mac80211: update to wireless-testing 2010-03-03

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@20032 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 0 insertions, 1115 deletions

diff --git a/package/mac80211/patches/590-minstrel_ht.patch b/package/mac80211/patches/590-minstrel_ht.patch
deleted file mode 100644
index 30b8b8043b..0000000000
--- a/package/mac80211/patches/590-minstrel_ht.patch
+++ /dev/null
@@ -1,1115 +0,0 @@
---- a/net/mac80211/Makefile
-+++ b/net/mac80211/Makefile
-@@ -47,8 +47,8 @@ CFLAGS_driver-trace.o := -I$(src)
- rc80211_pid-y := rc80211_pid_algo.o
- rc80211_pid-$(CONFIG_MAC80211_DEBUGFS) += rc80211_pid_debugfs.o
- 
--rc80211_minstrel-y := rc80211_minstrel.o
--rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o
-+rc80211_minstrel-y := rc80211_minstrel.o rc80211_minstrel_ht.o
-+rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o rc80211_minstrel_ht_debugfs.o
- 
- mac80211-$(CONFIG_MAC80211_RC_PID) += $(rc80211_pid-y)
- mac80211-$(CONFIG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)
---- a/net/mac80211/main.c
-+++ b/net/mac80211/main.c
-@@ -710,6 +710,10 @@ static int __init ieee80211_init(void)
- 	if (ret)
- 		return ret;
- 
-+	ret = rc80211_minstrel_ht_init();
-+	if (ret)
-+		goto err_minstrel;
-+
- 	ret = rc80211_pid_init();
- 	if (ret)
- 		goto err_pid;
-@@ -722,6 +726,8 @@ static int __init ieee80211_init(void)
-  err_netdev:
- 	rc80211_pid_exit();
-  err_pid:
-+	rc80211_minstrel_ht_exit();
-+ err_minstrel:
- 	rc80211_minstrel_exit();
- 
- 	return ret;
-@@ -730,6 +736,7 @@ static int __init ieee80211_init(void)
- static void __exit ieee80211_exit(void)
- {
- 	rc80211_pid_exit();
-+	rc80211_minstrel_ht_exit();
- 	rc80211_minstrel_exit();
- 
- 	/*
---- a/net/mac80211/rate.h
-+++ b/net/mac80211/rate.h
-@@ -136,6 +136,8 @@ static inline void rc80211_pid_exit(void
- #ifdef CONFIG_MAC80211_RC_MINSTREL
- extern int rc80211_minstrel_init(void);
- extern void rc80211_minstrel_exit(void);
-+extern int rc80211_minstrel_ht_init(void);
-+extern void rc80211_minstrel_ht_exit(void);
- #else
- static inline int rc80211_minstrel_init(void)
- {
-@@ -144,6 +146,13 @@ static inline int rc80211_minstrel_init(
- static inline void rc80211_minstrel_exit(void)
- {
- }
-+static inline int rc80211_minstrel_ht_init(void)
-+{
-+	return 0;
-+}
-+static inline void rc80211_minstrel_ht_exit(void)
-+{
-+}
- #endif
- 
- 
---- /dev/null
-+++ b/net/mac80211/rc80211_minstrel_ht.c
-@@ -0,0 +1,803 @@
-+/*
-+ * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/netdevice.h>
-+#include <linux/types.h>
-+#include <linux/skbuff.h>
-+#include <linux/debugfs.h>
-+#include <linux/random.h>
-+#include <linux/ieee80211.h>
-+#include <net/mac80211.h>
-+#include "rate.h"
-+#include "rc80211_minstrel.h"
-+#include "rc80211_minstrel_ht.h"
-+
-+#define AVG_PKT_SIZE	1200
-+#define SAMPLE_COLUMNS	10
-+#define EWMA_LEVEL		75
-+
-+/* Number of bits for an average sized packet */
-+#define MCS_NBITS (AVG_PKT_SIZE << 3)
-+
-+/* Number of symbols for a packet with (bps) bits per symbol */
-+#define MCS_NSYMS(bps) ((MCS_NBITS + (bps) - 1) / (bps))
-+
-+/* Transmission time for a packet containing (syms) symbols */
-+#define MCS_SYMBOL_TIME(sgi, syms)					\
-+	(sgi ?								\
-+	  ((syms) * 18 + 4) / 5 :	/* syms * 3.6 us */		\
-+	  (syms) << 2			/* syms * 4 us */		\
-+	)
-+
-+/* Transmit duration for the raw data part of an average sized packet */
-+#define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
-+
-+/* MCS rate information for an MCS group */
-+#define MCS_GROUP(_streams, _sgi, _ht40) {				\
-+	.streams = _streams,						\
-+	.flags =							\
-+		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
-+		(_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),		\
-+	.duration = {							\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26),		\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52),		\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78),		\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104),	\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156),	\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208),	\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234),	\
-+		MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260)		\
-+	}								\
-+}
-+
-+#define MINSTREL_INTFL_SAMPLE_SLOT0	BIT(30)
-+#define MINSTREL_INTFL_SAMPLE_SLOT1	BIT(31)
-+
-+/*
-+ * To enable sufficiently targeted rate sampling, MCS rates are divided into
-+ * groups, based on the number of streams and flags (HT40, SGI) that they
-+ * use.
