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![Felix Fietkau](/assets/img/avatar_default.png)
Pass the rate selection table to mac80211 from minstrel_ht_update_stats. Only rates for sample attempts are set in info->control.rates. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
1059 lines
27 KiB
C
1059 lines
27 KiB
C
/*
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* Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/netdevice.h>
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#include <linux/types.h>
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#include <linux/skbuff.h>
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#include <linux/debugfs.h>
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#include <linux/random.h>
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#include <linux/ieee80211.h>
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#include <net/mac80211.h>
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#include "rate.h"
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#include "rc80211_minstrel.h"
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#include "rc80211_minstrel_ht.h"
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#define AVG_PKT_SIZE 1200
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/* Number of bits for an average sized packet */
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#define MCS_NBITS (AVG_PKT_SIZE << 3)
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/* Number of symbols for a packet with (bps) bits per symbol */
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#define MCS_NSYMS(bps) ((MCS_NBITS + (bps) - 1) / (bps))
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/* Transmission time (nanoseconds) for a packet containing (syms) symbols */
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#define MCS_SYMBOL_TIME(sgi, syms) \
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(sgi ? \
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((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
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((syms) * 1000) << 2 /* syms * 4 us */ \
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)
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/* Transmit duration for the raw data part of an average sized packet */
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#define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
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/*
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* Define group sort order: HT40 -> SGI -> #streams
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*/
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#define GROUP_IDX(_streams, _sgi, _ht40) \
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MINSTREL_MAX_STREAMS * 2 * _ht40 + \
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MINSTREL_MAX_STREAMS * _sgi + \
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_streams - 1
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/* MCS rate information for an MCS group */
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#define MCS_GROUP(_streams, _sgi, _ht40) \
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[GROUP_IDX(_streams, _sgi, _ht40)] = { \
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.streams = _streams, \
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.flags = \
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(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
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(_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
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.duration = { \
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MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
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MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
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MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
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MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
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MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
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MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
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MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
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MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
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} \
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}
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#define CCK_DURATION(_bitrate, _short, _len) \
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(1000 * (10 /* SIFS */ + \
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(_short ? 72 + 24 : 144 + 48 ) + \
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(8 * (_len + 4) * 10) / (_bitrate)))
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#define CCK_ACK_DURATION(_bitrate, _short) \
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(CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
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CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
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#define CCK_DURATION_LIST(_short) \
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CCK_ACK_DURATION(10, _short), \
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CCK_ACK_DURATION(20, _short), \
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CCK_ACK_DURATION(55, _short), \
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CCK_ACK_DURATION(110, _short)
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#define CCK_GROUP \
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[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS] = { \
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.streams = 0, \
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.duration = { \
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CCK_DURATION_LIST(false), \
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CCK_DURATION_LIST(true) \
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} \
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}
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/*
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* To enable sufficiently targeted rate sampling, MCS rates are divided into
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* groups, based on the number of streams and flags (HT40, SGI) that they
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* use.
