mac80211: update sta->last_rx on acked tx frames

When clients are idle for too long, hostapd sends nullfunc frames for
probing. When those are acked by the client, the idle time needs to be
updated.

To make this work (and to avoid unnecessary probing), update sta->last_rx
whenever an ACK was received for a tx packet. Only do this if the flag
IEEE80211_HW_REPORTS_TX_ACK_STATUS is set.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/status.c

@@ -180,6 +180,9 @@ static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
 	struct ieee80211_local *local = sta->local;
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 
+	if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
+		sta->last_rx = jiffies;
+
 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
 		struct ieee80211_hdr *hdr = (void *) skb->data;
 		u8 *qc = ieee80211_get_qos_ctl(hdr);