-+ */
-+const struct mcs_group minstrel_mcs_groups[] = {
-+	MCS_GROUP(1, 0, 0),
-+	MCS_GROUP(2, 0, 0),
-+#if MINSTREL_MAX_STREAMS >= 3
-+	MCS_GROUP(3, 0, 0),
-+#endif
-+
-+	MCS_GROUP(1, 1, 0),
-+	MCS_GROUP(2, 1, 0),
-+#if MINSTREL_MAX_STREAMS >= 3
-+	MCS_GROUP(3, 1, 0),
-+#endif
-+
-+	MCS_GROUP(1, 0, 1),
-+	MCS_GROUP(2, 0, 1),
-+#if MINSTREL_MAX_STREAMS >= 3
-+	MCS_GROUP(3, 0, 1),
-+#endif
-+
-+	MCS_GROUP(1, 1, 1),
-+	MCS_GROUP(2, 1, 1),
-+#if MINSTREL_MAX_STREAMS >= 3
-+	MCS_GROUP(3, 1, 1),
-+#endif
-+};
-+
-+static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];
-+
-+/*
-+ * Perform EWMA (Exponentially Weighted Moving Average) calculation
-+ */
-+static int
-+minstrel_ewma(int old, int new, int weight)
-+{
-+	return (new * (100 - weight) + old * weight) / 100;
-+}
-+
-+/*
-+ * Look up an MCS group index based on mac80211 rate information
-+ */
-+static int
-+minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
-+{
-+	int streams = (rate->idx / MCS_GROUP_RATES) + 1;
-+	u32 flags = IEEE80211_TX_RC_SHORT_GI | IEEE80211_TX_RC_40_MHZ_WIDTH;
-+	int i;
-+
-+	for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
-+		if (minstrel_mcs_groups[i].streams != streams)
-+			continue;
-+		if (minstrel_mcs_groups[i].flags != (rate->flags & flags))
-+			continue;
-+
-+		return i;
-+	}
-+
-+	WARN_ON(1);
-+	return 0;
-+}
-+
-+static inline struct minstrel_rate_stats *
-+minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
-+{
-+	return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
-+}
-+
-+
-+/*
-+ * Recalculate success probabilities and counters for a rate using EWMA
-+ */
-+static void
-+minstrel_calc_rate_ewma(struct minstrel_priv *mp, struct minstrel_rate_stats *mr)
-+{
-+	if (mr->attempts) {
-+		mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
-+		if (!mr->att_hist)
-+			mr->probability = mr->cur_prob;
-+		else
-+			mr->probability = minstrel_ewma(mr->probability,
-+				mr->cur_prob, EWMA_LEVEL);
-+		mr->att_hist += mr->attempts;
-+		mr->succ_hist += mr->success;
-+	}
-+	mr->last_success = mr->success;
-+	mr->last_attempts = mr->attempts;
-+	mr->success = 0;
-+	mr->attempts = 0;
-+}
-+
-+/*
-+ * Calculate throughput based on the average A-MPDU length, taking into account
-+ * the expected number of retransmissions and their expected length
-+ */
-+static void
-+minstrel_ht_calc_tp(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
-+                    int group, int rate)
-+{
-+	struct minstrel_rate_stats *mr;
-+	unsigned int usecs;
-+
-+	mr = &mi->groups[group].rates[rate];
-+
-+	if (mr->probability < MINSTREL_FRAC(1, 10)) {
-+		mr->cur_tp = 0;
-+		return;
-+	}
-+
-+	usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
-+	usecs += minstrel_mcs_groups[group].duration[rate];
-+	mr->cur_tp = MINSTREL_TRUNC((1000000 / usecs) * mr->probability);
-+}
-+
-+/*
-+ * Update rate statistics and select new primary rates
-+ *
-+ * Rules for rate selection:
-+ *  - max_prob_rate must use only one stream, as a tradeoff between delivery
-+ *    probability and throughput during strong fluctuations
-+ *  - as long as the max prob rate has a probability of more than 3/4, pick
-+ *    higher throughput rates, even if the probablity is a bit lower
-+ */
-+static void
-+minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
-+{
-+	struct minstrel_mcs_group_data *mg;
-+	struct minstrel_rate_stats *mr;
-+	int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
-+	int group, i, index;
-+
-+	mi->max_tp_rate = 0;
-+	mi->max_tp_rate2 = 0;
-+	mi->max_prob_rate = 0;
-+
-+	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
-+		cur_prob = 0;
-+		cur_prob_tp = 0;
-+		cur_tp = 0;
-+		cur_tp2 = 0;
-+
-+		mg = &mi->groups[group];
-+		if (!mg->supported)
-+			continue;
-+
-+		mg->max_tp_rate = 0;
-+		mg->max_tp_rate2 = 0;
-+		mg->max_prob_rate = 0;
