[PATCH 0/5] fix ath9k dynack in ad-hoc mode

[PATCH 0/5] fix ath9k dynack in ad-hoc mode

[Lorenzo Bianconi]

Add properly support for dynack in ibss mode. Moreover
allow acktimeout ewma estimation to converge faster
to the correct value during 'late ack' phase.
This series has been tested on devices mounted on offshore
high-voltage stations connected through ~24Km link

Lorenzo Bianconi (5):
  ath9k: dynack: use authentication messages for 'late' ack
  ath9k: dynack: move debug log after buffer increments
  ath9k: dynack: check da->enabled first in sampling routines
  ath9k: dynack: make ewma estimation faster
  ath9k: dynack: remove 'experimental' tag

 drivers/net/wireless/ath/ath9k/Kconfig  |  2 +-
 drivers/net/wireless/ath/ath9k/ath9k.h  |  2 +-
 drivers/net/wireless/ath/ath9k/dynack.c | 61 +++++++++++++++----------
 drivers/net/wireless/ath/ath9k/dynack.h |  6 ++-
 drivers/net/wireless/ath/ath9k/xmit.c   |  5 +-
 5 files changed, 46 insertions(+), 30 deletions(-)

-- 
2.19.1

[PATCH 1/5] ath9k: dynack: use authentication messages for 'late' ack

[Lorenzo Bianconi]

In order to properly support dynack in ad-hoc mode running
wpa_supplicant, take into account authentication frames for
'late ack' detection. This patch has been tested on devices
mounted on offshore high-voltage stations connected through
~24Km link

Reported-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 drivers/net/wireless/ath/ath9k/dynack.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c
index 7334c9b09e82..cc0dc966c512 100644
--- a/drivers/net/wireless/ath/ath9k/dynack.c
+++ b/drivers/net/wireless/ath/ath9k/dynack.c
@@ -187,7 +187,8 @@ void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
 	/* late ACK */
 	if (ts->ts_status & ATH9K_TXERR_XRETRY) {
 		if (ieee80211_is_assoc_req(hdr->frame_control) ||
-		    ieee80211_is_assoc_resp(hdr->frame_control)) {
+		    ieee80211_is_assoc_resp(hdr->frame_control) ||
+		    ieee80211_is_auth(hdr->frame_control)) {
 			ath_dbg(common, DYNACK, "late ack\n");
 			ath9k_hw_setslottime(ah, (LATEACK_TO - 3) / 2);
 			ath9k_hw_set_ack_timeout(ah, LATEACK_TO);
-- 
2.19.1

Re: [PATCH 1/5] ath9k: dynack: use authentication messages for 'late' ack

[Kalle Valo]

Lorenzo Bianconi <lorenzo.bianconi@redhat.com> wrote:

> In order to properly support dynack in ad-hoc mode running
> wpa_supplicant, take into account authentication frames for
> 'late ack' detection. This patch has been tested on devices
> mounted on offshore high-voltage stations connected through
> ~24Km link
> 
> Reported-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
> Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

5 patches applied to ath-next branch of ath.git, thanks.

3831a2a0010c ath9k: dynack: use authentication messages for 'late' ack
5e3d4718b157 ath9k: dynack: move debug log after buffer increments
9d3d65a91f02 ath9k: dynack: check da->enabled first in sampling routines
0c60c490830a ath9k: dynack: make ewma estimation faster
55bb78d265c6 ath9k: dynack: remove 'experimental' tag

-- 
https://patchwork.kernel.org/patch/10666101/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

[PATCH 2/5] ath9k: dynack: move debug log after buffer increments

[Lorenzo Bianconi]

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>
---
 drivers/net/wireless/ath/ath9k/dynack.c | 26 ++++++++++++-------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c
index cc0dc966c512..5c969d833825 100644
--- 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 ath_hw *ah)
 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_hw *ah, struct sk_buff *skb,
 	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_hw *ah, struct sk_buff *skb,
 		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_hw *ah, struct sk_buff *skb,
 	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);
-- 
2.19.1

[PATCH 3/5] ath9k: dynack: check da->enabled first in sampling routines

[Lorenzo Bianconi]