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*
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* Sortorder has to be fixed for GROUP_IDX macro to be applicable:
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* HT40 -> SGI -> #streams
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*/
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const struct mcs_group minstrel_mcs_groups[] = {
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MCS_GROUP(1, 0, 0),
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MCS_GROUP(2, 0, 0),
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#if MINSTREL_MAX_STREAMS >= 3
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MCS_GROUP(3, 0, 0),
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#endif
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MCS_GROUP(1, 1, 0),
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MCS_GROUP(2, 1, 0),
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#if MINSTREL_MAX_STREAMS >= 3
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MCS_GROUP(3, 1, 0),
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#endif
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MCS_GROUP(1, 0, 1),
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MCS_GROUP(2, 0, 1),
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#if MINSTREL_MAX_STREAMS >= 3
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MCS_GROUP(3, 0, 1),
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#endif
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MCS_GROUP(1, 1, 1),
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MCS_GROUP(2, 1, 1),
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#if MINSTREL_MAX_STREAMS >= 3
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MCS_GROUP(3, 1, 1),
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#endif
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/* must be last */
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CCK_GROUP
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};
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#define MINSTREL_CCK_GROUP (ARRAY_SIZE(minstrel_mcs_groups) - 1)
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static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];
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static void
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minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
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/*
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* Look up an MCS group index based on mac80211 rate information
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*/
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static int
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minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
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{
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return GROUP_IDX((rate->idx / MCS_GROUP_RATES) + 1,
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!!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
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!!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
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}
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static struct minstrel_rate_stats *
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minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
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struct ieee80211_tx_rate *rate)
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{
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int group, idx;
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if (rate->flags & IEEE80211_TX_RC_MCS) {
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group = minstrel_ht_get_group_idx(rate);
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idx = rate->idx % MCS_GROUP_RATES;
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} else {
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group = MINSTREL_CCK_GROUP;
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for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
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if (rate->idx == mp->cck_rates[idx])
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break;
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/* short preamble */
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if (!(mi->groups[group].supported & BIT(idx)))
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idx += 4;
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}
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return &mi->groups[group].rates[idx];
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}
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static inline struct minstrel_rate_stats *
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minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
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{
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return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
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}
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/*
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* Recalculate success probabilities and counters for a rate using EWMA
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*/
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static void
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minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr)
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{
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if (unlikely(mr->attempts > 0)) {
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mr->sample_skipped = 0;
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mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
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if (!mr->att_hist)
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mr->probability = mr->cur_prob;
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else
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mr->probability = minstrel_ewma(mr->probability,
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mr->cur_prob, EWMA_LEVEL);
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mr->att_hist += mr->attempts;
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mr->succ_hist += mr->success;
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} else {
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mr->sample_skipped++;
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}
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mr->last_success = mr->success;
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mr->last_attempts = mr->attempts;
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mr->success = 0;
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mr->attempts = 0;
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}
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/*
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* Calculate throughput based on the average A-MPDU length, taking into account
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* the expected number of retransmissions and their expected length
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*/
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static void
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minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
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{
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struct minstrel_rate_stats *mr;
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unsigned int nsecs = 0;
