From 020fa0f2f03ad7ef9c51cfda6a156b3cdf86b631 Mon Sep 17 00:00:00 2001
From: Koen Vandeputte <koen.vandeputte@ncentric.com>
Date: Wed, 11 Sep 2019 16:14:31 +0200
Subject: mac80211: IBSS: avoid unneeded return value processing

when ieee80211_ibss_csa_beacon() fails, we return it's value.
When it succeeds, we basically copy it's value and also .. return it.

Just return it immediately, simplifying the code.

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Link: https://lore.kernel.org/r/20190911141431.12498-1-koen.vandeputte@ncentric.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/ibss.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 0a6ff01c68a9..d40744903fa9 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -538,7 +538,6 @@ int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
 {
 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
 	struct cfg80211_bss *cbss;
-	int err, changed = 0;
 
 	sdata_assert_lock(sdata);
 
@@ -560,13 +559,7 @@ int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
 	ifibss->chandef = sdata->csa_chandef;
 
 	/* generate the beacon */
-	err = ieee80211_ibss_csa_beacon(sdata, NULL);
-	if (err < 0)
-		return err;
-
-	changed |= err;
-
-	return changed;
+	return ieee80211_ibss_csa_beacon(sdata, NULL);
 }
 
 void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
-- 
cgit v1.2.3


From 4fd0328d2f6314a40063cb2abcaed78976e3c022 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Tue, 1 Oct 2019 23:26:35 +0200
Subject: mac80211: pass internal sta to ieee80211_tx_frags()

This simplifies the code somewhat, and if necessary would let
us access the sta itself in that code.

Link: https://lore.kernel.org/r/1569965193-Id656db92703dded4bb2e3ec5dc329529f58e58f0@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/tx.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1fa422782905..938c10f7955b 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1617,7 +1617,7 @@ static bool ieee80211_queue_skb(struct ieee80211_local *local,
 
 static bool ieee80211_tx_frags(struct ieee80211_local *local,
 			       struct ieee80211_vif *vif,
-			       struct ieee80211_sta *sta,
+			       struct sta_info *sta,
 			       struct sk_buff_head *skbs,
 			       bool txpending)
 {
@@ -1679,7 +1679,7 @@ static bool ieee80211_tx_frags(struct ieee80211_local *local,
 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 
 		info->control.vif = vif;
-		control.sta = sta;
+		control.sta = sta ? &sta->sta : NULL;
 
 		__skb_unlink(skb, skbs);
 		drv_tx(local, &control, skb);
@@ -1698,7 +1698,6 @@ static bool __ieee80211_tx(struct ieee80211_local *local,
 	struct ieee80211_tx_info *info;
 	struct ieee80211_sub_if_data *sdata;
 	struct ieee80211_vif *vif;
-	struct ieee80211_sta *pubsta;
 	struct sk_buff *skb;
 	bool result = true;
 	__le16 fc;
@@ -1713,11 +1712,6 @@ static bool __ieee80211_tx(struct ieee80211_local *local,
 	if (sta && !sta->uploaded)
 		sta = NULL;
 
-	if (sta)
-		pubsta = &sta->sta;
-	else
-		pubsta = NULL;
-
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_MONITOR:
 		if (sdata->u.mntr.flags & MONITOR_FLAG_ACTIVE) {
@@ -1744,8 +1738,7 @@ static bool __ieee80211_tx(struct ieee80211_local *local,
 		break;
 	}
 
-	result = ieee80211_tx_frags(local, vif, pubsta, skbs,
-				    txpending);
+	result = ieee80211_tx_frags(local, vif, sta, skbs, txpending);
 
 	ieee80211_tpt_led_trig_tx(local, fc, led_len);
 
@@ -3529,7 +3522,7 @@ static bool ieee80211_xmit_fast(struct ieee80211_sub_if_data *sdata,
 				     struct ieee80211_sub_if_data, u.ap);
 
 	__skb_queue_tail(&tx.skbs, skb);
-	ieee80211_tx_frags(local, &sdata->vif, &sta->sta, &tx.skbs, false);
+	ieee80211_tx_frags(local, &sdata->vif, sta, &tx.skbs, false);
 	return true;
 }
 
-- 
cgit v1.2.3


From 2ce113de31320756b25179f3f4512a522bc45263 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Wed, 2 Oct 2019 11:12:25 +0200
Subject: mac80211: simplify TX aggregation start

There really is no need to make drivers call the
ieee80211_start_tx_ba_cb_irqsafe() function and then
schedule the worker if all we want is to set a bit.

