2 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 #include <linux/netdevice.h>
9 #include <linux/types.h>
10 #include <linux/skbuff.h>
11 #include <linux/debugfs.h>
12 #include <linux/random.h>
13 #include <linux/moduleparam.h>
14 #include <linux/ieee80211.h>
15 #include <net/mac80211.h>
18 #include "rc80211_minstrel.h"
19 #include "rc80211_minstrel_ht.h"
21 #define AVG_AMPDU_SIZE 16
22 #define AVG_PKT_SIZE 1200
24 /* Number of bits for an average sized packet */
25 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
27 /* Number of symbols for a packet with (bps) bits per symbol */
28 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
30 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
31 #define MCS_SYMBOL_TIME(sgi, syms) \
33 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
34 ((syms) * 1000) << 2 /* syms * 4 us */ \
37 /* Transmit duration for the raw data part of an average sized packet */
38 #define MCS_DURATION(streams, sgi, bps) \
39 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
46 * Define group sort order: HT40 -> SGI -> #streams
48 #define GROUP_IDX(_streams, _sgi, _ht40) \
49 MINSTREL_HT_GROUP_0 + \
50 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
51 MINSTREL_MAX_STREAMS * _sgi + \
54 /* MCS rate information for an MCS group */
55 #define MCS_GROUP(_streams, _sgi, _ht40) \
56 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
57 .streams = _streams, \
59 IEEE80211_TX_RC_MCS | \
60 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
61 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
63 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
64 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
65 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
68 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
74 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
75 (MINSTREL_VHT_GROUP_0 + \
76 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
77 MINSTREL_MAX_STREAMS * (_sgi) + \
80 #define BW2VBPS(_bw, r3, r2, r1) \
81 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
83 #define VHT_GROUP(_streams, _sgi, _bw) \
84 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
85 .streams = _streams, \
87 IEEE80211_TX_RC_VHT_MCS | \
88 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
89 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
90 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
92 MCS_DURATION(_streams, _sgi, \
93 BW2VBPS(_bw, 117, 54, 26)), \
94 MCS_DURATION(_streams, _sgi, \
95 BW2VBPS(_bw, 234, 108, 52)), \
96 MCS_DURATION(_streams, _sgi, \
97 BW2VBPS(_bw, 351, 162, 78)), \
98 MCS_DURATION(_streams, _sgi, \
99 BW2VBPS(_bw, 468, 216, 104)), \
100 MCS_DURATION(_streams, _sgi, \
101 BW2VBPS(_bw, 702, 324, 156)), \
102 MCS_DURATION(_streams, _sgi, \
103 BW2VBPS(_bw, 936, 432, 208)), \
104 MCS_DURATION(_streams, _sgi, \
105 BW2VBPS(_bw, 1053, 486, 234)), \
106 MCS_DURATION(_streams, _sgi, \
107 BW2VBPS(_bw, 1170, 540, 260)), \
108 MCS_DURATION(_streams, _sgi, \
109 BW2VBPS(_bw, 1404, 648, 312)), \
110 MCS_DURATION(_streams, _sgi, \
111 BW2VBPS(_bw, 1560, 720, 346)) \
115 #define CCK_DURATION(_bitrate, _short, _len) \
116 (1000 * (10 /* SIFS */ + \
117 (_short ? 72 + 24 : 144 + 48) + \
118 (8 * (_len + 4) * 10) / (_bitrate)))
120 #define CCK_ACK_DURATION(_bitrate, _short) \
121 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
122 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
124 #define CCK_DURATION_LIST(_short) \
125 CCK_ACK_DURATION(10, _short), \
126 CCK_ACK_DURATION(20, _short), \
127 CCK_ACK_DURATION(55, _short), \
128 CCK_ACK_DURATION(110, _short)
131 [MINSTREL_CCK_GROUP] = { \
135 CCK_DURATION_LIST(false), \
136 CCK_DURATION_LIST(true) \
140 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
141 static bool minstrel_vht_only = true;
142 module_param(minstrel_vht_only, bool, 0644);
143 MODULE_PARM_DESC(minstrel_vht_only,
144 "Use only VHT rates when VHT is supported by sta.");
148 * To enable sufficiently targeted rate sampling, MCS rates are divided into
149 * groups, based on the number of streams and flags (HT40, SGI) that they