Check da->enabled flag first in ath_dynack_sample_tx_ts and
ath_dynack_sample_ack_ts routines in order to avoid useless
processing

Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 drivers/net/wireless/ath/ath9k/dynack.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c
index 5c969d833825..5c3b32f4e61b 100644
--- a/drivers/net/wireless/ath/ath9k/dynack.c
+++ b/drivers/net/wireless/ath/ath9k/dynack.c
@@ -178,7 +178,7 @@ void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
 	u32 dur = ts->duration;
 	u8 ridx;
 
-	if ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !da->enabled)
+	if (!da->enabled || (info->flags & IEEE80211_TX_CTL_NO_ACK))
 		return;
 
 	spin_lock_bh(&da->qlock);
@@ -251,7 +251,7 @@ void ath_dynack_sample_ack_ts(struct ath_hw *ah, struct sk_buff *skb,
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 
-	if (!ath_dynack_bssidmask(ah, hdr->addr1) || !da->enabled)
+	if (!da->enabled || !ath_dynack_bssidmask(ah, hdr->addr1))
 		return;
 
 	spin_lock_bh(&da->qlock);
-- 
2.19.1

[PATCH 4/5] ath9k: dynack: make ewma estimation faster

[Lorenzo Bianconi]

In order to make propagation time estimation faster,
use current sample as ewma output value during 'late ack'
tracking

Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 drivers/net/wireless/ath/ath9k/ath9k.h  |  2 +-
 drivers/net/wireless/ath/ath9k/dynack.c | 28 ++++++++++++++++++-------
 drivers/net/wireless/ath/ath9k/dynack.h |  6 ++++--
 drivers/net/wireless/ath/ath9k/xmit.c   |  5 +++--
 4 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 21ba20981a80..0fca44e91a71 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -272,7 +272,7 @@ struct ath_node {
 #endif
 	u8 key_idx[4];
 
-	u32 ackto;
+	int ackto;
 	struct list_head list;
 };
 
diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c
index 5c3b32f4e61b..f112fa5b2eac 100644
--- a/drivers/net/wireless/ath/ath9k/dynack.c
+++ b/drivers/net/wireless/ath/ath9k/dynack.c
@@ -29,9 +29,13 @@
  * ath_dynack_ewma - EWMA (Exponentially Weighted Moving Average) calculation
  *
  */
-static inline u32 ath_dynack_ewma(u32 old, u32 new)
+static inline int ath_dynack_ewma(int old, int new)
 {
-	return (new * (EWMA_DIV - EWMA_LEVEL) + old * EWMA_LEVEL) / EWMA_DIV;
+	if (old > 0)
+		return (new * (EWMA_DIV - EWMA_LEVEL) +
+			old * EWMA_LEVEL) / EWMA_DIV;
+	else
+		return new;
 }
 
 /**
@@ -82,10 +86,10 @@ static inline bool ath_dynack_bssidmask(struct ath_hw *ah, const u8 *mac)
  */
 static void ath_dynack_compute_ackto(struct ath_hw *ah)
 {
-	struct ath_node *an;
-	u32 to = 0;
-	struct ath_dynack *da = &ah->dynack;
 	struct ath_common *common = ath9k_hw_common(ah);
+	struct ath_dynack *da = &ah->dynack;
+	struct ath_node *an;
+	int to = 0;
 
