From cc60dbbfed8ff0bd4c530ee48e9e915333a35470 Mon Sep 17 00:00:00 2001
From: Balaji Pothunoori <bpothuno@codeaurora.org>
Date: Mon, 16 Apr 2018 20:18:41 +0530
Subject: [PATCH] mac80211: average ack rssi support for data frames
Git-commit: cc60dbbfed8ff0bd4c530ee48e9e915333a35470
Patch-mainline: v4.18-rc1
References: FATE#326294

The driver will process the RSSI if available and send it to mac80211.
mac80211 will compute the weighted average of ack RSSI for stations.

Signed-off-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/mac80211/sta_info.c | 10 ++++++++++
 net/mac80211/sta_info.h |  2 ++
 net/mac80211/status.c   |  2 ++
 3 files changed, 14 insertions(+)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 2d5ffb0a16f6..f83e6e2ad5ab 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -358,6 +358,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 
 	sta->last_connected = ktime_get_seconds();
 	ewma_signal_init(&sta->rx_stats_avg.signal);
+	ewma_avg_signal_init(&sta->status_stats.avg_ack_signal);
 	for (i = 0; i < ARRAY_SIZE(sta->rx_stats_avg.chain_signal); i++)
 		ewma_signal_init(&sta->rx_stats_avg.chain_signal[i]);
 
@@ -2294,6 +2295,15 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 		sinfo->ack_signal = sta->status_stats.last_ack_signal;
 		sinfo->filled |= BIT_ULL(NL80211_STA_INFO_ACK_SIGNAL);
 	}
+
+	if (ieee80211_hw_check(&sta->local->hw, REPORTS_TX_ACK_STATUS) &&
+	    !(sinfo->filled & BIT_ULL(NL80211_STA_INFO_DATA_ACK_SIGNAL_AVG))) {
+		sinfo->avg_ack_signal =
+			-(s8)ewma_avg_signal_read(
+				&sta->status_stats.avg_ack_signal);
+		sinfo->filled |=
+			BIT_ULL(NL80211_STA_INFO_DATA_ACK_SIGNAL_AVG);
+	}
 }
 
 u32 sta_get_expected_throughput(struct sta_info *sta)
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index f64eb86ca64b..d79bd6eeb549 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -119,6 +119,7 @@ enum ieee80211_sta_info_flags {
 #define HT_AGG_STATE_START_CB		6
 #define HT_AGG_STATE_STOP_CB		7
 
+DECLARE_EWMA(avg_signal, 10, 8)
 enum ieee80211_agg_stop_reason {
 	AGG_STOP_DECLINED,
 	AGG_STOP_LOCAL_REQUEST,
@@ -550,6 +551,7 @@ struct sta_info {
 		unsigned long last_ack;
 		s8 last_ack_signal;
 		bool ack_signal_filled;
+		struct ewma_avg_signal avg_ack_signal;
 	} status_stats;
 
 	/* Updated from TX path only, no locking requirements */
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 743e89c5926c..9a6d7208bf4f 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -195,6 +195,8 @@ static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
 			sta->status_stats.last_ack_signal =
 					 (s8)txinfo->status.ack_signal;
 			sta->status_stats.ack_signal_filled = true;
+			ewma_avg_signal_add(&sta->status_stats.avg_ack_signal,
+					    -txinfo->status.ack_signal);
 		}
 	}
 
-- 
2.19.2