152 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
153 * BW -> SGI -> #streams
155 const struct mcs_group minstrel_mcs_groups[] = {
156 MCS_GROUP(1, 0, BW_20),
157 MCS_GROUP(2, 0, BW_20),
158 #if MINSTREL_MAX_STREAMS >= 3
159 MCS_GROUP(3, 0, BW_20),
162 MCS_GROUP(1, 1, BW_20),
163 MCS_GROUP(2, 1, BW_20),
164 #if MINSTREL_MAX_STREAMS >= 3
165 MCS_GROUP(3, 1, BW_20),
168 MCS_GROUP(1, 0, BW_40),
169 MCS_GROUP(2, 0, BW_40),
170 #if MINSTREL_MAX_STREAMS >= 3
171 MCS_GROUP(3, 0, BW_40),
174 MCS_GROUP(1, 1, BW_40),
175 MCS_GROUP(2, 1, BW_40),
176 #if MINSTREL_MAX_STREAMS >= 3
177 MCS_GROUP(3, 1, BW_40),
182 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
183 VHT_GROUP(1, 0, BW_20),
184 VHT_GROUP(2, 0, BW_20),
185 #if MINSTREL_MAX_STREAMS >= 3
186 VHT_GROUP(3, 0, BW_20),
189 VHT_GROUP(1, 1, BW_20),
190 VHT_GROUP(2, 1, BW_20),
191 #if MINSTREL_MAX_STREAMS >= 3
192 VHT_GROUP(3, 1, BW_20),
195 VHT_GROUP(1, 0, BW_40),
196 VHT_GROUP(2, 0, BW_40),
197 #if MINSTREL_MAX_STREAMS >= 3
198 VHT_GROUP(3, 0, BW_40),
201 VHT_GROUP(1, 1, BW_40),
202 VHT_GROUP(2, 1, BW_40),
203 #if MINSTREL_MAX_STREAMS >= 3
204 VHT_GROUP(3, 1, BW_40),
207 VHT_GROUP(1, 0, BW_80),
208 VHT_GROUP(2, 0, BW_80),
209 #if MINSTREL_MAX_STREAMS >= 3
210 VHT_GROUP(3, 0, BW_80),
213 VHT_GROUP(1, 1, BW_80),
214 VHT_GROUP(2, 1, BW_80),
215 #if MINSTREL_MAX_STREAMS >= 3
216 VHT_GROUP(3, 1, BW_80),
221 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
224 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
227 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
228 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
230 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
233 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
238 if (nss != 3 && nss != 6)
240 } else if (bw == BW_80) {
241 if (nss == 3 || nss == 7)
246 WARN_ON(bw != BW_40);
249 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
250 case IEEE80211_VHT_MCS_SUPPORT_0_7:
253 case IEEE80211_VHT_MCS_SUPPORT_0_8:
256 case IEEE80211_VHT_MCS_SUPPORT_0_9:
262 return 0x3ff & ~mask;
266 * Look up an MCS group index based on mac80211 rate information
269 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
271 return GROUP_IDX((rate->idx / 8) + 1,
272 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
273 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
277 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
279 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
280 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
281 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
282 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
285 static struct minstrel_rate_stats *
286 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
287 struct ieee80211_tx_rate *rate)
291 if (rate->flags & IEEE80211_TX_RC_MCS) {
292 group = minstrel_ht_get_group_idx(rate);
294 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
295 group = minstrel_vht_get_group_idx(rate);
296 idx = ieee80211_rate_get_vht_mcs(rate);
298 group = MINSTREL_CCK_GROUP;
300 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
301 if (rate->idx == mp->cck_rates[idx])
305 if (!(mi->supported[group] & BIT(idx)))
308 return &mi->groups[group].rates[idx];
311 static inline struct minstrel_rate_stats *
312 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
314 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
318 * Return current throughput based on the average A-MPDU length, taking into
319 * account the expected number of retransmissions and their expected length
322 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
325 unsigned int nsecs = 0;
327 /* do not account throughput if sucess prob is below 10% */
328 if (prob_ewma < MINSTREL_FRAC(10, 100))
331 if (group != MINSTREL_CCK_GROUP)
332 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
334 nsecs += minstrel_mcs_groups[group].duration[rate];
337 * For the throughput calculation, limit the probability value to 90% to
338 * account for collision related packet error rate fluctuation
339 * (prob is scaled - see MINSTREL_FRAC above)
341 if (prob_ewma > MINSTREL_FRAC(90, 100))
