[PATCH ath-next] wifi: ath12k: fix MLO 4-way handshake timeout on QCC2072

[Miaoqing Pan]

In MLO connections, ath12k_wifi7_dp_rx_set_link_id_wcn7850() attempts
to resolve the IEEE 802.11 link ID for received frames by matching
rxcb->peer_id against the link_peer->peer_id entries in
dp_peer->link_peers[].

This fails for EAPOL frames because the firmware delivers them via
the MLD peer path. In this case, rxcb->peer_id contains an MLD peer
ID while link_peer->peer_id contains a link peer ID. The mismatch
prevents status->link_valid from being set.

When mac80211 receives a data frame with link_valid=0 for an MLO
station, it calls link_sta_info_get_bss() with hdr->addr2 to resolve
the link ID. If hdr->addr2 contains the AP MLD address rather than a
link address, the lookup fails because link_sta_info_get_bss()
indexes by link address, and the frame is dropped in
__ieee80211_rx_handle_packet(). This is observed on QCC2072 where
EAPOL M3 uses the MLD address,

  deauthenticated (Reason: 15=4WAY_HANDSHAKE_TIMEOUT)

Fix this by resolving the link peer using the current operating
frequency associated with each link peer.

For 6 GHz links, the received frequency corresponds to the operating
center frequency, while for other bands it corresponds to the primary
channel frequency. Match the received frame against associated links
using the appropriate frequency for each band.

The frequency-based lookup is used only when exactly one associated
link matches the received frequency. If multiple links share the same
frequency, the match becomes ambiguous and no link ID is assigned. In
that case, leave status->link_valid unset and let mac80211 fall back
to its own link resolution logic.

Tested-on: QCC2072 hw1.0 PCI WLAN.COL.1.0.c2-00228-QCACOLSWPL_V1_TO_SILICON-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3

Fixes: a2fe9dc70f3b ("wifi: ath12k: Fix low MLO RX throughput on WCN7850")
Signed-off-by: Miaoqing Pan <miaoqing.pan at oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath12k/wifi7/dp_rx.c | 55 +++++++++++++++++--
 1 file changed, 49 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/wifi7/dp_rx.c b/drivers/net/wireless/ath/ath12k/wifi7/dp_rx.c
index 95d87dd67872..a3d016d0fb5c 100644
--- a/drivers/net/wireless/ath/ath12k/wifi7/dp_rx.c
+++ b/drivers/net/wireless/ath/ath12k/wifi7/dp_rx.c
@@ -2331,20 +2331,63 @@ ath12k_wifi7_dp_rx_set_link_id_wcn7850(struct ath12k_dp_peer *dp_peer,
 				       struct ath12k_skb_rxcb *rxcb,
 				       struct ieee80211_rx_status *status)
 {
-	struct ath12k_dp_link_peer *link_peer;
+	struct ath12k_dp_link_peer *lp, *link_peer = NULL;
+	struct ieee80211_bss_conf *link_conf;
+	struct ieee80211_chanctx_conf *ctx;
+	struct ieee80211_vif *vif;
+	struct ath12k_sta *ahsta;
 	unsigned long links_map;
+	int freq;
 	int i;
 
 	RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
 			 "ath12k set rx link id called without rcu lock");
 
+	if (!status->freq)
+		return;
+
 	links_map = READ_ONCE(dp_peer->link_peers_map);
 	for_each_set_bit(i, &links_map, ATH12K_NUM_MAX_LINKS) {
-		link_peer = rcu_dereference(dp_peer->link_peers[i]);
-		if (link_peer && link_peer->peer_id == rxcb->peer_id) {
-			status->link_valid = 1;
-			status->link_id = link_peer->link_id;
-			return;
+		lp = rcu_dereference(dp_peer->link_peers[i]);
+		if (!lp || !lp->sta)
+			continue;
+
+		ahsta = ath12k_sta_to_ahsta(lp->sta);
+		if (unlikely(!ahsta->ahvif))
+			continue;
+
+		vif = ahsta->ahvif->vif;
+		link_conf = rcu_dereference(vif->link_conf[lp->link_id]);
+		if (!link_conf)
+			continue;
+
+		ctx = rcu_dereference(link_conf->chanctx_conf);
+		if (!ctx)
+			continue;
+
+		/*
+		 * For 6 GHz, rx_status->freq contains the operating center frequency.
+		 * For other bands, it contains the primary channel frequency.
+		 */
+		freq = status->band == NL80211_BAND_6GHZ ?
+			ctx->def.center_freq1 : ctx->def.chan->center_freq;
+		if (freq != status->freq)
+			continue;
+
+		/*
+		 * Skip freq-based lookup if multiple links share
+		 * the same frequency; the match would be ambiguous.
+		 */
+		if (link_peer) {
+			link_peer = NULL;
+			break;
 		}
+
+		link_peer = lp;
+	}
+
+	if (likely(link_peer)) {
+		status->link_valid = 1;
+		status->link_id = link_peer->link_id;
 	}
 }

base-commit: e07447e654476262558bee570f4cf456e2b32565
-- 
2.34.1