mac80211: replace legacy minstrel with minstrel_ht, improve rate selection

Legacy minstrel is essentially unmaintained and was showing poor performance
Replace it with minstrel_ht and improve rate selection and sampling behavior

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 762 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/subsys/338-mac80211-minstrel_ht-add-support-for-OFDM-rates-on-n.patch b/package/kernel/mac80211/patches/subsys/338-mac80211-minstrel_ht-add-support-for-OFDM-rates-on-n.patch
new file mode 100644
index 0000000000..abefde7109
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/338-mac80211-minstrel_ht-add-support-for-OFDM-rates-on-n.patch
@@ -0,0 +1,762 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Sat, 26 Dec 2020 13:56:42 +0100
+Subject: [PATCH] mac80211: minstrel_ht: add support for OFDM rates on
+ non-HT clients
+
+The legacy minstrel code is essentially unmaintained and receives only very
+little testing. In order to bring the significant algorithm improvements from
+minstrel_ht to legacy clients, this patch adds support for OFDM rates to
+minstrel_ht and removes the fallback to the legacy codepath.
+This also makes it work much better on hardware with rate selection constraints,
+e.g. mt76.
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/net/mac80211/rc80211_minstrel.h
++++ b/net/mac80211/rc80211_minstrel.h
+@@ -152,6 +152,7 @@ struct minstrel_priv {
+ 	unsigned int lookaround_rate_mrr;
+ 
+ 	u8 cck_rates[4];
++	u8 ofdm_rates[NUM_NL80211_BANDS][8];
+ 
+ #ifdef CPTCFG_MAC80211_DEBUGFS
+ 	/*
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -163,6 +163,38 @@
+ 
+ #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
+ 
++#define OFDM_DURATION(_bitrate)				\
++	(1000 * (16 /* SIFS + signal ext */ +		\
++	 16 /* T_PREAMBLE */ +				\
++	 4 /* T_SIGNAL */ +				\
++	 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) /	\
++	      ((_bitrate) * 4)))))
++
++#define OFDM_DURATION_LIST(_s)				\
++	OFDM_DURATION(60) >> _s,			\
++	OFDM_DURATION(90) >> _s,			\
++	OFDM_DURATION(120) >> _s,			\
++	OFDM_DURATION(180) >> _s,			\
++	OFDM_DURATION(240) >> _s,			\
++	OFDM_DURATION(360) >> _s,			\
++	OFDM_DURATION(480) >> _s,			\
++	OFDM_DURATION(540) >> _s
++
++#define __OFDM_GROUP(_s)				\
++	[MINSTREL_OFDM_GROUP] = {			\
++		.streams = 1,				\
++		.flags = 0,				\
++		.shift = _s,				\
++		.duration = {				\
++			OFDM_DURATION_LIST(_s),		\
++		}					\
++	}
++
++#define OFDM_GROUP_SHIFT				\
++	GROUP_SHIFT(OFDM_DURATION(60))
++
++#define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT)
++
+ 
+ static bool minstrel_vht_only = true;
+ module_param(minstrel_vht_only, bool, 0644);
+@@ -199,6 +231,7 @@ const struct mcs_group minstrel_mcs_grou
+ 	MCS_GROUP(4, 1, BW_40),
+ 
+ 	CCK_GROUP,
++	OFDM_GROUP,
+ 
+ 	VHT_GROUP(1, 0, BW_20),
+ 	VHT_GROUP(2, 0, BW_20),
+@@ -231,6 +264,8 @@ const struct mcs_group minstrel_mcs_grou
+ 	VHT_GROUP(4, 1, BW_80),
+ };
+ 
++const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
++const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
+ static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
+ 
+ static void
+@@ -275,6 +310,13 @@ minstrel_get_valid_vht_rates(int bw, int
+ 	return 0x3ff & ~mask;
+ }
+ 
++static bool
++minstrel_ht_is_legacy_group(int group)
++{
++	return group == MINSTREL_CCK_GROUP ||
++	       group == MINSTREL_OFDM_GROUP;
++}
++
+ /*
+  * Look up an MCS group index based on mac80211 rate information
+  */
+@@ -304,21 +346,34 @@ minstrel_ht_get_stats(struct minstrel_pr
+ 	if (rate->flags & IEEE80211_TX_RC_MCS) {