342 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
345 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
349 * Find & sort topmost throughput rates
351 * If multiple rates provide equal throughput the sorting is based on their
352 * current success probability. Higher success probability is preferred among
353 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
356 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
359 int cur_group, cur_idx, cur_tp_avg, cur_prob;
360 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
361 int j = MAX_THR_RATES;
363 cur_group = index / MCS_GROUP_RATES;
364 cur_idx = index % MCS_GROUP_RATES;
365 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
366 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
369 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
370 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
371 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
372 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
374 if (cur_tp_avg < tmp_tp_avg ||
375 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
380 if (j < MAX_THR_RATES - 1) {
381 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
382 (MAX_THR_RATES - (j + 1))));
384 if (j < MAX_THR_RATES)
389 * Find and set the topmost probability rate per sta and per group
392 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
394 struct minstrel_mcs_group_data *mg;
395 struct minstrel_rate_stats *mrs;
396 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
397 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
398 int max_gpr_group, max_gpr_idx;
399 int max_gpr_tp_avg, max_gpr_prob;
401 cur_group = index / MCS_GROUP_RATES;
402 cur_idx = index % MCS_GROUP_RATES;
403 mg = &mi->groups[index / MCS_GROUP_RATES];
404 mrs = &mg->rates[index % MCS_GROUP_RATES];
406 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
407 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
408 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
409 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
411 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
412 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
413 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
414 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
415 (max_tp_group != MINSTREL_CCK_GROUP))
418 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
419 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
420 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
422 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
423 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
425 if (cur_tp_avg > tmp_tp_avg)
426 mi->max_prob_rate = index;
428 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
431 if (cur_tp_avg > max_gpr_tp_avg)
432 mg->max_group_prob_rate = index;
434 if (mrs->prob_ewma > tmp_prob)
435 mi->max_prob_rate = index;
436 if (mrs->prob_ewma > max_gpr_prob)
437 mg->max_group_prob_rate = index;
443 * Assign new rate set per sta and use CCK rates only if the fastest
444 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
445 * rate sets where MCS and CCK rates are mixed, because CCK rates can
446 * not use aggregation.
449 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
450 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
451 u16 tmp_cck_tp_rate[MAX_THR_RATES])
453 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
456 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
457 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
458 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
459 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
461 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
462 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
463 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
464 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
466 if (tmp_cck_tp > tmp_mcs_tp) {
467 for(i = 0; i < MAX_THR_RATES; i++) {
468 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
476 * Try to increase robustness of max_prob rate by decrease number of
477 * streams if possible.