Add a new return value (that was previously considered
invalid) to indicate that the driver is immediately
ready for the session, and make drivers use it. The
only drivers that remain different are the Intel ones
as they need to negotiate more with the firmware.

Link: https://lore.kernel.org/r/1570007543-I152912660131cbab2e5d80b4218238c20f8a06e5@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/agg-tx.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index b11883d26875..33da6f738c99 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -485,7 +485,14 @@ void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid)
 
 	params.ssn = sta->tid_seq[tid] >> 4;
 	ret = drv_ampdu_action(local, sdata, &params);
-	if (ret) {
+	if (ret == IEEE80211_AMPDU_TX_START_IMMEDIATE) {
+		/*
+		 * We didn't send the request yet, so don't need to check
+		 * here if we already got a response, just mark as driver
+		 * ready immediately.
+		 */
+		set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state);
+	} else if (ret) {
 		ht_dbg(sdata,
 		       "BA request denied - HW unavailable for %pM tid %d\n",
 		       sta->sta.addr, tid);
-- 
cgit v1.2.3


From 8f2f495ca93e01b383dc0944689e7595027ca6ec Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 8 Oct 2019 19:11:37 +0200
Subject: mac80211: minstrel: remove divisions in tx status path

Use a slightly different threshold for downgrading spatial streams to
make it easier to calculate without divisions.
Slightly reduces CPU overhead.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20191008171139.96476-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rc80211_minstrel.c    |  3 +--
 net/mac80211/rc80211_minstrel_ht.c | 10 ++++------
 2 files changed, 5 insertions(+), 8 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index ee86c3333999..f73017e08111 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -289,8 +289,7 @@ minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband,
 	if (mi->sample_deferred > 0)
 		mi->sample_deferred--;
 
-	if (time_after(jiffies, mi->last_stats_update +
-				(mp->update_interval * HZ) / 1000))
+	if (time_after(jiffies, mi->last_stats_update + mp->update_interval))
 		minstrel_update_stats(mp, mi);
 }
 
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 0ef2633349b5..21c74b200269 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -970,23 +970,21 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
 		 */
 		rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
 		if (rate->attempts > 30 &&
-		    MINSTREL_FRAC(rate->success, rate->attempts) <
-		    MINSTREL_FRAC(20, 100)) {
+		    rate->success < rate->attempts / 4) {
 			minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
 			update = true;
 		}
 
 		rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
 		if (rate2->attempts > 30 &&
-		    MINSTREL_FRAC(rate2->success, rate2->attempts) <
-		    MINSTREL_FRAC(20, 100)) {
+		    rate2->success < rate2->attempts / 4) {
 			minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
 			update = true;
 		}
 	}
 
 	if (time_after(jiffies, mi->last_stats_update +
-				(mp->update_interval / 2 * HZ) / 1000)) {
+				mp->update_interval / 2)) {
 		update = true;
 		minstrel_ht_update_stats(mp, mi, true);
 	}
@@ -1666,7 +1664,7 @@ minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 		mp->has_mrr = true;
 
 	mp->hw = hw;
-	mp->update_interval = 100;
+	mp->update_interval = HZ / 10;
 
 #ifdef CONFIG_MAC80211_DEBUGFS
 	mp->fixed_rate_idx = (u32) -1;
-- 
cgit v1.2.3


From b1103d256704869f94c1399d189618c43724ded6 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 8 Oct 2019 19:11:38 +0200
Subject: mac80211: minstrel_ht: replace rate stats ewma with a better moving
 average

Rate success probability usually fluctuates a lot under normal conditions.
With a simple EWMA, noise and fluctuation can be reduced by increasing the
window length, but that comes at the cost of introducing lag on sudden
changes.