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unsigned int tp;
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unsigned int prob;
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mr = &mi->groups[group].rates[rate];
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prob = mr->probability;
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if (prob < MINSTREL_FRAC(1, 10)) {
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mr->cur_tp = 0;
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return;
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}
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/*
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* For the throughput calculation, limit the probability value to 90% to
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* account for collision related packet error rate fluctuation
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*/
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if (prob > MINSTREL_FRAC(9, 10))
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prob = MINSTREL_FRAC(9, 10);
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if (group != MINSTREL_CCK_GROUP)
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nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
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nsecs += minstrel_mcs_groups[group].duration[rate];
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tp = 1000000 * ((mr->probability * 1000) / nsecs);
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mr->cur_tp = MINSTREL_TRUNC(tp);
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}
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/*
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* Update rate statistics and select new primary rates
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*
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* Rules for rate selection:
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* - max_prob_rate must use only one stream, as a tradeoff between delivery
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* probability and throughput during strong fluctuations
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* - as long as the max prob rate has a probability of more than 3/4, pick
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* higher throughput rates, even if the probablity is a bit lower
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*/
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static void
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minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
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{
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struct minstrel_mcs_group_data *mg;
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struct minstrel_rate_stats *mr;
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int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
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int group, i, index;
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bool mi_rates_valid = false;
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if (mi->ampdu_packets > 0) {
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mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
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MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
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mi->ampdu_len = 0;
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mi->ampdu_packets = 0;
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}
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mi->sample_slow = 0;
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mi->sample_count = 0;
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for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
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bool mg_rates_valid = false;
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cur_prob = 0;
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cur_prob_tp = 0;
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cur_tp = 0;
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cur_tp2 = 0;
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mg = &mi->groups[group];
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if (!mg->supported)
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continue;
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mi->sample_count++;
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for (i = 0; i < MCS_GROUP_RATES; i++) {
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if (!(mg->supported & BIT(i)))
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continue;
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/* initialize rates selections starting indexes */
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if (!mg_rates_valid) {
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mg->max_tp_rate = mg->max_tp_rate2 =
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mg->max_prob_rate = i;
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if (!mi_rates_valid) {
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mi->max_tp_rate = mi->max_tp_rate2 =
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mi->max_prob_rate = i;
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mi_rates_valid = true;
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}
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mg_rates_valid = true;
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}
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mr = &mg->rates[i];
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mr->retry_updated = false;
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index = MCS_GROUP_RATES * group + i;
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minstrel_calc_rate_ewma(mr);
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minstrel_ht_calc_tp(mi, group, i);
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if (!mr->cur_tp)
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continue;
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if ((mr->cur_tp > cur_prob_tp && mr->probability >
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MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
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mg->max_prob_rate = index;
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cur_prob = mr->probability;
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cur_prob_tp = mr->cur_tp;
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}
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if (mr->cur_tp > cur_tp) {
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swap(index, mg->max_tp_rate);
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cur_tp = mr->cur_tp;
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mr = minstrel_get_ratestats(mi, index);
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}
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if (index >= mg->max_tp_rate)
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continue;
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if (mr->cur_tp > cur_tp2) {
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mg->max_tp_rate2 = index;
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cur_tp2 = mr->cur_tp;
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}
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}
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}
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/* try to sample all available rates during each interval */
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mi->sample_count *= 8;