480 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
482 struct minstrel_mcs_group_data *mg;
483 int tmp_max_streams, group, tmp_idx, tmp_prob;
486 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
487 MCS_GROUP_RATES].streams;
488 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
489 mg = &mi->groups[group];
490 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
493 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
494 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
496 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
497 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
498 mi->max_prob_rate = mg->max_group_prob_rate;
499 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
507 * Update rate statistics and select new primary rates
509 * Rules for rate selection:
510 * - max_prob_rate must use only one stream, as a tradeoff between delivery
511 * probability and throughput during strong fluctuations
512 * - as long as the max prob rate has a probability of more than 75%, pick
513 * higher throughput rates, even if the probablity is a bit lower
516 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
518 struct minstrel_mcs_group_data *mg;
519 struct minstrel_rate_stats *mrs;
520 int group, i, j, cur_prob;
521 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
522 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
524 if (mi->ampdu_packets > 0) {
525 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
526 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
528 mi->ampdu_packets = 0;
532 mi->sample_count = 0;
534 /* Initialize global rate indexes */
535 for(j = 0; j < MAX_THR_RATES; j++){
536 tmp_mcs_tp_rate[j] = 0;
537 tmp_cck_tp_rate[j] = 0;
540 /* Find best rate sets within all MCS groups*/
541 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
543 mg = &mi->groups[group];
544 if (!mi->supported[group])
549 /* (re)Initialize group rate indexes */
550 for(j = 0; j < MAX_THR_RATES; j++)
551 tmp_group_tp_rate[j] = group;
553 for (i = 0; i < MCS_GROUP_RATES; i++) {
554 if (!(mi->supported[group] & BIT(i)))
557 index = MCS_GROUP_RATES * group + i;
560 mrs->retry_updated = false;
561 minstrel_calc_rate_stats(mrs);
562 cur_prob = mrs->prob_ewma;
564 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
567 /* Find max throughput rate set */
568 if (group != MINSTREL_CCK_GROUP) {
569 minstrel_ht_sort_best_tp_rates(mi, index,
571 } else if (group == MINSTREL_CCK_GROUP) {
572 minstrel_ht_sort_best_tp_rates(mi, index,
576 /* Find max throughput rate set within a group */
577 minstrel_ht_sort_best_tp_rates(mi, index,
580 /* Find max probability rate per group and global */
581 minstrel_ht_set_best_prob_rate(mi, index);
584 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
585 sizeof(mg->max_group_tp_rate));
588 /* Assign new rate set per sta */
589 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
590 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
592 /* Try to increase robustness of max_prob_rate*/
593 minstrel_ht_prob_rate_reduce_streams(mi);
595 /* try to sample all available rates during each interval */
596 mi->sample_count *= 8;
598 #ifdef CONFIG_MAC80211_DEBUGFS
599 /* use fixed index if set */
600 if (mp->fixed_rate_idx != -1) {
601 for (i = 0; i < 4; i++)
602 mi->max_tp_rate[i] = mp->fixed_rate_idx;
603 mi->max_prob_rate = mp->fixed_rate_idx;
607 /* Reset update timer */
608 mi->last_stats_update = jiffies;
612 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
620 if (rate->flags & IEEE80211_TX_RC_MCS ||
621 rate->flags & IEEE80211_TX_RC_VHT_MCS)
624 return rate->idx == mp->cck_rates[0] ||
625 rate->idx == mp->cck_rates[1] ||
626 rate->idx == mp->cck_rates[2] ||
627 rate->idx == mp->cck_rates[3];
631 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
633 struct minstrel_mcs_group_data *mg;
637 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
638 mg = &mi->groups[mi->sample_group];
640 if (!mi->supported[mi->sample_group])
643 if (++mg->index >= MCS_GROUP_RATES) {
645 if (++mg->column >= ARRAY_SIZE(sample_table))
653 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
655 int group, orig_group;
657 orig_group = group = *idx / MCS_GROUP_RATES;
661 if (!mi->supported[group])
664 if (minstrel_mcs_groups[group].streams >
665 minstrel_mcs_groups[orig_group].streams)
669 *idx = mi->groups[group].max_group_tp_rate[0];
671 *idx = mi->groups[group].max_group_tp_rate[1];
677 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
679 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
680 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
683 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
686 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
689 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
692 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
693 if (likely(sta->ampdu_mlme.tid_tx[tid]))
696 ieee80211_start_tx_ba_session(pubsta, tid, 0);
700 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
701 struct ieee80211_sta *sta, void *priv_sta,
702 struct ieee80211_tx_info *info)
704 struct minstrel_ht_sta_priv *msp = priv_sta;
705 struct minstrel_ht_sta *mi = &msp->ht;
706 struct ieee80211_tx_rate *ar = info->status.rates;
707 struct minstrel_rate_stats *rate, *rate2;
708 struct minstrel_priv *mp = priv;
709 bool last, update = false;
713 return mac80211_minstrel.tx_status_noskb(priv, sband, sta,
716 /* This packet was aggregated but doesn't carry status info */
717 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
718 !(info->flags & IEEE80211_TX_STAT_AMPDU))
721 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
722 info->status.ampdu_ack_len =
723 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
724 info->status.ampdu_len = 1;
728 mi->ampdu_len += info->status.ampdu_len;
730 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
731 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
732 mi->sample_tries = 1;
736 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
737 mi->sample_packets += info->status.ampdu_len;
739 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
740 for (i = 0; !last; i++) {
741 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
742 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
744 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
747 rate->success += info->status.ampdu_ack_len;
749 rate->attempts += ar[i].count * info->status.ampdu_len;
753 * check for sudden death of spatial multiplexing,
754 * downgrade to a lower number of streams if necessary.