This change replaces the EWMA implementation with a moving average that's
designed to significantly reduce lag while keeping a bigger window size
by being better at filtering out noise.

It is only slightly more expensive than the simple EWMA and still avoids
divisions in its calculation.

The algorithm is adapted from an implementation intended for a completely
different field (stock market trading), where the tradeoff of lag vs
noise filtering is equally important. It is based on the "smoothing filter"
from http://www.stockspotter.com/files/PredictiveIndicators.pdf.

I have adapted it to fixed-point math with some constants so that it uses
only addition, bit shifts and multiplication

To better make use of the filtering and bigger window size, the update
interval time is cut in half.

For testing, the algorithm can be reverted to the older one via debugfs

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20191008171139.96476-2-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rc80211_minstrel.c    | 13 ++++++---
 net/mac80211/rc80211_minstrel.h    | 56 +++++++++++++++++++++++++++++++++++++-
 net/mac80211/rc80211_minstrel_ht.c | 15 ++++++++--
 3 files changed, 76 insertions(+), 8 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index f73017e08111..d9b7bc7fdb33 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -157,14 +157,18 @@ minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 * Recalculate statistics and counters of a given rate
 */
 void
-minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs)
+minstrel_calc_rate_stats(struct minstrel_priv *mp,
+			 struct minstrel_rate_stats *mrs)
 {
 	unsigned int cur_prob;
 
 	if (unlikely(mrs->attempts > 0)) {
 		mrs->sample_skipped = 0;
 		cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
-		if (unlikely(!mrs->att_hist)) {
+		if (mp->new_avg) {
+			mrs->prob_ewma = minstrel_filter_avg_add(&mrs->avg,
+								 cur_prob);
+		} else if (unlikely(!mrs->att_hist)) {
 			mrs->prob_ewma = cur_prob;
 		} else {
 			/*update exponential weighted moving avarage */
@@ -200,7 +204,7 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 		struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats;
 
 		/* Update statistics of success probability per rate */
-		minstrel_calc_rate_stats(mrs);
+		minstrel_calc_rate_stats(mp, mrs);
 
 		/* Sample less often below the 10% chance of success.
 		 * Sample less often above the 95% chance of success. */
@@ -289,7 +293,8 @@ minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband,
 	if (mi->sample_deferred > 0)
 		mi->sample_deferred--;
 
-	if (time_after(jiffies, mi->last_stats_update + mp->update_interval))
+	if (time_after(jiffies, mi->last_stats_update +
+				mp->update_interval / (mp->new_avg ? 2 : 1)))
 		minstrel_update_stats(mp, mi);
 }
 
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 51d8b2c846e7..31f6f02ab765 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -18,6 +18,21 @@
 /* number of highest throughput rates to consider*/
 #define MAX_THR_RATES 4
 
+/*
+ * Coefficients for moving average with noise filter (period=16),
+ * scaled by 10 bits
+ *
+ * a1 = exp(-pi * sqrt(2) / period)
+ * coeff2 = 2 * a1 * cos(sqrt(2) * 2 * pi / period)
+ * coeff3 = -sqr(a1)
+ * coeff1 = 1 - coeff2 - coeff3
+ */
+#define MINSTREL_AVG_COEFF1		(MINSTREL_FRAC(1, 1) - \
+					 MINSTREL_AVG_COEFF2 - \
+					 MINSTREL_AVG_COEFF3)
+#define MINSTREL_AVG_COEFF2		0x00001499
+#define MINSTREL_AVG_COEFF3		-0x0000092e
+
 /*
  * Perform EWMA (Exponentially Weighted Moving Average) calculation
  */
@@ -32,6 +47,41 @@ minstrel_ewma(int old, int new, int weight)
 	return old + incr;
 }
 
