mac80211: Add tx ack signal support in sta info

This allows users to get ack signal strength of
last transmitted frame.

Signed-off-by: Venkateswara Naralasetty <vnaralas@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 0c5627f..0bc40c7 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2287,6 +2287,12 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 		sinfo->filled |= BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT);
 		sinfo->expected_throughput = thr;
 	}
+
+	if (!(sinfo->filled & BIT_ULL(NL80211_STA_INFO_ACK_SIGNAL)) &&
+	    sta->status_stats.ack_signal_filled) {
+		sinfo->ack_signal = sta->status_stats.last_ack_signal;
+		sinfo->filled |= BIT_ULL(NL80211_STA_INFO_ACK_SIGNAL);
+	}
 }
 
 u32 sta_get_expected_throughput(struct sta_info *sta)