[PATCH 5/5] wifi: ath12k: skip connection_loss_work for MLO beacon miss

[Jose Ignacio Tornos Martinez <jtornosm@redhat.com>]

When firmware reports a beacon miss, ath12k queues connection_loss_work
as a 3-second backup timer that forces a full VIF disconnect via
ieee80211_connection_loss(). This work can only be cancelled when a
beacon frame arrives through WMI in ath12k_mac_handle_beacon_iter().

In MLO, this mechanism causes periodic spurious disconnections because
the firmware does not reliably forward beacon frames to the host via
WMI, making the cancellation path ineffective. The result is a full
VIF disconnect every ~16 seconds during normal MLO operation, easily
reproducible under heavy traffic.

Skip queueing connection_loss_work for MLO VIFs. The mac80211 AP probe
triggered by ieee80211_beacon_loss() is sufficient to detect real AP
unreachability. Other MLO-capable drivers such as mt76 and rtw89
similarly rely on ieee80211_beacon_loss() without adding a backup
disconnect timer.

Tested on WCN7850 with MLO (Wi-Fi 7).

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
---
 drivers/net/wireless/ath/ath12k/mac.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index af09153ad9d9..dfd69822c5ce 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -2008,9 +2008,16 @@ void ath12k_mac_handle_beacon_miss(struct ath12k *ar,
 	 * (done by mac80211) succeeds but beacons do not resume then it
 	 * doesn't make sense to continue operation. Queue connection loss work
 	 * which can be cancelled when beacon is received.
+	 *
+	 * Skip for MLO because connection_loss_work disconnects the entire
+	 * VIF based on a single link's beacon miss, and its cancellation
+	 * mechanism (beacon reception via WMI) is unreliable. The mac80211
+	 * probe triggered by ieee80211_beacon_loss() above is sufficient
+	 * to detect real AP unreachability.
 	 */
-	ieee80211_queue_delayed_work(hw, &arvif->connection_loss_work,
-				     ATH12K_CONNECTION_LOSS_HZ);
+	if (!ieee80211_vif_is_mld(vif))
+		ieee80211_queue_delayed_work(hw, &arvif->connection_loss_work,
+					     ATH12K_CONNECTION_LOSS_HZ);
 }
 
 static void ath12k_mac_vif_sta_connection_loss_work(struct work_struct *work)
-- 
2.54.0