+struct minstrel_avg_ctx {
+	s32 prev[2];
+};
+
+static inline int minstrel_filter_avg_add(struct minstrel_avg_ctx *ctx, s32 in)
+{
+	s32 out_1 = ctx->prev[0];
+	s32 out_2 = ctx->prev[1];
+	s32 val;
+
+	if (!in)
+		in += 1;
+
+	if (!out_1) {
+		val = out_1 = in;
+		goto out;
+	}
+
+	val = MINSTREL_AVG_COEFF1 * in;
+	val += MINSTREL_AVG_COEFF2 * out_1;
+	val += MINSTREL_AVG_COEFF3 * out_2;
+	val >>= MINSTREL_SCALE;
+
+	if (val > 1 << MINSTREL_SCALE)
+		val = 1 << MINSTREL_SCALE;
+	if (val < 0)
+		val = 1;
+
+out:
+	ctx->prev[1] = out_1;
+	ctx->prev[0] = val;
+
+	return val;
+}
+
 struct minstrel_rate_stats {
 	/* current / last sampling period attempts/success counters */
 	u16 attempts, last_attempts;
@@ -40,6 +90,8 @@ struct minstrel_rate_stats {
 	/* total attempts/success counters */
 	u32 att_hist, succ_hist;
 
+	struct minstrel_avg_ctx avg;
+
 	/* prob_ewma - exponential weighted moving average of prob */
 	u16 prob_ewma;
 
@@ -95,6 +147,7 @@ struct minstrel_sta_info {
 struct minstrel_priv {
 	struct ieee80211_hw *hw;
 	bool has_mrr;
+	bool new_avg;
 	u32 sample_switch;
 	unsigned int cw_min;
 	unsigned int cw_max;
@@ -126,7 +179,8 @@ extern const struct rate_control_ops mac80211_minstrel;
 void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 
 /* Recalculate success probabilities and counters for a given rate using EWMA */
-void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
+void minstrel_calc_rate_stats(struct minstrel_priv *mp,
+			      struct minstrel_rate_stats *mrs);
 int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
 
 /* debugfs */
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 21c74b200269..96c81392e617 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -737,7 +737,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 
 			mrs = &mg->rates[i];
 			mrs->retry_updated = false;
-			minstrel_calc_rate_stats(mrs);
+			minstrel_calc_rate_stats(mp, mrs);
 			cur_prob = mrs->prob_ewma;
 
 			if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
@@ -773,6 +773,8 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 
 	/* try to sample all available rates during each interval */
 	mi->sample_count *= 8;
+	if (mp->new_avg)
+		mi->sample_count /= 2;
 
 	if (sample)
 		minstrel_ht_rate_sample_switch(mp, mi);
@@ -889,6 +891,7 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
 	struct ieee80211_tx_rate *ar = info->status.rates;
 	struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL;
 	struct minstrel_priv *mp = priv;
+	u32 update_interval = mp->update_interval / 2;
 	bool last, update = false;
 	bool sample_status = false;
 	int i;
@@ -943,6 +946,10 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
 
 	switch (mi->sample_mode) {
 	case MINSTREL_SAMPLE_IDLE:
+		if (mp->new_avg &&
+		    (mp->hw->max_rates > 1 ||
+		     mi->total_packets_cur < SAMPLE_SWITCH_THR))
+			update_interval /= 2;
 		break;
 
 	case MINSTREL_SAMPLE_ACTIVE:
@@ -983,8 +990,7 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
 		}
 	}
 
-	if (time_after(jiffies, mi->last_stats_update +
-				mp->update_interval / 2)) {
+	if (time_after(jiffies, mi->last_stats_update + update_interval)) {
 		update = true;
 		minstrel_ht_update_stats(mp, mi, true);
 	}
@@ -1665,6 +1671,7 @@ minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 
 	mp->hw = hw;
 	mp->update_interval = HZ / 10;
+	mp->new_avg = true;
 
