mac80211: fix regression in sta connection monitor

When a frame was acked and probe frames were sent, the connection monitoring
needs to be reset, otherwise it will keep probing until the connection is
considered dead, even though frames have been acked in the mean time.

Fixes: 9abf4e4 ("mac80211: optimize station connection monitor")
Reported-by: Georgi Valkov <gvalkov@abv.bg>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20200927105605.97954-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -2533,7 +2533,9 @@ void ieee80211_sta_tx_notify(struct ieee80211_sub_if_data *sdata,
 	    !sdata->u.mgd.probe_send_count)
 		return;
 
-	if (!ack)
+	if (ack)
+		sdata->u.mgd.probe_send_count = 0;
+	else
 		sdata->u.mgd.nullfunc_failed = true;
 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 }

net/mac80211/status.c

@@ -982,10 +982,6 @@ static void __ieee80211_tx_status(struct ieee80211_hw *hw,
 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
 			ieee80211_frame_acked(sta, skb);
 
-		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
-		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
-			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
-						acked, info->status.tx_time);
 	}
 
 	/* SNMP counters
@@ -1120,11 +1116,18 @@ void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
 
 	if (pubsta) {
+		struct ieee80211_sub_if_data *sdata = sta->sdata;
+
 		if (!acked && !noack_success)
 			sta->status_stats.retry_failed++;
 		sta->status_stats.retry_count += retry_count;
 
 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
+			if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+			    skb && !(info->flags & IEEE80211_TX_CTL_HW_80211_ENCAP))
+				ieee80211_sta_tx_notify(sdata, (void *) skb->data,
+							acked, info->status.tx_time);
+
 			if (acked) {
 				sta->status_stats.last_ack = jiffies;
 
@@ -1134,6 +1137,11 @@ void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
 				/* Track when last packet was ACKed */
 				sta->status_stats.last_pkt_time = jiffies;
 
+				/* Reset connection monitor */
+				if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+				    unlikely(sdata->u.mgd.probe_send_count > 0))
+					sdata->u.mgd.probe_send_count = 0;
+
 				if (info->status.is_valid_ack_signal) {
 					sta->status_stats.last_ack_signal =
 							 (s8)info->status.ack_signal;