From a0497f9f57478c5a37c5628eb32833dd9729a821 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Wed, 13 Feb 2013 10:51:08 +0100 Subject: mac80211/minstrel_ht: add support for using CCK rates When MCS rates start to get bad in 2.4 GHz because of long range or strong interference, CCK rates can be a lot more robust. This patch adds a pseudo MCS group containing CCK rates (long preamble in the lower 4 slots, short preamble in the upper slots). Signed-off-by: Felix Fietkau [make minstrel_ht_get_stats static] Signed-off-by: Johannes Berg --- net/mac80211/rc80211_minstrel_ht.c | 152 ++++++++++++++++++++++++++++++++----- 1 file changed, 135 insertions(+), 17 deletions(-) (limited to 'net/mac80211/rc80211_minstrel_ht.c') diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 5bb316aff21a..6e35dcd2aa2f 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2010 Felix Fietkau + * Copyright (C) 2010-2013 Felix Fietkau * * 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 @@ -63,6 +63,30 @@ } \ } +#define CCK_DURATION(_bitrate, _short, _len) \ + (10 /* SIFS */ + \ + (_short ? 72 + 24 : 144 + 48 ) + \ + (8 * (_len + 4) * 10) / (_bitrate)) + +#define CCK_ACK_DURATION(_bitrate, _short) \ + (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ + CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) + +#define CCK_DURATION_LIST(_short) \ + CCK_ACK_DURATION(10, _short), \ + CCK_ACK_DURATION(20, _short), \ + CCK_ACK_DURATION(55, _short), \ + CCK_ACK_DURATION(110, _short) + +#define CCK_GROUP \ + [MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS] = { \ + .streams = 0, \ + .duration = { \ + CCK_DURATION_LIST(false), \ + CCK_DURATION_LIST(true) \ + } \ + } + /* * To enable sufficiently targeted rate sampling, MCS rates are divided into * groups, based on the number of streams and flags (HT40, SGI) that they @@ -95,8 +119,13 @@ const struct mcs_group minstrel_mcs_groups[] = { #if MINSTREL_MAX_STREAMS >= 3 MCS_GROUP(3, 1, 1), #endif + + /* must be last */ + CCK_GROUP }; +#define MINSTREL_CCK_GROUP (ARRAY_SIZE(minstrel_mcs_groups) - 1) + static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES]; /* @@ -119,6 +148,29 @@ minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); } +static struct minstrel_rate_stats * +minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, + struct ieee80211_tx_rate *rate) +{ + int group, idx; + + if (rate->flags & IEEE80211_TX_RC_MCS) { + group = minstrel_ht_get_group_idx(rate); + idx = rate->idx % MCS_GROUP_RATES; + } else { + group = MINSTREL_CCK_GROUP; + + for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) + if (rate->idx == mp->cck_rates[idx]) + break; + + /* short preamble */ + if (!(mi->groups[group].supported & BIT(idx))) + idx += 4; + } + return &mi->groups[group].rates[idx]; +} + static inline struct minstrel_rate_stats * minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) { @@ -159,7 +211,7 @@ static void minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate) { struct minstrel_rate_stats *mr; - unsigned int usecs; + unsigned int usecs = 0; mr = &mi->groups[group].rates[rate]; @@ -168,7 +220,9 @@ minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate) return; } - usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len); + if (group != MINSTREL_CCK_GROUP) + 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); } @@ -293,7 +347,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) } static bool -minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate) +minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) { if (rate->idx < 0) return false; @@ -301,7 +355,13 @@ minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate) if (!rate->count) return false; - return !!(rate->flags & IEEE80211_TX_RC_MCS); + if (rate->flags & IEEE80211_TX_RC_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]; } static void @@ -386,7 +446,6 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, struct minstrel_rate_stats *rate, *rate2; struct minstrel_priv *mp = priv; bool last; - int group; int i; if (!msp->is_ht) @@ -415,13 +474,12 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) mi->sample_packets += info->status.ampdu_len; - last = !minstrel_ht_txstat_valid(&ar[0]); + last = !minstrel_ht_txstat_valid(mp, &ar[0]); for (i = 0; !last; i++) { last = (i == IEEE80211_TX_MAX_RATES - 1) || - !minstrel_ht_txstat_valid(&ar[i + 1]); + !minstrel_ht_txstat_valid(mp, &ar[i + 1]); - group = minstrel_ht_get_group_idx(&ar[i]); - rate = &mi->groups[group].rates[ar[i].idx % 8]; + rate = minstrel_ht_get_stats(mp, mi, &ar[i]); if (last) rate->success += info->status.ampdu_ack_len; @@ -447,7 +505,8 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) { minstrel_ht_update_stats(mp, mi); - if (!