+ 		group = minstrel_ht_get_group_idx(rate);
+ 		idx = rate->idx % 8;
+-	} else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
++		goto out;
++	}
++
++	if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
+ 		group = minstrel_vht_get_group_idx(rate);
+ 		idx = ieee80211_rate_get_vht_mcs(rate);
+-	} else {
+-		group = MINSTREL_CCK_GROUP;
++		goto out;
++	}
+ 
+-		for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
+-			if (rate->idx == mp->cck_rates[idx])
+-				break;
++	group = MINSTREL_CCK_GROUP;
++	for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
++		if (rate->idx != mp->cck_rates[idx])
++			continue;
+ 
+ 		/* short preamble */
+ 		if ((mi->supported[group] & BIT(idx + 4)) &&
+ 		    (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
+-			idx += 4;
++				idx += 4;
++		goto out;
+ 	}
++
++	group = MINSTREL_OFDM_GROUP;
++	for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
++		if (rate->idx == mp->ofdm_rates[mi->band][idx])
++			goto out;
++
++	idx = 0;
++out:
+ 	return &mi->groups[group].rates[idx];
+ }
+ 
+@@ -352,7 +407,7 @@ minstrel_ht_get_tp_avg(struct minstrel_h
+ 	if (prob_avg < MINSTREL_FRAC(10, 100))
+ 		return 0;
+ 
+-	if (group == MINSTREL_CCK_GROUP)
++	if (minstrel_ht_is_legacy_group(group))
+ 		overhead = mi->overhead_legacy;
+ 	else
+ 		ampdu_len = minstrel_ht_avg_ampdu_len(mi);
+@@ -439,8 +494,8 @@ minstrel_ht_set_best_prob_rate(struct mi
+ 	/* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
+ 	 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
+ 	max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
+-	if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
+-	    (max_tp_group != MINSTREL_CCK_GROUP))
++	if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES) &&
++	    !minstrel_ht_is_legacy_group(max_tp_group))
+ 		return;
+ 
+ 	max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
+@@ -476,13 +531,13 @@ minstrel_ht_set_best_prob_rate(struct mi
+ static void
+ minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
+ 				 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
+-				 u16 tmp_cck_tp_rate[MAX_THR_RATES])
++				 u16 tmp_legacy_tp_rate[MAX_THR_RATES])
+ {
+ 	unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
+ 	int i;
+ 
+-	tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
+-	tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
++	tmp_group = tmp_legacy_tp_rate[0] / MCS_GROUP_RATES;
++	tmp_idx = tmp_legacy_tp_rate[0] % MCS_GROUP_RATES;
+ 	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);
+ 
+@@ -493,7 +548,7 @@ minstrel_ht_assign_best_tp_rates(struct
+ 
+ 	if (tmp_cck_tp > tmp_mcs_tp) {
+ 		for(i = 0; i < MAX_THR_RATES; i++) {
+-			minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
++			minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
+ 						       tmp_mcs_tp_rate);
+ 		}
+ 	}
+@@ -511,6 +566,9 @@ minstrel_ht_prob_rate_reduce_streams(str
+ 	int tmp_max_streams, group, tmp_idx, tmp_prob;
+ 	int tmp_tp = 0;
+ 
++	if (!mi->sta->ht_cap.ht_supported)
++		return;
++
+ 	tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
+ 			  MCS_GROUP_RATES].streams;
+ 	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
+@@ -675,7 +733,8 @@ minstrel_ht_update_stats(struct minstrel
+ 	struct minstrel_rate_stats *mrs;
+ 	int group, i, j, cur_prob;
+ 	u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
+-	u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
++	u16 tmp_legacy_tp_rate[MAX_THR_RATES], index;
++	bool ht_supported = mi->sta->ht_cap.ht_supported;
+ 