-+
-+		for (i = 0; i < MCS_GROUP_RATES; i++) {
-+			if (!(mg->supported & BIT(i)))
-+				continue;
-+
-+			mr = &mg->rates[i];
-+			mr->retry_updated = false;
-+			index = MCS_GROUP_RATES * group + i;
-+			minstrel_calc_rate_ewma(mp, mr);
-+			minstrel_ht_calc_tp(mp, mi, group, i);
-+
-+			if (!mr->cur_tp)
-+				continue;
-+
-+			/* ignore the lowest rate of each single-stream group */
-+			if (!i && minstrel_mcs_groups[group].streams == 1)
-+				continue;
-+
-+			if ((mr->cur_tp > cur_prob_tp && mr->probability >
-+			     MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
-+				mg->max_prob_rate = index;
-+				cur_prob = mr->probability;
-+			}
-+
-+			if (mr->cur_tp > cur_tp) {
-+				swap(index, mg->max_tp_rate);
-+				cur_tp = mr->cur_tp;
-+				mr = minstrel_get_ratestats(mi, index);
-+			}
-+
-+			if (index == mg->max_tp_rate)
-+				continue;
-+
-+			if (mr->cur_tp > cur_tp2) {
-+				mg->max_tp_rate2 = index;
-+				cur_tp2 = mr->cur_tp;
-+			}
-+		}
-+	}
-+
-+	cur_prob = 0;
-+	cur_prob_tp = 0;
-+	cur_tp = 0;
-+	cur_tp2 = 0;
-+	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
-+		mg = &mi->groups[group];
-+		if (!mg->supported)
-+			continue;
-+
-+		mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
-+		if (cur_prob_tp < mr->cur_tp &&
-+		    minstrel_mcs_groups[group].streams == 1) {
-+			mi->max_prob_rate = mg->max_prob_rate;
-+			cur_prob = mr->cur_prob;
-+		}
-+
-+		mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
-+		if (cur_tp < mr->cur_tp) {
-+			mi->max_tp_rate = mg->max_tp_rate;
-+			cur_tp = mr->cur_tp;
-+		}
-+
-+		mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
-+		if (cur_tp2 < mr->cur_tp) {
-+			mi->max_tp_rate2 = mg->max_tp_rate2;
-+			cur_tp2 = mr->cur_tp;
-+		}
-+	}
-+
-+	mi->stats_update = jiffies;
-+}
-+
-+static bool
-+minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
-+{
-+	if (!rate->count)
-+		return false;
-+
-+	if (rate->idx < 0)
-+		return false;
-+
-+	return !!(rate->flags & IEEE80211_TX_RC_MCS);
-+}
-+
-+static void
-+minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
-+{
-+	struct minstrel_mcs_group_data *mg;
-+
-+	for (;;) {
-+		mi->sample_group++;
-+		mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
-+		mg = &mi->groups[mi->sample_group];
-+
-+		if (!mg->supported)
-+			continue;
-+
-+		if (++mg->index > MCS_GROUP_RATES) {
-+			mg->index = 0;
-+			if (++mg->column > ARRAY_SIZE(sample_table))
-+				mg->column = 0;
-+		}
-+		break;
-+	}
-+}
-+
-+static void
-+minstrel_downgrade_rate(struct minstrel_ht_sta *mi, int *idx, int type)
-+{
-+	int group, orig_group;
-+
-+	orig_group = group = *idx / MCS_GROUP_RATES;
-+	while (group > 0) {
-+		group--;
-+
-+		if (!mi->groups[group].supported)
-+			continue;
-+
-+		if (minstrel_mcs_groups[group].streams >=
-+		    minstrel_mcs_groups[orig_group].streams)
-+			continue;
-+
-+		switch(type) {
-+		case 0:
-+			*idx = mi->groups[group].max_tp_rate;
-+			break;
-+		case 1:
-+			*idx = mi->groups[group].max_tp_rate2;
-+			break;
-+		}
-+		break;
-+	}
-+}
-+
-+
-+static void
-+minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
-+                      struct ieee80211_sta *sta, void *priv_sta,
-+                      struct sk_buff *skb)
-+{
-+	struct minstrel_ht_sta_priv *msp = priv_sta;
-+	struct minstrel_ht_sta *mi = &msp->ht;
-+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-+	struct ieee80211_tx_rate *ar = info->status.rates;
-+	struct minstrel_rate_stats *rate, *rate2;
-+	struct minstrel_priv *mp = priv;
-+	bool last = false;
-+	int group;
-+	int i = 0;
-+
-+	if (!msp->is_ht)
-+		return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
-+
-+	/* This packet was aggregated but doesn't carry status info */
-+	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
-+	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