756 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
757 if (rate->attempts > 30 &&
758 MINSTREL_FRAC(rate->success, rate->attempts) <
759 MINSTREL_FRAC(20, 100)) {
760 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
764 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
765 if (rate2->attempts > 30 &&
766 MINSTREL_FRAC(rate2->success, rate2->attempts) <
767 MINSTREL_FRAC(20, 100)) {
768 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
772 if (time_after(jiffies, mi->last_stats_update +
773 (mp->update_interval / 2 * HZ) / 1000)) {
775 minstrel_ht_update_stats(mp, mi);
779 minstrel_ht_update_rates(mp, mi);
783 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
786 struct minstrel_rate_stats *mrs;
787 const struct mcs_group *group;
788 unsigned int tx_time, tx_time_rtscts, tx_time_data;
789 unsigned int cw = mp->cw_min;
790 unsigned int ctime = 0;
791 unsigned int t_slot = 9; /* FIXME */
792 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
793 unsigned int overhead = 0, overhead_rtscts = 0;
795 mrs = minstrel_get_ratestats(mi, index);
796 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
797 mrs->retry_count = 1;
798 mrs->retry_count_rtscts = 1;
802 mrs->retry_count = 2;
803 mrs->retry_count_rtscts = 2;
804 mrs->retry_updated = true;
806 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
807 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
809 /* Contention time for first 2 tries */
810 ctime = (t_slot * cw) >> 1;
811 cw = min((cw << 1) | 1, mp->cw_max);
812 ctime += (t_slot * cw) >> 1;
813 cw = min((cw << 1) | 1, mp->cw_max);
815 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
816 overhead = mi->overhead;
817 overhead_rtscts = mi->overhead_rtscts;
820 /* Total TX time for data and Contention after first 2 tries */
821 tx_time = ctime + 2 * (overhead + tx_time_data);
822 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
824 /* See how many more tries we can fit inside segment size */
826 /* Contention time for this try */
827 ctime = (t_slot * cw) >> 1;
828 cw = min((cw << 1) | 1, mp->cw_max);
830 /* Total TX time after this try */
831 tx_time += ctime + overhead + tx_time_data;
832 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
834 if (tx_time_rtscts < mp->segment_size)
835 mrs->retry_count_rtscts++;
836 } while ((tx_time < mp->segment_size) &&
837 (++mrs->retry_count < mp->max_retry));
842 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
843 struct ieee80211_sta_rates *ratetbl, int offset, int index)
845 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
846 struct minstrel_rate_stats *mrs;
848 u16 flags = group->flags;
850 mrs = minstrel_get_ratestats(mi, index);
851 if (!mrs->retry_updated)
852 minstrel_calc_retransmit(mp, mi, index);
854 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
855 ratetbl->rate[offset].count = 2;
856 ratetbl->rate[offset].count_rts = 2;
857 ratetbl->rate[offset].count_cts = 2;
859 ratetbl->rate[offset].count = mrs->retry_count;
860 ratetbl->rate[offset].count_cts = mrs->retry_count;
861 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
864 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
865 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
866 else if (flags & IEEE80211_TX_RC_VHT_MCS)
867 idx = ((group->streams - 1) << 4) |
868 ((index % MCS_GROUP_RATES) & 0xF);
870 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
872 /* enable RTS/CTS if needed:
873 * - if station is in dynamic SMPS (and streams > 1)
874 * - for fallback rates, to increase chances of getting through