+ 	mi->sample_mode = MINSTREL_SAMPLE_IDLE;
+ 
+@@ -704,21 +763,29 @@ minstrel_ht_update_stats(struct minstrel
+ 	mi->sample_count = 0;
+ 
+ 	memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate));
+-	memset(tmp_cck_tp_rate, 0, sizeof(tmp_cck_tp_rate));
++	memset(tmp_legacy_tp_rate, 0, sizeof(tmp_legacy_tp_rate));
+ 	if (mi->supported[MINSTREL_CCK_GROUP])
+-		for (j = 0; j < ARRAY_SIZE(tmp_cck_tp_rate); j++)
+-			tmp_cck_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
++		for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
++			tmp_legacy_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
++	else if (mi->supported[MINSTREL_OFDM_GROUP])
++		for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
++			tmp_legacy_tp_rate[j] = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES;
+ 
+ 	if (mi->supported[MINSTREL_VHT_GROUP_0])
+ 		index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES;
+-	else
++	else if (ht_supported)
+ 		index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES;
++	else if (mi->supported[MINSTREL_CCK_GROUP])
++		index = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
++	else
++		index = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES;
+ 
+ 	for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
+ 		tmp_mcs_tp_rate[j] = index;
+ 
+ 	/* Find best rate sets within all MCS groups*/
+ 	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
++		u16 *tp_rate = tmp_mcs_tp_rate;
+ 
+ 		mg = &mi->groups[group];
+ 		if (!mi->supported[group])
+@@ -730,6 +797,9 @@ minstrel_ht_update_stats(struct minstrel
+ 		for(j = 0; j < MAX_THR_RATES; j++)
+ 			tmp_group_tp_rate[j] = MCS_GROUP_RATES * group;
+ 
++		if (group == MINSTREL_CCK_GROUP && ht_supported)
++			tp_rate = tmp_legacy_tp_rate;
++
+ 		for (i = 0; i < MCS_GROUP_RATES; i++) {
+ 			if (!(mi->supported[group] & BIT(i)))
+ 				continue;
+@@ -745,13 +815,7 @@ minstrel_ht_update_stats(struct minstrel
+ 				continue;
+ 
+ 			/* Find max throughput rate set */
+-			if (group != MINSTREL_CCK_GROUP) {
+-				minstrel_ht_sort_best_tp_rates(mi, index,
+-							       tmp_mcs_tp_rate);
+-			} else if (group == MINSTREL_CCK_GROUP) {
+-				minstrel_ht_sort_best_tp_rates(mi, index,
+-							       tmp_cck_tp_rate);
+-			}
++			minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
+ 
+ 			/* Find max throughput rate set within a group */
+ 			minstrel_ht_sort_best_tp_rates(mi, index,
+@@ -766,7 +830,8 @@ minstrel_ht_update_stats(struct minstrel
+ 	}
+ 
+ 	/* Assign new rate set per sta */
+-	minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
++	minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
++					 tmp_legacy_tp_rate);
+ 	memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
+ 
+ 	/* Try to increase robustness of max_prob_rate*/
+@@ -795,8 +860,11 @@ minstrel_ht_update_stats(struct minstrel
+ }
+ 
+ static bool
+-minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
++minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
++			 struct ieee80211_tx_rate *rate)
+ {
++	int i;
++
+ 	if (rate->idx < 0)
+ 		return false;
+ 
+@@ -807,10 +875,15 @@ minstrel_ht_txstat_valid(struct minstrel
+ 	    rate->flags & IEEE80211_TX_RC_VHT_MCS)
+ 		return true;
+ 
+-	return rate->idx == mp->cck_rates[0] ||
+-	       rate->idx == mp->cck_rates[1] ||
+-	       rate->idx == mp->cck_rates[2] ||
+-	       rate->idx == mp->cck_rates[3];
++	for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
++		if (rate->idx == mp->cck_rates[i])
++			return true;
++
++	for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