-+		return;
-+
-+	if (!info->status.ampdu_len) {
-+		info->status.ampdu_ack_len = 1;
-+		info->status.ampdu_len = 1;
-+	}
-+
-+	mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
-+		MINSTREL_FRAC(info->status.ampdu_len, 1), 90);
-+
-+	for (i = 0; !last; i++) {
-+		last = (i == IEEE80211_TX_MAX_RATES - 1) ||
-+		       !minstrel_ht_txstat_valid(&ar[i + 1]);
-+
-+		if (!minstrel_ht_txstat_valid(&ar[i]))
-+			break;
-+
-+		if ((i == 0 && (info->flags & MINSTREL_INTFL_SAMPLE_SLOT0)) ||
-+		    (i == 1 && (info->flags & MINSTREL_INTFL_SAMPLE_SLOT1))) {
-+			if (mi->sample_pending > 0)
-+				mi->sample_pending--;
-+			mi->sample_packets++;
-+			minstrel_next_sample_idx(mi);
-+		}
-+
-+		group = minstrel_ht_get_group_idx(&ar[i]);
-+		rate = &mi->groups[group].rates[ar[i].idx % 8];
-+
-+		if (last && (info->flags & IEEE80211_TX_STAT_ACK) &&
-+		    info->status.ampdu_len == info->status.ampdu_ack_len)
-+			rate->success++;
-+
-+		rate->attempts += ar[i].count;
-+	}
-+
-+
-+	/*
-+	 * check for sudden death of spatial multiplexing,
-+	 * downgrade to a lower number of streams if necessary.
-+	 */
-+	rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
-+	if (MINSTREL_FRAC(rate->success, rate->attempts) <
-+	    MINSTREL_FRAC(20, 100) && rate->attempts > 15)
-+		minstrel_downgrade_rate(mi, &mi->max_tp_rate, 0);
-+
-+	rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
-+	if (MINSTREL_FRAC(rate->success, rate->attempts) <
-+	    MINSTREL_FRAC(20, 100) && rate->attempts > 15)
-+		minstrel_downgrade_rate(mi, &mi->max_tp_rate2, 1);
-+
-+	if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000))
-+		minstrel_ht_update_stats(mp, mi);
-+}
-+
-+static void
-+minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
-+                         int index)
-+{
-+	struct minstrel_rate_stats *mr;
-+	const struct mcs_group *group;
-+	unsigned int tx_time, tx_time_rtscts, tx_time_data;
-+	unsigned int cw = mp->cw_min;
-+	unsigned int t_slot = 9; /* FIXME */
-+	unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
-+
-+	mr = minstrel_get_ratestats(mi, index);
-+	if (mr->probability < MINSTREL_FRAC(1, 10)) {
-+		mr->retry_count = 1;
-+		mr->retry_count_rtscts = 1;
-+		return;
-+	}
-+
-+	mr->retry_count = 2;
-+	mr->retry_count_rtscts = 2;
-+	mr->retry_updated = true;
-+
-+	group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
-+	tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
-+	tx_time = 2 * (t_slot + mi->overhead + tx_time_data);
-+	tx_time_rtscts = 2 * (t_slot + mi->overhead_rtscts + tx_time_data);
-+	do {
-+		cw = (cw << 1) | 1;
-+		cw = min(cw, mp->cw_max);
-+		tx_time += cw + t_slot + mi->overhead;
-+		tx_time_rtscts += cw + t_slot + mi->overhead_rtscts;
-+		if (tx_time_rtscts < mp->segment_size)
-+			mr->retry_count_rtscts++;
-+	} while ((tx_time < mp->segment_size) &&
-+	         (++mr->retry_count < mp->max_retry));
-+}
-+
-+
-+static void
-+minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
-+                     struct ieee80211_tx_rate *rate, int index,
-+                     struct ieee80211_tx_rate_control *txrc,
-+                     bool sample, bool rtscts)
-+{
-+	const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
-+	struct minstrel_rate_stats *mr;
-+
-+	mr = minstrel_get_ratestats(mi, index);
-+	if (!mr->retry_updated)
-+		minstrel_calc_retransmit(mp, mi, index);
-+
-+	if (rtscts)
-+		rate->count = mr->retry_count_rtscts;
-+	else
-+		rate->count = mr->retry_count;
-+
-+	rate->flags = IEEE80211_TX_RC_MCS | group->flags;
-+	if (txrc->short_preamble)
-+		rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
-+	if (txrc->rts || rtscts)
-+		rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
-+	rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
-+}
-+
-+static inline int
-+minstrel_get_duration(int index)