877 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
878 group->streams > 1)) {
879 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
880 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
883 ratetbl->rate[offset].idx = idx;
884 ratetbl->rate[offset].flags = flags;
888 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
890 int group = rate / MCS_GROUP_RATES;
891 rate %= MCS_GROUP_RATES;
892 return mi->groups[group].rates[rate].prob_ewma;
896 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
898 int group = mi->max_prob_rate / MCS_GROUP_RATES;
899 const struct mcs_group *g = &minstrel_mcs_groups[group];
900 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
902 /* Disable A-MSDU if max_prob_rate is bad */
903 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
906 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
907 if (g->duration[rate] > MCS_DURATION(1, 0, 52))
911 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
914 if (g->duration[rate] > MCS_DURATION(1, 0, 104))
918 * If the rate is slower than single-stream MCS7, or if the max throughput
919 * rate success probability is less than 75%, limit A-MSDU to twice the usual
922 if (g->duration[rate] > MCS_DURATION(1, 0, 260) ||
923 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
924 MINSTREL_FRAC(75, 100)))
928 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
929 * Since aggregation sessions are started/stopped without txq flush, use
930 * the limit here to avoid the complexity of having to de-aggregate
931 * packets in the queue.
933 if (!mi->sta->vht_cap.vht_supported)
934 return IEEE80211_MAX_MPDU_LEN_HT_BA;
941 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
943 struct ieee80211_sta_rates *rates;
946 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
950 /* Start with max_tp_rate[0] */
951 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
953 if (mp->hw->max_rates >= 3) {
954 /* At least 3 tx rates supported, use max_tp_rate[1] next */
955 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
958 if (mp->hw->max_rates >= 2) {
960 * At least 2 tx rates supported, use max_prob_rate next */
961 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
964 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
965 rates->rate[i].idx = -1;
966 rate_control_set_rates(mp->hw, mi->sta, rates);
970 minstrel_get_duration(int index)
972 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
973 return group->duration[index % MCS_GROUP_RATES];
977 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
979 struct minstrel_rate_stats *mrs;
980 struct minstrel_mcs_group_data *mg;
981 unsigned int sample_dur, sample_group, cur_max_tp_streams;
982 int tp_rate1, tp_rate2;
985 if (mi->sample_wait > 0) {
990 if (!mi->sample_tries)
993 sample_group = mi->sample_group;
994 mg = &mi->groups[sample_group];
995 sample_idx = sample_table[mg->column][mg->index];
996 minstrel_set_next_sample_idx(mi);
998 if (!(mi->supported[sample_group] & BIT(sample_idx)))
1001 mrs = &mg->rates[sample_idx];
1002 sample_idx += sample_group * MCS_GROUP_RATES;
1004 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
1005 if (minstrel_get_duration(mi->max_tp_rate[0]) >
1006 minstrel_get_duration(mi->max_tp_rate[1])) {
1007 tp_rate1 = mi->max_tp_rate[1];
1008 tp_rate2 = mi->max_tp_rate[0];
1010 tp_rate1 = mi->max_tp_rate[0];
1011 tp_rate2 = mi->max_tp_rate[1];
1015 * Sampling might add some overhead (RTS, no aggregation)
1016 * to the frame. Hence, don't use sampling for the highest currently
1017 * used highest throughput or probability rate.
