ath9k: fix dynack in IBSS mode

Currently, dynack was only tested upstream using AP/STA mode.
Testing it on IBSS, showed that late-ack detection was broken.

This is caused due to dynack using Association Request/Response
frames for late-ack detection, which IBSS does not use.
Also allowing Authentication frames here solves this.

A second issue also got fixed, which was also seen AP/STA mode:

When a station was added, the estimated value would be exponentially averaged
using 0 as a starting point.

This means that on larger distances, the ack timeout was still not high
enough before synchronizing would run out of late-ack's for estimation.

Fix this by using the initial estimated value as a baseline
and only start averaging in the following estimation rounds.

Test setup:
- 2x identical devices:  RB912UAG-5HPnD + 19dB sector
- IBSS
- 2x2 802.11an (ar9340), HT20, long GI
- RSSI's  -70 / -71
- Real distance: 23910 meter

Results (60s iperf runs):

Fixed coverage class 54 (up to 24300m):
* 21.5 Mbits/sec

Dynack:
* 28.9 Mbits/sec

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>

1 files changed, 88 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/ath/554-ath9k-dynack-move-debug-log-after-buffer-increments.patch b/package/kernel/mac80211/patches/ath/554-ath9k-dynack-move-debug-log-after-buffer-increments.patch
new file mode 100644
index 0000000000..a1d612660b
--- /dev/null
+++ b/package/kernel/mac80211/patches/ath/554-ath9k-dynack-move-debug-log-after-buffer-increments.patch
@@ -0,0 +1,88 @@
+From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
+Date: Fri, 2 Nov 2018 21:49:56 +0100
+Subject: [PATCH] ath9k: dynack: move debug log after buffer increments
+
+Move debug log in ath_dynack_sample_tx_ts and ath_dynack_sample_ack_ts
+after timestamp buffer head/tail increments in order to make debugging
+more user friendly
+
+Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
+Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
+---
+
+--- a/drivers/net/wireless/ath/ath9k/dynack.c
++++ b/drivers/net/wireless/ath/ath9k/dynack.c
+@@ -171,11 +171,12 @@ static void ath_dynack_compute_to(struct
+ void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
+ 			     struct ath_tx_status *ts)
+ {
+-	u8 ridx;
+ 	struct ieee80211_hdr *hdr;
+ 	struct ath_dynack *da = &ah->dynack;
+ 	struct ath_common *common = ath9k_hw_common(ah);
+ 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
++	u32 dur = ts->duration;
++	u8 ridx;
+ 
+ 	if ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !da->enabled)
+ 		return;
+@@ -203,14 +204,13 @@ void ath_dynack_sample_tx_ts(struct ath_
+ 	ridx = ts->ts_rateindex;
+ 
+ 	da->st_rbf.ts[da->st_rbf.t_rb].tstamp = ts->ts_tstamp;
+-	da->st_rbf.ts[da->st_rbf.t_rb].dur = ts->duration;
+ 	ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1);
+ 	ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2);
+ 
+ 	if (!(info->status.rates[ridx].flags & IEEE80211_TX_RC_MCS)) {
+-		u32 phy, sifs;
+ 		const struct ieee80211_rate *rate;
+ 		struct ieee80211_tx_rate *rates = info->status.rates;
++		u32 phy;
+ 
+ 		rate = &common->sbands[info->band].bitrates[rates[ridx].idx];
+ 		if (info->band == NL80211_BAND_2GHZ &&
+@@ -219,19 +219,18 @@ void ath_dynack_sample_tx_ts(struct ath_
+ 		else
+ 			phy = WLAN_RC_PHY_OFDM;
+ 
+-		sifs = ath_dynack_get_sifs(ah, phy);
+-		da->st_rbf.ts[da->st_rbf.t_rb].dur -= sifs;
++		dur -= ath_dynack_get_sifs(ah, phy);
+ 	}
+-
+-	ath_dbg(common, DYNACK, "{%pM} tx sample %u [dur %u][h %u-t %u]\n",
+-		hdr->addr1, da->st_rbf.ts[da->st_rbf.t_rb].tstamp,
+-		da->st_rbf.ts[da->st_rbf.t_rb].dur, da->st_rbf.h_rb,
+-		(da->st_rbf.t_rb + 1) % ATH_DYN_BUF);
++	da->st_rbf.ts[da->st_rbf.t_rb].dur = dur;
+ 
+ 	INCR(da->st_rbf.t_rb, ATH_DYN_BUF);
+ 	if (da->st_rbf.t_rb == da->st_rbf.h_rb)
+ 		INCR(da->st_rbf.h_rb, ATH_DYN_BUF);
+ 
++	ath_dbg(common, DYNACK, "{%pM} tx sample %u [dur %u][h %u-t %u]\n",
++		hdr->addr1, ts->ts_tstamp, dur, da->st_rbf.h_rb,
++		da->st_rbf.t_rb);
++
+ 	ath_dynack_compute_to(ah);
+ 
+ 	spin_unlock_bh(&da->qlock);
+@@ -258,14 +257,13 @@ void ath_dynack_sample_ack_ts(struct ath
+ 	spin_lock_bh(&da->qlock);
+ 	da->ack_rbf.tstamp[da->ack_rbf.t_rb] = ts;
+ 
+-	ath_dbg(common, DYNACK, "rx sample %u [h %u-t %u]\n",
+-		da->ack_rbf.tstamp[da->ack_rbf.t_rb],
+-		da->ack_rbf.h_rb, (da->ack_rbf.t_rb + 1) % ATH_DYN_BUF);
+-
+ 	INCR(da->ack_rbf.t_rb, ATH_DYN_BUF);
+ 	if (da->ack_rbf.t_rb == da->ack_rbf.h_rb)
+ 		INCR(da->ack_rbf.h_rb, ATH_DYN_BUF);
+ 
++	ath_dbg(common, DYNACK, "rx sample %u [h %u-t %u]\n",
++		ts, da->ack_rbf.h_rb, da->ack_rbf.t_rb);
++
+ 	ath_dynack_compute_to(ah);
+ 
+ 	spin_unlock_bh(&da->qlock);