-+{
-+	const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
-+	return group->duration[index % MCS_GROUP_RATES];
-+}
-+
-+static int
-+minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
-+                         bool *defer)
-+{
-+	struct minstrel_rate_stats *mr;
-+	struct minstrel_mcs_group_data *mg;
-+	int sample_idx = 0;
-+	int sample_rate;
-+	int delta;
-+
-+	if (mp->has_mrr)
-+		sample_rate = mp->lookaround_rate_mrr;
-+	else
-+		sample_rate = mp->lookaround_rate;
-+
-+	delta = (mi->total_packets * sample_rate) / 100 - mi->sample_packets;
-+	delta -= mi->sample_pending / 2;
-+
-+	if (delta <= 0)
-+		return -1;
-+
-+	delta -= 16;
-+	if (delta > 1) {
-+		/* With multi-rate retry, not every planned sample
-+		* attempt actually gets used, due to the way the retry
-+		* chain is set up - [max_tp,sample,prob,lowest] for
-+		* sample_rate < max_tp.
-+		*
-+		* If there's too much sampling backlog and the link
-+		* starts getting worse, minstrel would start bursting
-+		* out lots of sampling frames, which would result
-+		* in a large throughput loss.
-+		*/
-+		mi->sample_packets += delta - 1;
-+	}
-+
-+	mg = &mi->groups[mi->sample_group];
-+	sample_idx = sample_table[mg->column][mg->index];
-+	mr = &mg->rates[sample_idx];
-+	sample_idx += mi->sample_group * MCS_GROUP_RATES;
-+
-+	/*
-+	 * When not using MRR, do not sample if the probability is already
-+	 * higher than 95% to avoid wasting airtime
-+	 */
-+	if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
-+		return -1;
-+
-+	if (minstrel_get_duration(sample_idx) >
-+	    minstrel_get_duration(mi->max_tp_rate)) {
-+		/*
-+		 * Make sure that lower rates get sampled occasionally, even
-+		 * if the link is working perfectly. Some drivers such as ath9k
-+		 * severely limit aggregation size if the MRR chain contains low
-+		 * rates
-+		 *
-+		 * If the lower rate has already been tried a few times, there's
-+		 * no point in forcing it to be sampled again, so skip to the
-+		 * next sampling index after applying this one in the tx control
-+		 */
-+		if (mr->att_hist > 15) {
-+			*defer = true;
-+			minstrel_next_sample_idx(mi);
-+		}
-+	}
-+
-+	return sample_idx;
-+}
-+
-+static void
-+minstrel_aggr_check(struct minstrel_priv *mp, struct ieee80211_sta *pubsta, struct sk_buff *skb)
-+{
-+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-+	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
-+	u16 tid;
-+
-+	if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
-+		return;
-+
-+	if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
-+		return;
-+
-+	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
-+	if (likely(sta->ampdu_mlme.tid_state_tx[tid] != HT_AGG_STATE_IDLE))
-+		return;
-+
-+	ieee80211_start_tx_ba_session(pubsta, tid);
-+}
-+
-+static void
-+minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
-+                     struct ieee80211_tx_rate_control *txrc)
-+{
-+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
-+	struct ieee80211_tx_rate *ar = info->status.rates;
-+	struct minstrel_ht_sta_priv *msp = priv_sta;
-+	struct minstrel_ht_sta *mi = &msp->ht;
-+	struct minstrel_priv *mp = priv;
-+	bool sample_defer = false;
-+	int sample_idx;
-+
-+	if (rate_control_send_low(sta, priv_sta, txrc))
-+		return;
-+
-+	if (!msp->is_ht)
-+		return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
-+
-+	minstrel_aggr_check(mp, sta, txrc->skb);
-+
-+	sample_idx = minstrel_get_sample_rate(mp, mi, &sample_defer);
-+	if (sample_idx >= 0) {
-+		if (sample_defer) {
-+			minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
-+				txrc, false, false);
-+			minstrel_ht_set_rate(mp, mi, &ar[1], sample_idx,
-+				txrc, true, true);
-+			info->flags |= MINSTREL_INTFL_SAMPLE_SLOT1;
-+		} else {
-+			minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