(info->flags & IEEE80211_TX_CTL_AMPDU)) + if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && + mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) minstrel_aggr_check(sta, skb); } } @@ -463,6 +522,7 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, unsigned int ctime = 0; unsigned int t_slot = 9; /* FIXME */ unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len); + unsigned int overhead = 0, overhead_rtscts = 0; mr = minstrel_get_ratestats(mi, index); if (mr->probability < MINSTREL_FRAC(1, 10)) { @@ -484,9 +544,14 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, ctime += (t_slot * cw) >> 1; cw = min((cw << 1) | 1, mp->cw_max); + if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { + overhead = mi->overhead; + overhead_rtscts = mi->overhead_rtscts; + } + /* Total TX time for data and Contention after first 2 tries */ - tx_time = ctime + 2 * (mi->overhead + tx_time_data); - tx_time_rtscts = ctime + 2 * (mi->overhead_rtscts + tx_time_data); + tx_time = ctime + 2 * (overhead + tx_time_data); + tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); /* See how many more tries we can fit inside segment size */ do { @@ -495,8 +560,8 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, cw = min((cw << 1) | 1, mp->cw_max); /* Total TX time after this try */ - tx_time += ctime + mi->overhead + tx_time_data; - tx_time_rtscts += ctime + mi->overhead_rtscts + tx_time_data; + tx_time += ctime + overhead + tx_time_data; + tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; if (tx_time_rtscts < mp->segment_size) mr->retry_count_rtscts++; @@ -526,9 +591,16 @@ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, else rate->count = mr->retry_count; - rate->flags = IEEE80211_TX_RC_MCS | group->flags; + rate->flags = 0; if (rtscts) rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS; + + if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) { + rate->idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; + return; + } + + rate->flags |= IEEE80211_TX_RC_MCS | group->flags; rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES; } @@ -591,6 +663,22 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) return sample_idx; } +static void +minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp, + struct minstrel_ht_sta *mi, bool val) +{ + u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported; + + if (!supported || !mi->cck_supported_short) + return; + + if (supported & (mi->cck_supported_short << (val * 4))) + return; + + supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4); + mi->groups[MINSTREL_CCK_GROUP].supported = supported; +} + static void minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, struct ieee80211_tx_rate_control *txrc) @@ -610,6 +698,7 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); info->flags |= mi->tx_flags; + minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble); /* Don't use EAPOL frames for sampling on non-mrr hw */ if (mp->hw->max_rates == 1 && @@ -682,6 +771,30 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, } } +static void +minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, + struct ieee80211_supported_band *sband, + struct ieee80211_sta *sta) +{ + int i; + + if (sband->band != IEEE80211_BAND_2GHZ) + return; + + mi->cck_supported = 0; + mi->cck_supported_short = 0; + for (i = 0; i < 4; i++) { + if (!rate_supported(sta, sband->band, mp->cck_rates[i])) + continue; + + mi->cck_supported |= BIT(i); + if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) + mi->cck_supported_short |= BIT(i); + } + + mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported; +} + static void minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, struct ieee80211_sta *sta, void *priv_sta) @@ -702,7 +815,7 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, goto use_legacy; BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != - MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS); + MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS + 1); msp->is_ht = true; memset(mi, 0, sizeof(*mi)); @@ -738,6 +851,11 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, u16 req = 0; mi->groups[i].supported = 0; + if (i == MINSTREL_CCK_GROUP) { + minstrel_ht_update_cck(mp, mi, sband, sta); + continue; + } + 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; -- cgit v1.2.3