1019 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1023 * Do not sample if the probability is already higher than 95%
1024 * to avoid wasting airtime.
1026 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100))
1030 * Make sure that lower rates get sampled only occasionally,
1031 * if the link is working perfectly.
1034 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1035 MCS_GROUP_RATES].streams;
1036 sample_dur = minstrel_get_duration(sample_idx);
1037 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1038 (cur_max_tp_streams - 1 <
1039 minstrel_mcs_groups[sample_group].streams ||
1040 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1041 if (mrs->sample_skipped < 20)
1044 if (mi->sample_slow++ > 2)
1053 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1054 struct ieee80211_tx_rate_control *txrc)
1056 const struct mcs_group *sample_group;
1057 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1058 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1059 struct minstrel_ht_sta_priv *msp = priv_sta;
1060 struct minstrel_ht_sta *mi = &msp->ht;
1061 struct minstrel_priv *mp = priv;
1064 if (rate_control_send_low(sta, priv_sta, txrc))
1068 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1070 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1071 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1072 minstrel_aggr_check(sta, txrc->skb);
1074 info->flags |= mi->tx_flags;
1076 #ifdef CONFIG_MAC80211_DEBUGFS
1077 if (mp->fixed_rate_idx != -1)
1081 /* Don't use EAPOL frames for sampling on non-mrr hw */
1082 if (mp->hw->max_rates == 1 &&
1083 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1086 sample_idx = minstrel_get_sample_rate(mp, mi);
1088 mi->total_packets++;
1091 if (mi->total_packets == ~0) {
1092 mi->total_packets = 0;
1093 mi->sample_packets = 0;
1099 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1100 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1103 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1104 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1105 rate->idx = mp->cck_rates[idx];
1106 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1107 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1108 sample_group->streams);
1110 rate->idx = sample_idx % MCS_GROUP_RATES +
1111 (sample_group->streams - 1) * 8;
1114 rate->flags = sample_group->flags;
1118 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1119 struct ieee80211_supported_band *sband,
1120 struct ieee80211_sta *sta)
1124 if (sband->band != NL80211_BAND_2GHZ)
1127 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1130 mi->cck_supported = 0;
1131 mi->cck_supported_short = 0;
1132 for (i = 0; i < 4; i++) {
1133 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1136 mi->cck_supported |= BIT(i);
1137 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1138 mi->cck_supported_short |= BIT(i);
1141 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1145 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1146 struct cfg80211_chan_def *chandef,
1147 struct ieee80211_sta *sta, void *priv_sta)
1149 struct minstrel_priv *mp = priv;
1150 struct minstrel_ht_sta_priv *msp = priv_sta;
1151 struct minstrel_ht_sta *mi = &msp->ht;
1152 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1153 u16 sta_cap = sta->ht_cap.cap;
1154 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1155 struct sta_info *sinfo = container_of(sta, struct sta_info, sta);
1157 int n_supported = 0;
1162 /* fall back to the old minstrel for legacy stations */
1163 if (!sta->ht_cap.ht_supported)
1166 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1168 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1169 if (vht_cap->vht_supported)
1170 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1176 memset(mi, 0, sizeof(*mi));
1179 mi->last_stats_update = jiffies;
1181 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1182 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1183 mi->overhead += ack_dur;
1184 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1186 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1188 /* When using MRR, sample more on the first attempt, without delay */
1190 mi->sample_count = 16;
1191 mi->sample_wait = 0;
1193 mi->sample_count = 8;
1194 mi->sample_wait = 8;
1196 mi->sample_tries = 4;
1198 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1200 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1201 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1202 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1204 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1205 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1208 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1209 u32 gflags = minstrel_mcs_groups[i].flags;
1212 mi->supported[i] = 0;
1213 if (i == MINSTREL_CCK_GROUP) {
1214 minstrel_ht_update_cck(mp, mi, sband, sta);