 #ifdef CONFIG_MAC80211_DEBUGFS
 	mp->fixed_rate_idx = (u32) -1;
@@ -1672,6 +1679,8 @@ minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 			   &mp->fixed_rate_idx);
 	debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir,
 			   &mp->sample_switch);
+	debugfs_create_bool("new_avg", S_IRUGO | S_IWUSR, debugfsdir,
+			   &mp->new_avg);
 #endif
 
 	minstrel_ht_init_cck_rates(mp);
-- 
cgit v1.2.3


From 5f63afe0288d9553a9560725d7abbf3fc899a5da Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 8 Oct 2019 19:11:39 +0200
Subject: mac80211: minstrel_ht: rename prob_ewma to prob_avg, use it for the
 new average

Reduces per-rate data structure size

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20191008171139.96476-3-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rc80211_minstrel.c            | 40 ++++++++++++------------
 net/mac80211/rc80211_minstrel.h            | 23 ++++++--------
 net/mac80211/rc80211_minstrel_debugfs.c    |  8 ++---
 net/mac80211/rc80211_minstrel_ht.c         | 50 +++++++++++++++---------------
 net/mac80211/rc80211_minstrel_ht.h         |  2 +-
 net/mac80211/rc80211_minstrel_ht_debugfs.c |  8 ++---
 6 files changed, 63 insertions(+), 68 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index d9b7bc7fdb33..86bc469a28bc 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -70,7 +70,7 @@ rix_to_ndx(struct minstrel_sta_info *mi, int rix)
 }
 
 /* return current EMWA throughput */
-int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma)
+int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_avg)
 {
 	int usecs;
 
@@ -79,13 +79,13 @@ int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma)
 		usecs = 1000000;
 
 	/* reset thr. below 10% success */
-	if (mr->stats.prob_ewma < MINSTREL_FRAC(10, 100))
+	if (mr->stats.prob_avg < MINSTREL_FRAC(10, 100))
 		return 0;
 
-	if (prob_ewma > MINSTREL_FRAC(90, 100))
+	if (prob_avg > MINSTREL_FRAC(90, 100))
 		return MINSTREL_TRUNC(100000 * (MINSTREL_FRAC(90, 100) / usecs));
 	else
-		return MINSTREL_TRUNC(100000 * (prob_ewma / usecs));
+		return MINSTREL_TRUNC(100000 * (prob_avg / usecs));
 }
 
 /* find & sort topmost throughput rates */
@@ -98,8 +98,8 @@ minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list)
 
 	for (j = MAX_THR_RATES; j > 0; --j) {
 		tmp_mrs = &mi->r[tp_list[j - 1]].stats;
-		if (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_ewma) <=
-		    minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_ewma))
+		if (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_avg) <=
+		    minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_avg))
 			break;
 	}
 
