wifi: mt76: mt7925: fix HT/VHT caps and rates for NAN NDP peers

NAN NDP peers were added with bare link_sta caps: no HT cap or QoS
flag (so no BA/A-MPDU), no VHT cap / bandwidth / rx_nss, a data BSS
phy mode that still read legacy when the firmware built the peer's
rate table, and caps filtered down by the currently committed
schedule.

Push the NAN_DATA BSS phymode before sta_update, force the HT cap and
QoS flag, seed VHT80 / bandwidth / rx_nss=2 from the BSS RLM, fix the
NDP HT/VHT rate selection and stop filtering the link_sta caps by the
schedule, so rate control always sees the peer's real capabilities.

Bench (MT7925<->MT7925 NDP, 5 GHz ch149): 866.7M VHT80 MCS9 NSS2 link
rate, UDP ~290 Mbit/s.

Fixes: 0f3605e4f8de ("wifi: mt76: mt7925: wire up NAN operations")
Co-developed-by: Sean Wang <[email protected]>
Signed-off-by: Sean Wang <[email protected]>
Signed-off-by: Jacobs Wu <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>

mt7925/main.c

@@ -964,6 +964,21 @@ static int mt7925_mac_link_sta_add(struct mt76_dev *mdev,
 
 	link_conf = mt792x_vif_to_bss_conf(vif, link_id);
 
+	/* NAN_DATA (NDI) peers skip association - fill link_sta caps
+	 * from sband and push BSS_INFO with correct phymode + RLM.
+	 */
+	if (vif->type == NL80211_IFTYPE_NAN_DATA) {
+		struct ieee80211_chanctx_conf *nan_ctx;
+
+		nan_ctx = mt7925_nan_seed_link_sta(dev, link_sta);
+		mconf->mt76.ctx = nan_ctx;
+
+		ret = mt7925_mcu_add_bss_info(&dev->phy, nan_ctx,
+					      link_conf, link_sta, true);
+		if (ret)
+			goto out_pm;
+	}
+
 	/* should update bss info before STA add */
 	if (vif->type == NL80211_IFTYPE_STATION && !link_sta->sta->tdls) {
 		struct mt792x_link_sta *mlink_bc;
@@ -2587,8 +2602,8 @@ static int mt7925_start_nan(struct ieee80211_hw *hw,
 	cfg80211_chandef_create(&link_conf->chanreq.oper, chan,
 				NL80211_CHAN_NO_HT);
 
-	err = mt7925_mcu_add_bss_info(&dev->phy, NULL, link_conf,
+	err = mt7925_mcu_add_bss_info(&dev->phy, NULL,
-				      NULL, true);
+				      link_conf, NULL, true);
 	if (err < 0)
 		goto out;
 

mt7925/nan.c

@@ -267,6 +267,68 @@ int mt7925_nan_update_phy_setting(struct mt792x_dev *dev)
 				 &req, sizeof(req), true);
 }
 
+struct ieee80211_chanctx_conf *
+mt7925_nan_seed_link_sta(struct mt792x_dev *dev,
+			 struct ieee80211_link_sta *link_sta)
+{
+	struct ieee80211_supported_band *sband_2g, *sband_5g;
+	struct ieee80211_chanctx_conf *nan_ctx = NULL;
+	struct ieee80211_vif *nan_vif = dev->nan_vif;
+
+	/* Fill HT cap from 2G sband */
+	sband_2g = dev->mphy.hw->wiphy->bands[NL80211_BAND_2GHZ];
+	sband_5g = dev->mphy.hw->wiphy->bands[NL80211_BAND_5GHZ];
+	if (sband_2g)
+		link_sta->ht_cap = sband_2g->ht_cap;
+
+	link_sta->sta->wme = true;
+	link_sta->rx_nss = hweight8(dev->mphy.antenna_mask);
+
+	/* Get chanctx from NAN schedule.
+	 * Prefer 5G committed slot for wider BW (VHT), fallback
+	 * to first valid slot if no 5G data slot is scheduled.
+	 */
+	if (nan_vif) {
+		struct ieee80211_nan_channel **slots =
+			nan_vif->cfg.nan_sched.schedule;
+		int i;
+
+		for (i = 0; i < CFG80211_NAN_SCHED_NUM_TIME_SLOTS; i++) {
+			struct ieee80211_chanctx_conf *ctx;
+
+			if (!slots[i] || IS_ERR(slots[i]) ||
+			    !slots[i]->chanctx_conf)
+				continue;
+
+			ctx = slots[i]->chanctx_conf;
+			if (!nan_ctx)
+				nan_ctx = ctx;
+			if (ctx->def.chan->band == NL80211_BAND_5GHZ) {
+				nan_ctx = ctx;
+				break;
+			}
+		}
+	}
+
+	/* Capability describes what the device can do and must not be
+	 * filtered by the current schedule - firmware gates the VHT rate
+	 * mode per the data schedule and re-derives it on schedule
+	 * change, which only works if the caps are present up front.
+	 */
+	if (sband_5g)
+		link_sta->vht_cap = sband_5g->vht_cap;
+
+	/* Bandwidth here is the capability ceiling, not the operating
+	 * width - the per-slot operating bandwidth follows the current
+	 * slot channel via the firmware RLM sync, so deriving it from
+	 * the schedule at STA-add time would cap a later 5 GHz schedule
+	 * at the bring-up width.
+	 */
+	link_sta->bandwidth = IEEE80211_STA_RX_BW_80;
+
+	return nan_ctx;
+}
+
 int mt7925_nan_enable(struct ieee80211_vif *vif,
 		      struct mt792x_dev *dev,
 		      struct cfg80211_nan_conf *conf)

mt7925/nan.h

@@ -479,6 +479,10 @@ struct mt7925_nan_update_phy_setting_tlv {
 
 int mt7925_nan_update_phy_setting(struct mt792x_dev *dev);
 
+struct ieee80211_chanctx_conf *
+mt7925_nan_seed_link_sta(struct mt792x_dev *dev,
+			 struct ieee80211_link_sta *link_sta);
+
 int mt7925_nan_enable(struct ieee80211_vif *vif,
 		      struct mt792x_dev *dev,
 		      struct cfg80211_nan_conf *conf);