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cur_prob = 0;
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cur_prob_tp = 0;
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cur_tp = 0;
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cur_tp2 = 0;
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for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
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mg = &mi->groups[group];
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if (!mg->supported)
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continue;
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mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
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if (cur_tp < mr->cur_tp) {
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mi->max_tp_rate2 = mi->max_tp_rate;
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cur_tp2 = cur_tp;
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mi->max_tp_rate = mg->max_tp_rate;
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cur_tp = mr->cur_tp;
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mi->max_prob_streams = minstrel_mcs_groups[group].streams - 1;
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}
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mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
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if (cur_tp2 < mr->cur_tp) {
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mi->max_tp_rate2 = mg->max_tp_rate2;
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cur_tp2 = mr->cur_tp;
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}
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}
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if (mi->max_prob_streams < 1)
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mi->max_prob_streams = 1;
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for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
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mg = &mi->groups[group];
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if (!mg->supported)
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continue;
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mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
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if (cur_prob_tp < mr->cur_tp &&
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minstrel_mcs_groups[group].streams <= mi->max_prob_streams) {
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mi->max_prob_rate = mg->max_prob_rate;
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cur_prob = mr->cur_prob;
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cur_prob_tp = mr->cur_tp;
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}
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}
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mi->stats_update = jiffies;
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}
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static bool
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minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
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{
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if (rate->idx < 0)
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return false;
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if (!rate->count)
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return false;
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if (rate->flags & IEEE80211_TX_RC_MCS)
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return true;
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return rate->idx == mp->cck_rates[0] ||
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rate->idx == mp->cck_rates[1] ||
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rate->idx == mp->cck_rates[2] ||
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rate->idx == mp->cck_rates[3];
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}
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static void
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minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
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{
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struct minstrel_mcs_group_data *mg;
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for (;;) {
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mi->sample_group++;
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mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
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mg = &mi->groups[mi->sample_group];
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if (!mg->supported)
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continue;
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if (++mg->index >= MCS_GROUP_RATES) {
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mg->index = 0;
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if (++mg->column >= ARRAY_SIZE(sample_table))
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mg->column = 0;
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}
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break;
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}
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}
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static void
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minstrel_downgrade_rate(struct minstrel_ht_sta *mi, unsigned int *idx,
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bool primary)
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{
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int group, orig_group;
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orig_group = group = *idx / MCS_GROUP_RATES;
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while (group > 0) {
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group--;
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if (!mi->groups[group].supported)
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continue;
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if (minstrel_mcs_groups[group].streams >
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minstrel_mcs_groups[orig_group].streams)
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continue;
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if (primary)
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*idx = mi->groups[group].max_tp_rate;
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else
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*idx = mi->groups[group].max_tp_rate2;
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break;
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}
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}
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static void
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minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
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{
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struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
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struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
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u16 tid;
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if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
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return;
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if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
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return;
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tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