 	list_for_each_entry(an, &da->nodes, list)
 		if (an->ackto > to)
@@ -144,7 +148,8 @@ static void ath_dynack_compute_to(struct ath_hw *ah)
 					an->ackto = ath_dynack_ewma(an->ackto,
 								    ackto);
 					ath_dbg(ath9k_hw_common(ah), DYNACK,
-						"%pM to %u\n", dst, an->ackto);
+						"%pM to %d [%u]\n", dst,
+						an->ackto, ackto);
 					if (time_is_before_jiffies(da->lto)) {
 						ath_dynack_compute_ackto(ah);
 						da->lto = jiffies + COMPUTE_TO;
@@ -166,10 +171,12 @@ static void ath_dynack_compute_to(struct ath_hw *ah)
  * @ah: ath hw
  * @skb: socket buffer
  * @ts: tx status info
+ * @sta: station pointer
  *
  */
 void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
-			     struct ath_tx_status *ts)
+			     struct ath_tx_status *ts,
+			     struct ieee80211_sta *sta)
 {
 	struct ieee80211_hdr *hdr;
 	struct ath_dynack *da = &ah->dynack;
@@ -191,9 +198,16 @@ void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
 		    ieee80211_is_assoc_resp(hdr->frame_control) ||
 		    ieee80211_is_auth(hdr->frame_control)) {
 			ath_dbg(common, DYNACK, "late ack\n");
+
 			ath9k_hw_setslottime(ah, (LATEACK_TO - 3) / 2);
 			ath9k_hw_set_ack_timeout(ah, LATEACK_TO);
 			ath9k_hw_set_cts_timeout(ah, LATEACK_TO);
+			if (sta) {
+				struct ath_node *an;
+
+				an = (struct ath_node *)sta->drv_priv;
+				an->ackto = -1;
+			}
 			da->lto = jiffies + LATEACK_DELAY;
 		}
 
diff --git a/drivers/net/wireless/ath/ath9k/dynack.h b/drivers/net/wireless/ath/ath9k/dynack.h
index 6d7bef976742..cf60224d40df 100644
--- a/drivers/net/wireless/ath/ath9k/dynack.h
+++ b/drivers/net/wireless/ath/ath9k/dynack.h
@@ -86,7 +86,8 @@ void ath_dynack_node_deinit(struct ath_hw *ah, struct ath_node *an);
 void ath_dynack_init(struct ath_hw *ah);
 void ath_dynack_sample_ack_ts(struct ath_hw *ah, struct sk_buff *skb, u32 ts);
 void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
-			     struct ath_tx_status *ts);
+			     struct ath_tx_status *ts,
+			     struct ieee80211_sta *sta);
 #else
 static inline void ath_dynack_init(struct ath_hw *ah) {}
 static inline void ath_dynack_node_init(struct ath_hw *ah,
@@ -97,7 +98,8 @@ static inline void ath_dynack_sample_ack_ts(struct ath_hw *ah,
 					    struct sk_buff *skb, u32 ts) {}
 static inline void ath_dynack_sample_tx_ts(struct ath_hw *ah,
 					   struct sk_buff *skb,
-					   struct ath_tx_status *ts) {}
+					   struct ath_tx_status *ts,
+					   struct ieee80211_sta *sta) {}
 #endif
 
 #endif /* DYNACK_H */
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 25b3fc82d4ac..f448d5716639 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -629,7 +629,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 				if (bf == bf->bf_lastbf)
 					ath_dynack_sample_tx_ts(sc->sc_ah,
 								bf->bf_mpdu,
-								ts);
+								ts, sta);
 			}
 
 			ath_tx_complete_buf(sc, bf, txq, &bf_head, sta, ts,
@@ -773,7 +773,8 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
 			memcpy(info->control.rates, bf->rates,
 			       sizeof(info->control.rates));
 			ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok);
-			ath_dynack_sample_tx_ts(sc->sc_ah, bf->bf_mpdu, ts);
+			ath_dynack_sample_tx_ts(sc->sc_ah, bf->bf_mpdu, ts,
+						sta);
 		}
 		ath_tx_complete_buf(sc, bf, txq, bf_head, sta, ts, txok);
 	} else
-- 
2.19.1

[PATCH 5/5] ath9k: dynack: remove 'experimental' tag

[Lorenzo Bianconi]

Remove experimental tag from dynack Kconfig entry since it has
been tested on outdoor 25Km links

Tested-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
---
 drivers/net/wireless/ath/ath9k/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig
index 1f3523019509..ceca23a851d5 100644
--- a/drivers/net/wireless/ath/ath9k/Kconfig
+++ b/drivers/net/wireless/ath/ath9k/Kconfig
@@ -116,7 +116,7 @@ config ATH9K_DFS_CERTIFIED
 	  except increase code size.
 
 config ATH9K_DYNACK
-	bool "Atheros ath9k ACK timeout estimation algorithm (EXPERIMENTAL)"
+	bool "Atheros ath9k ACK timeout estimation algorithm"
 	depends on ATH9K
 	default n
 	---help---
-- 
2.19.1