++		if (rate->idx == mp->ofdm_rates[mi->band][i])
++			return true;
++
++	return false;
+ }
+ 
+ static void
+@@ -897,11 +970,6 @@ minstrel_ht_tx_status(void *priv, struct
+ 	bool sample_status = false;
+ 	int i;
+ 
+-	if (!msp->is_ht)
+-		return mac80211_minstrel.tx_status_ext(priv, sband,
+-						       &msp->legacy, st);
+-
+-
+ 	/* This packet was aggregated but doesn't carry status info */
+ 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
+ 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
+@@ -930,10 +998,10 @@ minstrel_ht_tx_status(void *priv, struct
+ 	if (mi->sample_mode != MINSTREL_SAMPLE_IDLE)
+ 		rate_sample = minstrel_get_ratestats(mi, mi->sample_rate);
+ 
+-	last = !minstrel_ht_txstat_valid(mp, &ar[0]);
++	last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
+ 	for (i = 0; !last; i++) {
+ 		last = (i == IEEE80211_TX_MAX_RATES - 1) ||
+-		       !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
++		       !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
+ 
+ 		rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
+ 		if (rate == rate_sample)
+@@ -1031,7 +1099,7 @@ minstrel_calc_retransmit(struct minstrel
+ 	ctime += (t_slot * cw) >> 1;
+ 	cw = min((cw << 1) | 1, mp->cw_max);
+ 
+-	if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
++	if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES)) {
+ 		overhead = mi->overhead_legacy;
+ 		overhead_rtscts = mi->overhead_legacy_rtscts;
+ 	} else {
+@@ -1064,7 +1132,8 @@ static void
+ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
+                      struct ieee80211_sta_rates *ratetbl, int offset, int index)
+ {
+-	const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
++	int group_idx = index / MCS_GROUP_RATES;
++	const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
+ 	struct minstrel_rate_stats *mrs;
+ 	u8 idx;
+ 	u16 flags = group->flags;
+@@ -1083,13 +1152,17 @@ minstrel_ht_set_rate(struct minstrel_pri
+ 		ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
+ 	}
+ 
+-	if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
++	index %= MCS_GROUP_RATES;
++	if (group_idx == MINSTREL_CCK_GROUP)
+ 		idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
++	else if (group_idx == MINSTREL_OFDM_GROUP)
++		idx = mp->ofdm_rates[mi->band][index %
++					       ARRAY_SIZE(mp->ofdm_rates[0])];
+ 	else if (flags & IEEE80211_TX_RC_VHT_MCS)
+ 		idx = ((group->streams - 1) << 4) |
+-		      ((index % MCS_GROUP_RATES) & 0xF);
++		      (index & 0xF);
+ 	else
+-		idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
++		idx = index + (group->streams - 1) * 8;
+ 
+ 	/* enable RTS/CTS if needed:
+ 	 *  - if station is in dynamic SMPS (and streams > 1)
+@@ -1304,11 +1377,8 @@ minstrel_ht_get_rate(void *priv, struct
+ 	struct minstrel_priv *mp = priv;
+ 	int sample_idx;
+ 
+-	if (!msp->is_ht)
+-		return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
+-
+ 	if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
+-	    mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
++	    !minstrel_ht_is_legacy_group(mi->max_prob_rate / MCS_GROUP_RATES))
+ 		minstrel_aggr_check(sta, txrc->skb);
+ 
+ 	info->flags |= mi->tx_flags;
+@@ -1349,6 +1419,9 @@ minstrel_ht_get_rate(void *priv, struct
+ 	if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
+ 		int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
+ 		rate->idx = mp->cck_rates[idx];
++	} else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
++		int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
++		rate->idx = mp->ofdm_rates[mi->band][idx];