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if (likely(sta->ampdu_mlme.tid_tx[tid]))
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return;
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if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
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return;
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ieee80211_start_tx_ba_session(pubsta, tid, 5000);
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}
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static void
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minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
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struct ieee80211_sta *sta, void *priv_sta,
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struct sk_buff *skb)
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{
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struct minstrel_ht_sta_priv *msp = priv_sta;
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struct minstrel_ht_sta *mi = &msp->ht;
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struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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struct ieee80211_tx_rate *ar = info->status.rates;
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struct minstrel_rate_stats *rate, *rate2;
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struct minstrel_priv *mp = priv;
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bool last, update = false;
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int i;
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if (!msp->is_ht)
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return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
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/* This packet was aggregated but doesn't carry status info */
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if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
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!(info->flags & IEEE80211_TX_STAT_AMPDU))
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return;
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|
|
if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
|
|
info->status.ampdu_ack_len =
|
|
(info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
|
|
info->status.ampdu_len = 1;
|
|
}
|
|
|
|
mi->ampdu_packets++;
|
|
mi->ampdu_len += info->status.ampdu_len;
|
|
|
|
if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
|
|
mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
|
|
mi->sample_tries = 1;
|
|
mi->sample_count--;
|
|
}
|
|
|
|
if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
|
|
mi->sample_packets += info->status.ampdu_len;
|
|
|
|
last = !minstrel_ht_txstat_valid(mp, &ar[0]);
|
|
for (i = 0; !last; i++) {
|
|
last = (i == IEEE80211_TX_MAX_RATES - 1) ||
|
|
!minstrel_ht_txstat_valid(mp, &ar[i + 1]);
|
|
|
|
rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
|
|
|
|
if (last)
|
|
rate->success += info->status.ampdu_ack_len;
|
|
|
|
rate->attempts += ar[i].count * info->status.ampdu_len;
|
|
}
|
|
|
|
/*
|
|
* 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 (rate->attempts > 30 &&
|
|
MINSTREL_FRAC(rate->success, rate->attempts) <
|
|
MINSTREL_FRAC(20, 100)) {
|
|
minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
|
|
update = true;
|
|
}
|
|
|
|
rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
|
|
if (rate2->attempts > 30 &&
|
|
MINSTREL_FRAC(rate2->success, rate2->attempts) <
|
|
MINSTREL_FRAC(20, 100)) {
|
|
minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
|
|
update = true;
|
|
}
|
|
|
|
if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
|
|
update = true;
|
|
minstrel_ht_update_stats(mp, mi);
|
|
if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
|
|
mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
|
|
minstrel_aggr_check(sta, skb);
|
|
}
|
|
|
|
if (update)
|
|
minstrel_ht_update_rates(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 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)) {
|
|
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 / 1000;
|
|
|
|
/* Contention time for first 2 tries */
|
|
ctime = (t_slot * cw) >> 1;
|
|
cw = min((cw << 1) | 1, mp->cw_max);
|
|
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 * (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 {
|
|
/* Contention time for this try */
|
|
ctime = (t_slot * cw) >> 1;
|
|
cw = min((cw << 1) | 1, mp->cw_max);
|
|
|
|
/* Total TX time after this try */
|
|
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++;
|
|
} 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_sta_rates *ratetbl, int offset, int index)
|
|
{
|
|
const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
|
|
struct minstrel_rate_stats *mr;
|
|
u8 idx;
|
|
u16 flags;
|
|
|
|
mr = minstrel_get_ratestats(mi, index);
|
|
if (!mr->retry_updated)
|
|
minstrel_calc_retransmit(mp, mi, index);
|
|
|
|
if (mr->probability < MINSTREL_FRAC(20, 100) || !mr->retry_count) {
|
|
ratetbl->rate[offset].count = 2;
|
|
ratetbl->rate[offset].count_rts = 2;
|
|
ratetbl->rate[offset].count_cts = 2;
|
|
} else {
|
|
ratetbl->rate[offset].count = mr->retry_count;
|
|
ratetbl->rate[offset].count_cts = mr->retry_count;
|
|
ratetbl->rate[offset].count_rts = mr->retry_count_rtscts;
|
|
}
|
|
|
|
if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
|
|
idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
|
|
flags = 0;
|
|
} else {
|
|
idx = index % MCS_GROUP_RATES +
|
|
(group->streams - 1) * MCS_GROUP_RATES;
|
|
flags = IEEE80211_TX_RC_MCS | group->flags;
|
|
}
|
|
|
|
if (offset > 0) {
|
|
ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
|
|
flags |= IEEE80211_TX_RC_USE_RTS_CTS;
|
|
}
|
|
|
|
ratetbl->rate[offset].idx = idx;
|
|
ratetbl->rate[offset].flags = flags;
|
|
}
|
|
|
|
static void
|
|
minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
|
|
{
|
|
struct ieee80211_sta_rates *rates;
|
|
int i = 0;
|
|
|
|
rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
|
|
if (!rates)
|
|
return;
|
|
|
|
/* Start with max_tp_rate */
|
|
minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate);
|
|
|
|
if (mp->hw->max_rates >= 3) {
|
|
/* At least 3 tx rates supported, use max_tp_rate2 next */
|
|
minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate2);
|
|
}
|
|
|
|
if (mp->hw->max_rates >= 2) {
|
|
/*
|
|
* At least 2 tx rates supported, use max_prob_rate next */
|
|
minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
|
|
}
|
|
|
|
rates->rate[i].idx = -1;
|
|
rate_control_set_rates(mp->hw, mi->sta, 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)
|
|
{
|
|
struct minstrel_rate_stats *mr;
|
|
struct minstrel_mcs_group_data *mg;
|
|
unsigned int sample_dur, sample_group;
|
|
int sample_idx = 0;
|
|
|
|
if (mi->sample_wait > 0) {
|
|
mi->sample_wait--;
|
|
return -1;
|
|
}
|
|
|
|
if (!mi->sample_tries)
|
|
return -1;
|
|
|
|
mg = &mi->groups[mi->sample_group];
|
|
sample_idx = sample_table[mg->column][mg->index];
|
|
mr = &mg->rates[sample_idx];
|
|
sample_group = mi->sample_group;
|
|
sample_idx += sample_group * MCS_GROUP_RATES;
|
|
minstrel_next_sample_idx(mi);
|
|
|
|
/*
|
|
* Sampling might add some overhead (RTS, no aggregation)
|
|
* to the frame. Hence, don't use sampling for the currently
|
|
* used rates.
|
|
*/
|
|
if (sample_idx == mi->max_tp_rate ||
|
|
sample_idx == mi->max_tp_rate2 ||
|
|
sample_idx == mi->max_prob_rate)
|
|
return -1;
|
|
|
|
/*
|
|
* Do not sample if the probability is already higher than 95%
|
|
* to avoid wasting airtime.
|
|
*/
|
|
if (mr->probability > MINSTREL_FRAC(95, 100))
|
|
return -1;
|
|
|
|
/*
|
|
* Make sure that lower rates get sampled only occasionally,
|
|
* if the link is working perfectly.