-+				txrc, true, false);
-+			minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
-+				txrc, false, true);
-+			info->flags |= MINSTREL_INTFL_SAMPLE_SLOT0;
-+		}
-+		mi->sample_pending++;
-+	} else {
-+		minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
-+			txrc, false, false);
-+		minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
-+			txrc, false, true);
-+	}
-+	minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate, txrc, false, true);
-+
-+	ar[3].count = 0;
-+	ar[3].idx = -1;
-+
-+	mi->total_packets++;
-+
-+	/* wraparound */
-+	if (mi->total_packets >= 100000) {
-+		mi->total_packets = 0;
-+		mi->sample_packets = 0;
-+		mi->sample_pending = 0;
-+	}
-+}
-+
-+
-+static void
-+minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
-+                      struct ieee80211_sta *sta, void *priv_sta)
-+{
-+	struct minstrel_priv *mp = priv;
-+	struct minstrel_ht_sta_priv *msp = priv_sta;
-+	struct minstrel_ht_sta *mi = &msp->ht;
-+	struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
-+	struct ieee80211_local *local = hw_to_local(mp->hw);
-+	int tx_streams;
-+	int ack_dur;
-+	int i;
-+
-+	/* fall back to the old minstrel for legacy stations */
-+	if (sta && !sta->ht_cap.ht_supported) {
-+		msp->is_ht = false;
-+		memset(&msp->legacy, 0, sizeof(msp->legacy));
-+		msp->legacy.r = msp->ratelist;
-+		msp->legacy.sample_table = msp->sample_table;
-+		return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
-+	}
-+
-+	BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
-+		MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
-+
-+	msp->is_ht = true;
-+	memset(mi, 0, sizeof(*mi));
-+	mi->stats_update = jiffies;
-+
-+	ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1);
-+	mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur;
-+	mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
-+
-+	mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
-+	tx_streams = ((mcs->tx_params & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK) >>
-+			IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
-+
-+	for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
-+		u16 req = 0;
-+
-+		if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
-+			if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
-+				req |= IEEE80211_HT_CAP_SGI_40;
-+			else
-+				req |= IEEE80211_HT_CAP_SGI_20;
-+		}
-+
-+		if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
-+			req |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
-+
-+		if ((sta->ht_cap.cap & req) != req)
-+			continue;
-+
-+		mi->groups[i].supported =
-+			mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
-+	}
-+}
-+
-+static void *
-+minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
-+{
-+	struct ieee80211_supported_band *sband;
-+	struct minstrel_ht_sta_priv *msp;
-+	struct minstrel_priv *mp = priv;
-+	struct ieee80211_hw *hw = mp->hw;
-+	int max_rates = 0;
-+	int i;
-+
-+	for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
-+		sband = hw->wiphy->bands[i];
-+		if (sband && sband->n_bitrates > max_rates)
-+			max_rates = sband->n_bitrates;
-+	}
-+
-+	msp = kzalloc(sizeof(struct minstrel_ht_sta), gfp);
-+	if (!msp)
-+		return NULL;
-+
-+	msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
-+	if (!msp->ratelist)
-+		goto error;
-+
-+	msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
-+	if (!msp->sample_table)
-+		goto error1;
-+
-+	return msp;
-+
-+error1:
-+	kfree(msp->sample_table);
-+error:
-+	kfree(msp);
-+	return NULL;
-+}
-+
-+static void
-+minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
-+{
-+	struct minstrel_ht_sta_priv *msp = priv_sta;
-+
-+	kfree(msp->sample_table);
-+	kfree(msp->ratelist);
-+	kfree(msp);
-+}
-+
-+static void *
-+minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
-+{