@@ -166,15 +166,15 @@ minstrel_calc_rate_stats(struct minstrel_priv *mp,
 		mrs->sample_skipped = 0;
 		cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
 		if (mp->new_avg) {
-			mrs->prob_ewma = minstrel_filter_avg_add(&mrs->avg,
-								 cur_prob);
+			minstrel_filter_avg_add(&mrs->prob_avg,
+						&mrs->prob_avg_1, cur_prob);
 		} else if (unlikely(!mrs->att_hist)) {
-			mrs->prob_ewma = cur_prob;
+			mrs->prob_avg = cur_prob;
 		} else {
 			/*update exponential weighted moving avarage */
-			mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma,
-						       cur_prob,
-						       EWMA_LEVEL);
+			mrs->prob_avg = minstrel_ewma(mrs->prob_avg,
+						      cur_prob,
+						      EWMA_LEVEL);
 		}
 		mrs->att_hist += mrs->attempts;
 		mrs->succ_hist += mrs->success;
@@ -208,8 +208,8 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 
 		/* Sample less often below the 10% chance of success.
 		 * Sample less often above the 95% chance of success. */
-		if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
-		    mrs->prob_ewma < MINSTREL_FRAC(10, 100)) {
+		if (mrs->prob_avg > MINSTREL_FRAC(95, 100) ||
+		    mrs->prob_avg < MINSTREL_FRAC(10, 100)) {
 			mr->adjusted_retry_count = mrs->retry_count >> 1;
 			if (mr->adjusted_retry_count > 2)
 				mr->adjusted_retry_count = 2;
@@ -229,14 +229,14 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 		 * choose the maximum throughput rate as max_prob_rate
 		 * (2) if all success probabilities < 95%, the rate with
 		 * highest success probability is chosen as max_prob_rate */
-		if (mrs->prob_ewma >= MINSTREL_FRAC(95, 100)) {
-			tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_ewma);
+		if (mrs->prob_avg >= MINSTREL_FRAC(95, 100)) {
+			tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_avg);
 			tmp_prob_tp = minstrel_get_tp_avg(&mi->r[tmp_prob_rate],
-							  tmp_mrs->prob_ewma);
+							  tmp_mrs->prob_avg);
 			if (tmp_cur_tp >= tmp_prob_tp)
 				tmp_prob_rate = i;
 		} else {
-			if (mrs->prob_ewma >= tmp_mrs->prob_ewma)
+			if (mrs->prob_avg >= tmp_mrs->prob_avg)
 				tmp_prob_rate = i;
 		}
 	}
@@ -426,7 +426,7 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
 	 * has a probability of >95%, we shouldn't be attempting
 	 * to use it, as this only wastes precious airtime */
 	if (!mrr_capable &&
-	   (mi->r[ndx].stats.prob_ewma > MINSTREL_FRAC(95, 100)))
+	   (mi->r[ndx].stats.prob_avg > MINSTREL_FRAC(95, 100)))
 		return;
 
 	mi->prev_sample = true;
@@ -577,7 +577,7 @@ static u32 minstrel_get_expected_throughput(void *priv_sta)
 	 * computing cur_tp
 	 */
 	tmp_mrs = &mi->r[idx].stats;
-	tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma) * 10;
+	tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_avg) * 10;
 	tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024;
 
 	return tmp_cur_tp;
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 31f6f02ab765..dbb43bcd3c45 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -47,14 +47,10 @@ minstrel_ewma(int old, int new, int weight)
 	return old + incr;
 }
 
-struct minstrel_avg_ctx {
-	s32 prev[2];
-};
-
-static inline int minstrel_filter_avg_add(struct minstrel_avg_ctx *ctx, s32 in)
+static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
 {
-	s32 out_1 = ctx->prev[0];
-	s32 out_2 = ctx->prev[1];
+	s32 out_1 = *prev_1;
+	s32 out_2 = *prev_2;
 	s32 val;
 
 	if (!in)
@@ -76,8 +72,8 @@ static inline int minstrel_filter_avg_add(struct minstrel_avg_ctx *ctx, s32 in)
 		val = 1;
 
 out:
-	ctx->prev[1] = out_1;
-	ctx->prev[0] = val;
+	*prev_2 = out_1;
+	*prev_1 = val;
 
 	return val;
 }
@@ -90,10 +86,9 @@ struct minstrel_rate_stats {
 	/* total attempts/success counters */
 	u32 att_hist, succ_hist;
 
-	struct minstrel_avg_ctx avg;
-
-	/* prob_ewma - exponential weighted moving average of prob */
-	u16 prob_ewma;
+	/* prob_avg - moving average of prob */
+	u16 prob_avg;
+	u16 prob_avg_1;
 
 	/* maximum retry counts */
 	u8 retry_count;
@@ -181,7 +176,7 @@ void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 /* Recalculate success probabilities and counters for a given rate using EWMA */
 void minstrel_calc_rate_stats(struct minstrel_priv *mp,
 			      struct minstrel_rate_stats *mrs);
-int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
+int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_avg);
 