+ 	} else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
+ 		ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
+ 				       sample_group->streams);
+@@ -1369,11 +1442,13 @@ minstrel_ht_update_cck(struct minstrel_p
+ 	if (sband->band != NL80211_BAND_2GHZ)
+ 		return;
+ 
+-	if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
++	if (sta->ht_cap.ht_supported &&
++	    !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
+ 		return;
+ 
+ 	for (i = 0; i < 4; i++) {
+-		if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
++		if (mp->cck_rates[i] == 0xff ||
++		    !rate_supported(sta, sband->band, mp->cck_rates[i]))
+ 			continue;
+ 
+ 		mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
+@@ -1383,9 +1458,30 @@ minstrel_ht_update_cck(struct minstrel_p
+ }
+ 
+ static void
++minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
++			struct ieee80211_supported_band *sband,
++			struct ieee80211_sta *sta)
++{
++	const u8 *rates;
++	int i;
++
++	if (sta->ht_cap.ht_supported)
++		return;
++
++	rates = mp->ofdm_rates[sband->band];
++	for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
++		if (rates[i] == 0xff ||
++		    !rate_supported(sta, sband->band, rates[i]))
++			continue;
++
++		mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
++	}
++}
++
++static void
+ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
+ 			struct cfg80211_chan_def *chandef,
+-                        struct ieee80211_sta *sta, void *priv_sta)
++			struct ieee80211_sta *sta, void *priv_sta)
+ {
+ 	struct minstrel_priv *mp = priv;
+ 	struct minstrel_ht_sta_priv *msp = priv_sta;
+@@ -1401,10 +1497,6 @@ minstrel_ht_update_caps(void *priv, stru
+ 	int stbc;
+ 	int i;
+ 
+-	/* fall back to the old minstrel for legacy stations */
+-	if (!sta->ht_cap.ht_supported)
+-		goto use_legacy;
+-
+ 	BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
+ 
+ 	if (vht_cap->vht_supported)
+@@ -1412,10 +1504,10 @@ minstrel_ht_update_caps(void *priv, stru
+ 	else
+ 		use_vht = 0;
+ 
+-	msp->is_ht = true;
+ 	memset(mi, 0, sizeof(*mi));
+ 
+ 	mi->sta = sta;
++	mi->band = sband->band;
+ 	mi->last_stats_update = jiffies;
+ 
+ 	ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
+@@ -1464,10 +1556,8 @@ minstrel_ht_update_caps(void *priv, stru
+ 		int bw, nss;
+ 
+ 		mi->supported[i] = 0;
+-		if (i == MINSTREL_CCK_GROUP) {
+-			minstrel_ht_update_cck(mp, mi, sband, sta);
++		if (minstrel_ht_is_legacy_group(i))
+ 			continue;
+-		}
+ 
+ 		if (gflags & IEEE80211_TX_RC_SHORT_GI) {
+ 			if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
+@@ -1528,22 +1618,12 @@ minstrel_ht_update_caps(void *priv, stru
+ 			n_supported++;
+ 	}
+ 
+-	if (!n_supported)
+-		goto use_legacy;
++	minstrel_ht_update_cck(mp, mi, sband, sta);
++	minstrel_ht_update_ofdm(mp, mi, sband, sta);
+ 
+ 	/* create an initial rate table with the lowest supported rates */
+ 	minstrel_ht_update_stats(mp, mi, true);
+ 	minstrel_ht_update_rates(mp, mi);
+-
+-	return;
+-
+-use_legacy:
+-	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, chandef, sta,
+-					   &msp->legacy);
+ }
+ 
+ static void
+@@ -1611,40 +1691,70 @@ minstrel_ht_free_sta(void *priv, struct
+ }
+ 
+ static void
+-minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
++minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
++			    const s16 *bitrates, int n_rates, u32 rate_flags)
+ {
+-	static const int bitrates[4] = { 10, 20, 55, 110 };
+-	struct ieee80211_supported_band *sband;
+-	u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
+ 	int i, j;
+ 
+-	sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