-+	return mac80211_minstrel.alloc(hw, debugfsdir);
-+}
-+
-+static void
-+minstrel_ht_free(void *priv)
-+{
-+	mac80211_minstrel.free(priv);
-+}
-+
-+static struct rate_control_ops mac80211_minstrel_ht = {
-+	.name = "minstrel_ht",
-+	.tx_status = minstrel_ht_tx_status,
-+	.get_rate = minstrel_ht_get_rate,
-+	.rate_init = minstrel_ht_rate_init,
-+	.alloc_sta = minstrel_ht_alloc_sta,
-+	.free_sta = minstrel_ht_free_sta,
-+	.alloc = minstrel_ht_alloc,
-+	.free = minstrel_ht_free,
-+#ifdef CONFIG_MAC80211_DEBUGFS
-+	.add_sta_debugfs = minstrel_ht_add_sta_debugfs,
-+	.remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
-+#endif
-+};
-+
-+
-+static void
-+init_sample_table(void)
-+{
-+	int col, i, new_idx;
-+	u8 rnd[MCS_GROUP_RATES];
-+
-+	memset(sample_table, 0xff, sizeof(sample_table));
-+	for (col = 0; col < SAMPLE_COLUMNS; col++) {
-+		for (i = 0; i < MCS_GROUP_RATES; i++) {
-+			get_random_bytes(rnd, sizeof(rnd));
-+			new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
-+
-+			while (sample_table[col][new_idx] != 0xff)
-+				new_idx = (new_idx + 1) % MCS_GROUP_RATES;
-+
-+			sample_table[col][new_idx] = i;
-+		}
-+	}
-+}
-+
-+int __init
-+rc80211_minstrel_ht_init(void)
-+{
-+	init_sample_table();
-+	return ieee80211_rate_control_register(&mac80211_minstrel_ht);
-+}
-+
-+void
-+rc80211_minstrel_ht_exit(void)
-+{
-+	ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
-+}
---- /dev/null
-+++ b/net/mac80211/rc80211_minstrel_ht.h
-@@ -0,0 +1,115 @@
-+/*
-+ * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+
-+#ifndef __RC_MINSTREL_HT_H
-+#define __RC_MINSTREL_HT_H
-+
-+/*
-+ * maximum number of spatial streams to make use of
-+ * set this value to 3 once we have drivers that support it
-+ */
-+#define MINSTREL_MAX_STREAMS	2
-+#define MINSTREL_STREAM_GROUPS	4
-+
-+/* scaled fraction values */
-+#define MINSTREL_SCALE	16
-+#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
-+#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
-+
-+#define MCS_GROUP_RATES	8
-+
-+struct mcs_group {
-+	u32 flags;
-+	unsigned int streams;
-+	unsigned int duration[MCS_GROUP_RATES];
-+};
-+
-+struct minstrel_rate_stats {
-+	/* current / last sampling period attempts/success counters */
-+	unsigned int attempts, last_attempts;
-+	unsigned int success, last_success;
-+
-+	/* total attempts/success counters */
-+	u64 att_hist, succ_hist;
-+
-+	/* current throughput */
-+	unsigned int cur_tp;
-+
-+	/* packet delivery probabilities */
-+	unsigned int cur_prob, probability;
-+
-+	/* maximum retry counts */
-+	bool retry_updated;
-+	unsigned int retry_count;
-+	unsigned int retry_count_rtscts;
-+};
-+
-+struct minstrel_mcs_group_data {
-+	u8 index;
-+	u8 column;
-+
-+	/* bitfield of supported MCS rates of this group */
-+	u8 supported;
-+
-+	/* selected primary rates */
-+	unsigned int max_tp_rate;
-+	unsigned int max_tp_rate2;
-+	unsigned int max_prob_rate;
-+
-+	/* MCS rate statistics */
-+	struct minstrel_rate_stats rates[MCS_GROUP_RATES];
-+};
-+
-+struct minstrel_ht_sta {
-+	/* ampdu length average (EWMA) */
-+	unsigned int avg_ampdu_len;
-+
-+	/* best throughput rate */
-+	unsigned int max_tp_rate;
-+
-+	/* second best throughput rate */
-+	unsigned int max_tp_rate2;
-+
-+	/* best probability rate */
-+	unsigned int max_prob_rate;
-+
-+	/* time of last status update */
-+	unsigned long stats_update;
-+
-+	/* overhead time in usec for each frame */
-+	unsigned int overhead;
-+	unsigned int overhead_rtscts;
-+
-+	unsigned int total_packets;
-+	unsigned int sample_packets;
-+	unsigned int sample_pending;
-+
-+	/* current MCS group to be sampled */
-+	unsigned int sample_group;
-+
-+	/* MCS rate group info and statistics */
-+	struct minstrel_mcs_group_data groups[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS];
-+};
-+
-+struct minstrel_ht_sta_priv {