|
|
*/
|
|
sample_dur = minstrel_get_duration(sample_idx);
|
|
if (sample_dur >= minstrel_get_duration(mi->max_tp_rate2) &&
|
|
(mi->max_prob_streams <
|
|
minstrel_mcs_groups[sample_group].streams ||
|
|
sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
|
|
if (mr->sample_skipped < 20)
|
|
return -1;
|
|
|
|
if (mi->sample_slow++ > 2)
|
|
return -1;
|
|
}
|
|
mi->sample_tries--;
|
|
|
|
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)
|
|
{
|
|
const struct mcs_group *sample_group;
|
|
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
|
|
struct ieee80211_tx_rate *rate = &info->status.rates[0];
|
|
struct minstrel_ht_sta_priv *msp = priv_sta;
|
|
struct minstrel_ht_sta *mi = &msp->ht;
|
|
struct minstrel_priv *mp = priv;
|
|
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);
|
|
|
|
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 &&
|
|
txrc->skb->protocol == cpu_to_be16(ETH_P_PAE))
|
|
sample_idx = -1;
|
|
else
|
|
sample_idx = minstrel_get_sample_rate(mp, mi);
|
|
|
|
#ifdef CONFIG_MAC80211_DEBUGFS
|
|
/* use fixed index if set */
|
|
if (mp->fixed_rate_idx != -1) {
|
|
mi->max_tp_rate = mp->fixed_rate_idx;
|
|
mi->max_tp_rate2 = mp->fixed_rate_idx;
|
|
mi->max_prob_rate = mp->fixed_rate_idx;
|
|
sample_idx = -1;
|
|
}
|
|
#endif
|
|
|
|
mi->total_packets++;
|
|
|
|
/* wraparound */
|
|
if (mi->total_packets == ~0) {
|
|
mi->total_packets = 0;
|
|
mi->sample_packets = 0;
|
|
}
|
|
|
|
if (sample_idx < 0)
|
|
return;
|
|
|
|
sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
|
|
info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
|
|
rate->idx = sample_idx % MCS_GROUP_RATES +
|
|
(sample_group->streams - 1) * MCS_GROUP_RATES;
|
|
rate->flags = IEEE80211_TX_RC_MCS | sample_group->flags;
|
|
rate->count = 1;
|
|
}
|
|
|
|
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)
|
|
{
|
|
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;
|
|
u16 sta_cap = sta->ht_cap.cap;
|
|
int n_supported = 0;
|
|
int ack_dur;
|
|
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_MAX_STREAMS * MINSTREL_STREAM_GROUPS + 1);
|
|
|
|
msp->is_ht = true;
|
|
memset(mi, 0, sizeof(*mi));
|
|
|
|
mi->sta = sta;
|
|
mi->stats_update = jiffies;
|
|
|
|
ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1);
|
|
mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1) + ack_dur;
|
|
mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
|
|
|
|
mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
|
|
|
|
/* When using MRR, sample more on the first attempt, without delay */
|
|
if (mp->has_mrr) {
|
|
mi->sample_count = 16;
|
|
mi->sample_wait = 0;
|
|
} else {
|
|
mi->sample_count = 8;
|
|
mi->sample_wait = 8;
|
|
}
|
|
mi->sample_tries = 4;
|
|
|
|
stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
|
|
IEEE80211_HT_CAP_RX_STBC_SHIFT;
|
|
mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
|
|
|
|
if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
|
|
mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
|
|
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) {
|
|
if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
|
|
continue;
|
|
} else {
|
|
if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
|
|
sta->bandwidth < IEEE80211_STA_RX_BW_40)
|
|
continue;
|
|
|
|
/* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
|
|
if (sta->smps_mode == IEEE80211_SMPS_STATIC &&
|
|
minstrel_mcs_groups[i].streams > 1)
|
|
continue;
|
|
|
|
mi->groups[i].supported =
|
|
mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
|
|
|
|
if (mi->groups[i].supported)
|
|
n_supported++;
|
|
}
|
|
|
|
if (!n_supported)
|
|
goto use_legacy;
|
|
|
|
/* create an initial rate table with the lowest supported rates */
|
|
minstrel_ht_update_stats(mp, mi);
|
|
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, sta, &msp->legacy);
|
|
}
|
|
|
|
static void
|
|
minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
|
|
struct ieee80211_sta *sta, void *priv_sta)
|
|
{
|
|
minstrel_ht_update_caps(priv, sband, sta, priv_sta);
|
|
}
|
|
|
|
static void
|
|
minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
|
|
struct ieee80211_sta *sta, void *priv_sta,
|
|
u32 changed)
|
|
{
|
|
minstrel_ht_update_caps(priv, sband, sta, priv_sta);
|
|
}
|
|
|
|
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(*msp), 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->ratelist);
|
|
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,
|
|
.rate_update = minstrel_ht_rate_update,
|
|
.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);
|
|
}
|