1218 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1219 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1220 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1223 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1228 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1229 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1232 nss = minstrel_mcs_groups[i].streams;
1234 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1235 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1239 if (gflags & IEEE80211_TX_RC_MCS) {
1240 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1241 if (use_vht && minstrel_vht_only)
1244 mi->supported[i] = mcs->rx_mask[nss - 1];
1245 if (mi->supported[i])
1251 if (!vht_cap->vht_supported ||
1252 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1253 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1256 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1257 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1258 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1259 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1264 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1266 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1271 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1272 vht_cap->vht_mcs.tx_mcs_map);
1274 if (mi->supported[i])
1281 if (test_sta_flag(sinfo, WLAN_STA_SHORT_PREAMBLE))
1282 mi->cck_supported_short |= mi->cck_supported_short << 4;
1284 /* create an initial rate table with the lowest supported rates */
1285 minstrel_ht_update_stats(mp, mi);
1286 minstrel_ht_update_rates(mp, mi);
1292 memset(&msp->legacy, 0, sizeof(msp->legacy));
1293 msp->legacy.r = msp->ratelist;
1294 msp->legacy.sample_table = msp->sample_table;
1295 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1300 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1301 struct cfg80211_chan_def *chandef,
1302 struct ieee80211_sta *sta, void *priv_sta)
1304 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1308 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1309 struct cfg80211_chan_def *chandef,
1310 struct ieee80211_sta *sta, void *priv_sta,
1313 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1317 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1319 struct ieee80211_supported_band *sband;
1320 struct minstrel_ht_sta_priv *msp;
1321 struct minstrel_priv *mp = priv;
1322 struct ieee80211_hw *hw = mp->hw;
1326 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1327 sband = hw->wiphy->bands[i];
1328 if (sband && sband->n_bitrates > max_rates)
1329 max_rates = sband->n_bitrates;
1332 msp = kzalloc(sizeof(*msp), gfp);
1336 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1340 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1341 if (!msp->sample_table)
1347 kfree(msp->ratelist);
1354 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1356 struct minstrel_ht_sta_priv *msp = priv_sta;
1358 kfree(msp->sample_table);
1359 kfree(msp->ratelist);
1364 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1366 return mac80211_minstrel.alloc(hw, debugfsdir);
1370 minstrel_ht_free(void *priv)
1372 mac80211_minstrel.free(priv);
1375 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1377 struct minstrel_ht_sta_priv *msp = priv_sta;
1378 struct minstrel_ht_sta *mi = &msp->ht;
1379 int i, j, prob, tp_avg;
1382 return mac80211_minstrel.get_expected_throughput(priv_sta);
1384 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1385 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1386 prob = mi->groups[i].rates[j].prob_ewma;
1388 /* convert tp_avg from pkt per second in kbps */
1389 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1390 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1395 static const struct rate_control_ops mac80211_minstrel_ht = {
1396 .name = "minstrel_ht",
1397 .tx_status_noskb = minstrel_ht_tx_status,
1398 .get_rate = minstrel_ht_get_rate,
1399 .rate_init = minstrel_ht_rate_init,
1400 .rate_update = minstrel_ht_rate_update,
1401 .alloc_sta = minstrel_ht_alloc_sta,
1402 .free_sta = minstrel_ht_free_sta,
1403 .alloc = minstrel_ht_alloc,
1404 .free = minstrel_ht_free,
1405 #ifdef CONFIG_MAC80211_DEBUGFS
1406 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1407 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1409 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1413 static void __init init_sample_table(void)
1415 int col, i, new_idx;
1416 u8 rnd[MCS_GROUP_RATES];
1418 memset(sample_table, 0xff, sizeof(sample_table));
1419 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1420 prandom_bytes(rnd, sizeof(rnd));
1421 for (i = 0; i < MCS_GROUP_RATES; i++) {
1422 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1423 while (sample_table[col][new_idx] != 0xff)
1424 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1426 sample_table[col][new_idx] = i;
1432 rc80211_minstrel_ht_init(void)
1434 init_sample_table();
1435 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1439 rc80211_minstrel_ht_exit(void)
1441 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);