+-	if (!sband)
+-		return;
+-
+ 	for (i = 0; i < sband->n_bitrates; i++) {
+ 		struct ieee80211_rate *rate = &sband->bitrates[i];
+ 
+-		if (rate->flags & IEEE80211_RATE_ERP_G)
+-			continue;
+-
+ 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
+ 			continue;
+ 
+-		for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
++		for (j = 0; j < n_rates; j++) {
+ 			if (rate->bitrate != bitrates[j])
+ 				continue;
+ 
+-			mp->cck_rates[j] = i;
++			dest[j] = i;
+ 			break;
+ 		}
+ 	}
+ }
+ 
++static void
++minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
++{
++	static const s16 bitrates[4] = { 10, 20, 55, 110 };
++	struct ieee80211_supported_band *sband;
++	u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
++
++	memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
++	sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
++	if (!sband)
++		return;
++
++	BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
++	minstrel_ht_fill_rate_array(mp->cck_rates, sband,
++				    minstrel_cck_bitrates,
++				    ARRAY_SIZE(minstrel_cck_bitrates),
++				    rate_flags);
++}
++
++static void
++minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
++{
++	static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
++	struct ieee80211_supported_band *sband;
++	u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
++
++	memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
++	sband = mp->hw->wiphy->bands[band];
++	if (!sband)
++		return;
++
++	BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
++	minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
++				    minstrel_ofdm_bitrates,
++				    ARRAY_SIZE(minstrel_ofdm_bitrates),
++				    rate_flags);
++}
++
+ static void *
+ minstrel_ht_alloc(struct ieee80211_hw *hw)
+ {
+ 	struct minstrel_priv *mp;
++	int i;
+ 
+ 	mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
+ 	if (!mp)
+@@ -1681,6 +1791,8 @@ minstrel_ht_alloc(struct ieee80211_hw *h
+ 	mp->new_avg = true;
+ 
+ 	minstrel_ht_init_cck_rates(mp);
++	for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
++	    minstrel_ht_init_ofdm_rates(mp, i);
+ 
+ 	return mp;
+ }
+@@ -1713,9 +1825,6 @@ static u32 minstrel_ht_get_expected_thro
+ 	struct minstrel_ht_sta *mi = &msp->ht;
+ 	int i, j, prob, tp_avg;
+ 
+-	if (!msp->is_ht)
+-		return mac80211_minstrel.get_expected_throughput(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_avg;
+--- a/net/mac80211/rc80211_minstrel_ht.h
++++ b/net/mac80211/rc80211_minstrel_ht.h
+@@ -18,14 +18,15 @@
+ 				 MINSTREL_HT_STREAM_GROUPS)
+ #define MINSTREL_VHT_GROUPS_NB	(MINSTREL_MAX_STREAMS *		\
+ 				 MINSTREL_VHT_STREAM_GROUPS)
+-#define MINSTREL_CCK_GROUPS_NB	1
++#define MINSTREL_LEGACY_GROUPS_NB	2
+ #define MINSTREL_GROUPS_NB	(MINSTREL_HT_GROUPS_NB +	\
+ 				 MINSTREL_VHT_GROUPS_NB +	\
+-				 MINSTREL_CCK_GROUPS_NB)
++				 MINSTREL_LEGACY_GROUPS_NB)
+ 
+ #define MINSTREL_HT_GROUP_0	0
+ #define MINSTREL_CCK_GROUP	(MINSTREL_HT_GROUP_0 + MINSTREL_HT_GROUPS_NB)
+-#define MINSTREL_VHT_GROUP_0	(MINSTREL_CCK_GROUP + 1)
++#define MINSTREL_OFDM_GROUP	(MINSTREL_CCK_GROUP + 1)
++#define MINSTREL_VHT_GROUP_0	(MINSTREL_OFDM_GROUP + 1)
+ 
+ #define MCS_GROUP_RATES		10
+ 
+@@ -37,6 +38,8 @@ struct mcs_group {
+ 	u16 duration[MCS_GROUP_RATES];
+ };
+ 
++extern const s16 minstrel_cck_bitrates[4];
++extern const s16 minstrel_ofdm_bitrates[8];
+ extern const struct mcs_group minstrel_mcs_groups[];
+ 
+ struct minstrel_mcs_group_data {
+@@ -99,6 +102,8 @@ struct minstrel_ht_sta {
+ 	/* current MCS group to be sampled */
+ 	u8 sample_group;