 /* debugfs */
 int minstrel_stats_open(struct inode *inode, struct file *file);
diff --git a/net/mac80211/rc80211_minstrel_debugfs.c b/net/mac80211/rc80211_minstrel_debugfs.c
index c8afd85b51a0..9b8e0daeb7bb 100644
--- a/net/mac80211/rc80211_minstrel_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_debugfs.c
@@ -90,8 +90,8 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 		p += sprintf(p, "%6u ", mr->perfect_tx_time);
 
 		tp_max = minstrel_get_tp_avg(mr, MINSTREL_FRAC(100,100));
-		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_ewma);
-		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_avg);
+		eprob = MINSTREL_TRUNC(mrs->prob_avg * 1000);
 
 		p += sprintf(p, "%4u.%1u    %4u.%1u     %3u.%1u"
 				"     %3u   %3u %-3u   "
@@ -147,8 +147,8 @@ minstrel_stats_csv_open(struct inode *inode, struct file *file)
 		p += sprintf(p, "%u,",mr->perfect_tx_time);
 
 		tp_max = minstrel_get_tp_avg(mr, MINSTREL_FRAC(100,100));
-		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_ewma);
-		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_avg);
+		eprob = MINSTREL_TRUNC(mrs->prob_avg * 1000);
 
 		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u,%u,%u,"
 				"%llu,%llu,%d,%d\n",
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 96c81392e617..694a31978a04 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -346,12 +346,12 @@ minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
  */
 int
 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
-		       int prob_ewma)
+		       int prob_avg)
 {
 	unsigned int nsecs = 0;
 
 	/* do not account throughput if sucess prob is below 10% */
-	if (prob_ewma < MINSTREL_FRAC(10, 100))
+	if (prob_avg < MINSTREL_FRAC(10, 100))
 		return 0;
 
 	if (group != MINSTREL_CCK_GROUP)
@@ -365,11 +365,11 @@ minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
 	 * account for collision related packet error rate fluctuation
 	 * (prob is scaled - see MINSTREL_FRAC above)
 	 */
-	if (prob_ewma > MINSTREL_FRAC(90, 100))
+	if (prob_avg > MINSTREL_FRAC(90, 100))
 		return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
 								      / nsecs));
 	else
-		return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
+		return MINSTREL_TRUNC(100000 * ((prob_avg * 1000) / nsecs));
 }
 
 /*
@@ -389,13 +389,13 @@ minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
 
 	cur_group = index / MCS_GROUP_RATES;
 	cur_idx = index  % MCS_GROUP_RATES;
-	cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
+	cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
 	cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
 
 	do {
 		tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
 		tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
-		tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+		tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 		tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
 						    tmp_prob);
 		if (cur_tp_avg < tmp_tp_avg ||
@@ -432,7 +432,7 @@ minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
 
 	tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
 	tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
-	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 	tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 
 	/* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
@@ -444,11 +444,11 @@ minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
 
 	max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
 	max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
-	max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
+	max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
 
-	if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
+	if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
 		cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
-						    mrs->prob_ewma);
+						    mrs->prob_avg);
 		if (cur_tp_avg > tmp_tp_avg)
 			mi->max_prob_rate = index;
 
@@ -458,9 +458,9 @@ minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
 		if (cur_tp_avg > max_gpr_tp_avg)
 			mg->max_group_prob_rate = index;
 	} else {
-		if (mrs->prob_ewma > tmp_prob)
+		if (mrs->prob_avg > tmp_prob)
 			mi->max_prob_rate = index;
-		if (mrs->prob_ewma > max_gpr_prob)
+		if (mrs->prob_avg > max_gpr_prob)
 			mg->max_group_prob_rate = index;
 	}
 }
@@ -482,12 +482,12 @@ minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
 
 	tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
 	tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
-	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 	tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 
 	tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
 	tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
-	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+	tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 	tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 
 	if (tmp_cck_tp_rate && tmp_cck_tp > tmp_mcs_tp) {
@@ -518,7 +518,7 @@ minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
 			continue;
 
 		tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
-		tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
+		tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
 