-+	union {
-+		struct minstrel_ht_sta ht;
-+		struct minstrel_sta_info legacy;
-+	};
-+#ifdef CONFIG_MAC80211_DEBUGFS
-+	struct dentry *dbg_stats;
-+#endif
-+	void *ratelist;
-+	void *sample_table;
-+	bool is_ht;
-+};
-+
-+void minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
-+void minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta);
-+
-+#endif
---- /dev/null
-+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
-@@ -0,0 +1,120 @@
-+/*
-+ * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/netdevice.h>
-+#include <linux/types.h>
-+#include <linux/skbuff.h>
-+#include <linux/debugfs.h>
-+#include <linux/ieee80211.h>
-+#include <net/mac80211.h>
-+#include "rc80211_minstrel.h"
-+#include "rc80211_minstrel_ht.h"
-+
-+extern const struct mcs_group minstrel_mcs_groups[];
-+
-+static int
-+minstrel_ht_stats_open(struct inode *inode, struct file *file)
-+{
-+	struct minstrel_ht_sta_priv *msp = inode->i_private;
-+	struct minstrel_ht_sta *mi = &msp->ht;
-+	struct minstrel_debugfs_info *ms;
-+	unsigned int i, j, tp, prob, eprob;
-+	char *p;
-+	int ret;
-+
-+	if (!msp->is_ht) {
-+		inode->i_private = &msp->legacy;
-+		ret = minstrel_stats_open(inode, file);
-+		inode->i_private = msp;
-+		return ret;
-+	}
-+
-+	ms = kmalloc(sizeof(*ms) + 8192, GFP_KERNEL);
-+	if (!ms)
-+		return -ENOMEM;
-+
-+	file->private_data = ms;
-+	p = ms->buf;
-+	p += sprintf(p, "type      rate     throughput  ewma prob   this prob  "
-+			"this succ/attempt   success    attempts\n");
-+	for (i = 0; i < MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS; i++) {
-+		char htmode = '2';
-+		char gimode = 'L';
-+
-+		if (!mi->groups[i].supported)
-+			continue;
-+
-+		if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
-+			htmode = '4';
-+		if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI)
-+			gimode = 'S';
-+
-+		for (j = 0; j < MCS_GROUP_RATES; j++) {
-+			struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
-+			int idx = i * MCS_GROUP_RATES + j;
-+
-+			if (!mi->groups[i].supported & BIT(j))
-+				continue;
-+
-+			p += sprintf(p, "HT%c0/%cGI ", htmode, gimode);
-+
-+			*(p++) = (idx == mi->max_tp_rate) ? 'T' : ' ';
-+			*(p++) = (idx == mi->max_tp_rate2) ? 't' : ' ';
-+			*(p++) = (idx == mi->max_prob_rate) ? 'P' : ' ';
-+			p += sprintf(p, "MCS%-2u", (minstrel_mcs_groups[i].streams - 1) *
-+					MCS_GROUP_RATES + j);
-+
-+			tp = mr->cur_tp / 10;
-+			prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
-+			eprob = MINSTREL_TRUNC(mr->probability * 1000);
-+
-+			p += sprintf(p, "  %6u.%1u   %6u.%1u   %6u.%1u        "
-+					"%3u(%3u)   %8llu    %8llu\n",
-+					tp / 10, tp % 10,
-+					eprob / 10, eprob % 10,
-+					prob / 10, prob % 10,
-+					mr->last_success,
-+					mr->last_attempts,
-+					(unsigned long long)mr->succ_hist,
-+					(unsigned long long)mr->att_hist);
-+		}
-+	}
-+	p += sprintf(p, "\nTotal packet count::    ideal %d      "
-+			"lookaround %d\n",
-+			max(0, (int) mi->total_packets - (int) mi->sample_packets),
-+			mi->sample_packets);
-+	p += sprintf(p, "Average A-MPDU length: %d.%d\n",
-+		MINSTREL_TRUNC(mi->avg_ampdu_len),
-+		MINSTREL_TRUNC(mi->avg_ampdu_len * 10) % 10);
-+	ms->len = p - ms->buf;
-+
-+	return 0;
-+}
-+
-+static const struct file_operations minstrel_ht_stat_fops = {
-+	.owner = THIS_MODULE,
-+	.open = minstrel_ht_stats_open,
-+	.read = minstrel_stats_read,
-+	.release = minstrel_stats_release,
-+};
-+
-+void
-+minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
-+{
-+	struct minstrel_ht_sta_priv *msp = priv_sta;
-+
-+	msp->dbg_stats = debugfs_create_file("rc_stats", S_IRUGO, dir, msp,
-+			&minstrel_ht_stat_fops);
-+}
-+
-+void
-+minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta)
-+{
-+	struct minstrel_ht_sta_priv *msp = priv_sta;
-+
-+	debugfs_remove(msp->dbg_stats);
-+}