+ 
++	u8 band;
++
+ 	/* Bitfield of supported MCS rates of all groups */
+ 	u16 supported[MINSTREL_GROUPS_NB];
+ 
+@@ -107,13 +112,9 @@ struct minstrel_ht_sta {
+ };
+ 
+ struct minstrel_ht_sta_priv {
+-	union {
+-		struct minstrel_ht_sta ht;
+-		struct minstrel_sta_info legacy;
+-	};
++	struct minstrel_ht_sta ht;
+ 	void *ratelist;
+ 	void *sample_table;
+-	bool is_ht;
+ };
+ 
+ void minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
+--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
++++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
+@@ -52,7 +52,6 @@ minstrel_ht_stats_dump(struct minstrel_h
+ 
+ 	for (j = 0; j < MCS_GROUP_RATES; j++) {
+ 		struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j];
+-		static const int bitrates[4] = { 10, 20, 55, 110 };
+ 		int idx = i * MCS_GROUP_RATES + j;
+ 		unsigned int duration;
+ 
+@@ -67,6 +66,9 @@ minstrel_ht_stats_dump(struct minstrel_h
+ 			p += sprintf(p, "VHT%c0 ", htmode);
+ 			p += sprintf(p, "%cGI ", gimode);
+ 			p += sprintf(p, "%d  ", mg->streams);
++		} else if (i == MINSTREL_OFDM_GROUP) {
++			p += sprintf(p, "OFDM       ");
++			p += sprintf(p, "1 ");
+ 		} else {
+ 			p += sprintf(p, "CCK    ");
+ 			p += sprintf(p, "%cP  ", j < 4 ? 'L' : 'S');
+@@ -84,7 +86,12 @@ minstrel_ht_stats_dump(struct minstrel_h
+ 		} else if (gflags & IEEE80211_TX_RC_VHT_MCS) {
+ 			p += sprintf(p, "  MCS%-1u/%1u", j, mg->streams);
+ 		} else {
+-			int r = bitrates[j % 4];
++			int r;
++
++			if (i == MINSTREL_OFDM_GROUP)
++				r = minstrel_ofdm_bitrates[j % 8];
++			else
++				r = minstrel_cck_bitrates[j % 4];
+ 
+ 			p += sprintf(p, "   %2u.%1uM", r / 10, r % 10);
+ 		}
+@@ -124,16 +131,8 @@ minstrel_ht_stats_open(struct inode *ino
+ 	struct minstrel_ht_sta *mi = &msp->ht;
+ 	struct minstrel_debugfs_info *ms;
+ 	unsigned int i;
+-	int ret;
+ 	char *p;
+ 
+-	if (!msp->is_ht) {
+-		inode->i_private = &msp->legacy;
+-		ret = minstrel_stats_open(inode, file);
+-		inode->i_private = msp;
+-		return ret;
+-	}
+-
+ 	ms = kmalloc(32768, GFP_KERNEL);
+ 	if (!ms)
+ 		return -ENOMEM;
+@@ -199,7 +198,6 @@ minstrel_ht_stats_csv_dump(struct minstr
+ 
+ 	for (j = 0; j < MCS_GROUP_RATES; j++) {
+ 		struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j];
+-		static const int bitrates[4] = { 10, 20, 55, 110 };
+ 		int idx = i * MCS_GROUP_RATES + j;
+ 		unsigned int duration;
+ 
+@@ -214,6 +212,8 @@ minstrel_ht_stats_csv_dump(struct minstr
+ 			p += sprintf(p, "VHT%c0,", htmode);
+ 			p += sprintf(p, "%cGI,", gimode);
+ 			p += sprintf(p, "%d,", mg->streams);
++		} else if (i == MINSTREL_OFDM_GROUP) {
++			p += sprintf(p, "OFDM,,1,");
+ 		} else {
+ 			p += sprintf(p, "CCK,");
+ 			p += sprintf(p, "%cP,", j < 4 ? 'L' : 'S');
+@@ -231,7 +231,13 @@ minstrel_ht_stats_csv_dump(struct minstr
+ 		} else if (gflags & IEEE80211_TX_RC_VHT_MCS) {
+ 			p += sprintf(p, ",MCS%-1u/%1u,", j, mg->streams);
+ 		} else {
+-			int r = bitrates[j % 4];
++			int r;
++
++			if (i == MINSTREL_OFDM_GROUP)
++				r = minstrel_ofdm_bitrates[j % 8];
++			else
++				r = minstrel_cck_bitrates[j % 4];
++
+ 			p += sprintf(p, ",%2u.%1uM,", r / 10, r % 10);
+ 		}
+ 
+@@ -274,18 +280,9 @@ minstrel_ht_stats_csv_open(struct inode
+ 	struct minstrel_ht_sta *mi = &msp->ht;
+ 	struct minstrel_debugfs_info *ms;
+ 	unsigned int i;
+-	int ret;
+ 	char *p;
+ 
+-	if (!msp->is_ht) {
+-		inode->i_private = &msp->legacy;
+-		ret = minstrel_stats_csv_open(inode, file);
+-		inode->i_private = msp;
+-		return ret;
+-	}
+-
+ 	ms = kmalloc(32768, GFP_KERNEL);
+-
+ 	if (!ms)
+ 		return -ENOMEM;
+