 		if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
 		   (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
@@ -623,7 +623,7 @@ minstrel_ht_rate_sample_switch(struct minstrel_priv *mp,
 	 * If that fails, look again for a rate that is at least as fast
 	 */
 	mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
-	faster_rate = mrs->prob_ewma > MINSTREL_FRAC(75, 100);
+	faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100);
 	minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate);
 	if (!n_rates && faster_rate)
 		minstrel_ht_find_probe_rates(mi, rates, &n_rates, false);
@@ -738,7 +738,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 			mrs = &mg->rates[i];
 			mrs->retry_updated = false;
 			minstrel_calc_rate_stats(mp, mrs);
-			cur_prob = mrs->prob_ewma;
+			cur_prob = mrs->prob_avg;
 
 			if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
 				continue;
@@ -1012,7 +1012,7 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 	unsigned int overhead = 0, overhead_rtscts = 0;
 
 	mrs = minstrel_get_ratestats(mi, index);
-	if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
+	if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
 		mrs->retry_count = 1;
 		mrs->retry_count_rtscts = 1;
 		return;
@@ -1069,7 +1069,7 @@ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 	if (!mrs->retry_updated)
 		minstrel_calc_retransmit(mp, mi, index);
 
-	if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
+	if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
 		ratetbl->rate[offset].count = 2;
 		ratetbl->rate[offset].count_rts = 2;
 		ratetbl->rate[offset].count_cts = 2;
@@ -1103,11 +1103,11 @@ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 }
 
 static inline int
-minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
+minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
 {
 	int group = rate / MCS_GROUP_RATES;
 	rate %= MCS_GROUP_RATES;
-	return mi->groups[group].rates[rate].prob_ewma;
+	return mi->groups[group].rates[rate].prob_avg;
 }
 
 static int
@@ -1119,7 +1119,7 @@ minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
 	unsigned int duration;
 
 	/* Disable A-MSDU if max_prob_rate is bad */
-	if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
+	if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
 		return 1;
 
 	duration = g->duration[rate];
@@ -1142,7 +1142,7 @@ minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
 	 * data packet size
 	 */
 	if (duration > MCS_DURATION(1, 0, 260) ||
-	    (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
+	    (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
 	     MINSTREL_FRAC(75, 100)))
 		return 3200;
 
@@ -1247,7 +1247,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 	 * rate, to avoid wasting airtime.
 	 */
 	sample_dur = minstrel_get_duration(sample_idx);
-	if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
+	if (mrs->prob_avg > MINSTREL_FRAC(95, 100) ||
 	    minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
 		return -1;
 
@@ -1705,7 +1705,7 @@ static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
 
 	i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
 	j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
-	prob = mi->groups[i].rates[j].prob_ewma;
+	prob = mi->groups[i].rates[j].prob_avg;
 
 	/* convert tp_avg from pkt per second in kbps */
 	tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
diff --git a/net/mac80211/rc80211_minstrel_ht.h b/net/mac80211/rc80211_minstrel_ht.h
index f938701e7ab7..53ea3c29debf 100644
--- a/net/mac80211/rc80211_minstrel_ht.h
+++ b/net/mac80211/rc80211_minstrel_ht.h
@@ -119,6 +119,6 @@ struct minstrel_ht_sta_priv {
 
 void minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 int minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
-			   int prob_ewma);
+			   int prob_avg);
 
 #endif
diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index 5a6e9f3edc04..bebb71917742 100644
--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
@@ -98,8 +98,8 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		p += sprintf(p, "%6u  ", tx_time);
 
 		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
-		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_ewma);
-		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_avg);
+		eprob = MINSTREL_TRUNC(mrs->prob_avg * 1000);
 
 		p += sprintf(p, "%4u.%1u    %4u.%1u     %3u.%1u"
 				"     %3u   %3u %-3u   "
@@ -243,8 +243,8 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		p += sprintf(p, "%u,", tx_time);
 
 		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
-		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_ewma);
-		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_avg);
+		eprob = MINSTREL_TRUNC(mrs->prob_avg * 1000);
 
 		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u,%u,"
 				"%u,%llu,%llu,",
-- 
cgit v1.2.3