is shown below.
* AP start
    .start_ap()
      configure BSS network resource
      set BSS to connected state
    .bss_info_changed()
      enable fw beacon offload

* AP stop
    .bss_info_changed()
      disable fw beacon offload (skip this command)
    .stop_ap()
      set BSS to disconnected state (beacon offload disabled automatically)
      destroy BSS network resource

Fixes: 116c6960 ("mt76: mt7921: Add AP mode support")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c

@@ -1404,6 +1404,8 @@ int mt76_connac_mcu_uni_add_bss(struct mt76_phy *phy,
 		else
 			conn_type = CONNECTION_INFRA_AP;
 		basic_req.basic.conn_type = cpu_to_le32(conn_type);
+		/* Fully active/deactivate BSS network in AP mode only */
+		basic_req.basic.active = enable;
 		break;
 	case NL80211_IFTYPE_STATION:
 		if (vif->p2p)

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

@@ -653,15 +653,6 @@ static void mt7921_bss_info_changed(struct ieee80211_hw *hw,
 		}
 	}
 
-	if (changed & BSS_CHANGED_BEACON_ENABLED && info->enable_beacon) {
-		struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
-
-		mt76_connac_mcu_uni_add_bss(phy->mt76, vif, &mvif->sta.wcid,
-					    true);
-		mt7921_mcu_sta_update(dev, NULL, vif, true,
-				      MT76_STA_INFO_STATE_NONE);
-	}
-
 	if (changed & (BSS_CHANGED_BEACON |
 		       BSS_CHANGED_BEACON_ENABLED))
 		mt7921_mcu_uni_add_beacon_offload(dev, hw, vif,
@@ -1513,6 +1504,44 @@ mt7921_channel_switch_beacon(struct ieee80211_hw *hw,
 	mt7921_mutex_release(dev);
 }
 
+static int
+mt7921_start_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+		unsigned int link_id)
+{
+	struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
+	struct mt7921_phy *phy = mt7921_hw_phy(hw);
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+	int err;
+
+	err = mt76_connac_mcu_uni_add_bss(phy->mt76, vif, &mvif->sta.wcid,
+					  true);
+	if (err)
+		return err;
+
+	err = mt7921_mcu_set_bss_pm(dev, vif, true);
+	if (err)
+		return err;
+
+	return mt7921_mcu_sta_update(dev, NULL, vif, true,
+				     MT76_STA_INFO_STATE_NONE);
+}
+
+static void
+mt7921_stop_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+	       unsigned int link_id)
+{
+	struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
+	struct mt7921_phy *phy = mt7921_hw_phy(hw);
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+	int err;
+
+	err = mt7921_mcu_set_bss_pm(dev, vif, false);
+	if (err)
+		return;
+
+	mt76_connac_mcu_uni_add_bss(phy->mt76, vif, &mvif->sta.wcid, false);
+}
+
 const struct ieee80211_ops mt7921_ops = {
 	.tx = mt7921_tx,
 	.start = mt7921_start,
@@ -1523,6 +1552,8 @@ const struct ieee80211_ops mt7921_ops = {
 	.conf_tx = mt7921_conf_tx,
 	.configure_filter = mt7921_configure_filter,
 	.bss_info_changed = mt7921_bss_info_changed,
+	.start_ap = mt7921_start_ap,
+	.stop_ap = mt7921_stop_ap,
 	.sta_state = mt7921_sta_state,
 	.sta_pre_rcu_remove = mt76_sta_pre_rcu_remove,
 	.set_key = mt7921_set_key,

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

@@ -745,7 +745,7 @@ mt7921_mcu_uni_bss_bcnft(struct mt7921_dev *dev, struct ieee80211_vif *vif,
 				 &bcnft_req, sizeof(bcnft_req), true);
 }
 
-static int
+int
 mt7921_mcu_set_bss_pm(struct mt7921_dev *dev, struct ieee80211_vif *vif,
 		      bool enable)
 {
@@ -774,9 +774,6 @@ mt7921_mcu_set_bss_pm(struct mt7921_dev *dev, struct ieee80211_vif *vif,
 	};
 	int err;
 
-	if (vif->type != NL80211_IFTYPE_STATION)
-		return 0;
-
 	err = mt76_mcu_send_msg(&dev->mt76, MCU_CE_CMD(SET_BSS_ABORT),
 				&req_hdr, sizeof(req_hdr), false);
 	if (err < 0 || !enable)

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

@@ -284,6 +284,8 @@ int mt7921_wpdma_reset(struct mt7921_dev *dev, bool force);
 int mt7921_wpdma_reinit_cond(struct mt7921_dev *dev);
 void mt7921_dma_cleanup(struct mt7921_dev *dev);
 int mt7921_run_firmware(struct mt7921_dev *dev);
+int mt7921_mcu_set_bss_pm(struct mt7921_dev *dev, struct ieee80211_vif *vif,
+			  bool enable);
 int mt7921_mcu_sta_update(struct mt7921_dev *dev, struct ieee80211_sta *sta,
 			  struct ieee80211_vif *vif, bool enable,
 			  enum mt76_sta_info_state state);