package/mac80211/patches/560-minstrel_ht.patch

   1 --- a/net/mac80211/Makefile
   2 +++ b/net/mac80211/Makefile
   3 @@ -47,8 +47,8 @@ CFLAGS_driver-trace.o := -I$(src)
   4  rc80211_pid-y := rc80211_pid_algo.o
   5  rc80211_pid-$(CONFIG_MAC80211_DEBUGFS) += rc80211_pid_debugfs.o
   6
   7 -rc80211_minstrel-y := rc80211_minstrel.o
   8 -rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o
   9 +rc80211_minstrel-y := rc80211_minstrel.o rc80211_minstrel_ht.o
  10 +rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o rc80211_minstrel_ht_debugfs.o
  11
  12  mac80211-$(CONFIG_MAC80211_RC_PID) += $(rc80211_pid-y)
  13  mac80211-$(CONFIG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)
  14 --- a/net/mac80211/main.c
  15 +++ b/net/mac80211/main.c
  16 @@ -714,6 +714,10 @@ static int __init ieee80211_init(void)
  17         if (ret)
  18                 return ret;
  19
  20 +       ret = rc80211_minstrel_ht_init();
  21 +       if (ret)
  22 +               goto err_minstrel;
  23 +
  24         ret = rc80211_pid_init();
  25         if (ret)
  26                 goto err_pid;
  27 @@ -726,6 +730,8 @@ static int __init ieee80211_init(void)
  28   err_netdev:
  29         rc80211_pid_exit();
  30   err_pid:
  31 +       rc80211_minstrel_ht_exit();
  32 + err_minstrel:
  33         rc80211_minstrel_exit();
  34
  35         return ret;
  36 @@ -734,6 +740,7 @@ static int __init ieee80211_init(void)
  37  static void __exit ieee80211_exit(void)
  38  {
  39         rc80211_pid_exit();
  40 +       rc80211_minstrel_ht_exit();
  41         rc80211_minstrel_exit();
  42
  43         /*
  44 --- a/net/mac80211/rate.h
  45 +++ b/net/mac80211/rate.h
  46 @@ -137,6 +137,8 @@ static inline void rc80211_pid_exit(void
  47  #ifdef CONFIG_MAC80211_RC_MINSTREL
  48  extern int rc80211_minstrel_init(void);
  49  extern void rc80211_minstrel_exit(void);
  50 +extern int rc80211_minstrel_ht_init(void);
  51 +extern void rc80211_minstrel_ht_exit(void);
  52  #else
  53  static inline int rc80211_minstrel_init(void)
  54  {
  55 @@ -145,6 +147,13 @@ static inline int rc80211_minstrel_init(
  56  static inline void rc80211_minstrel_exit(void)
  57  {
  58  }
  59 +static inline int rc80211_minstrel_ht_init(void)
  60 +{
  61 +       return 0;
  62 +}
  63 +static inline void rc80211_minstrel_ht_exit(void)
  64 +{
  65 +}
  66  #endif
  67
  68
  69 --- /dev/null
  70 +++ b/net/mac80211/rc80211_minstrel_ht.c
  71 @@ -0,0 +1,809 @@
  72 +/*
  73 + * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
  74 + *
  75 + * This program is free software; you can redistribute it and/or modify
  76 + * it under the terms of the GNU General Public License version 2 as
  77 + * published by the Free Software Foundation.
  78 + */
  79 +#include <linux/netdevice.h>
  80 +#include <linux/types.h>
  81 +#include <linux/skbuff.h>
  82 +#include <linux/debugfs.h>
  83 +#include <linux/random.h>
  84 +#include <linux/ieee80211.h>
  85 +#include <net/mac80211.h>
  86 +#include "rate.h"
  87 +#include "rc80211_minstrel.h"
  88 +#include "rc80211_minstrel_ht.h"
  89 +
  90 +#define AVG_PKT_SIZE   1200
  91 +#define SAMPLE_COLUMNS 10
  92 +#define EWMA_LEVEL             75
  93 +
  94 +/* Number of bits for an average sized packet */
  95 +#define MCS_NBITS (AVG_PKT_SIZE << 3)
  96 +
  97 +/* Number of symbols for a packet with (bps) bits per symbol */
  98 +#define MCS_NSYMS(bps) ((MCS_NBITS + (bps) - 1) / (bps))
  99 +
 100 +/* Transmission time for a packet containing (syms) symbols */
 101 +#define MCS_SYMBOL_TIME(sgi, syms)                                     \
 102 +       (sgi ?                                                          \
 103 +         ((syms) * 18 + 4) / 5 :       /* syms * 3.6 us */             \
 104 +         (syms) << 2                   /* syms * 4 us */               \
 105 +       )
 106 +
 107 +/* Transmit duration for the raw data part of an average sized packet */
 108 +#define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
 109 +
 110 +/* MCS rate information for an MCS group */
 111 +#define MCS_GROUP(_streams, _sgi, _ht40) {                             \
 112 +       .streams = _streams,                                            \
 113 +       .flags =                                                        \
 114 +               (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |                 \
 115 +               (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),             \
 116 +       .duration = {                                                   \
 117 +               MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26),          \
 118 +               MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52),         \
 119 +               MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78),         \
 120 +               MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104),        \
 121 +               MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156),        \
 122 +               MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208),        \
 123 +               MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234),        \
 124 +               MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260)         \
 125 +       }                                                               \
 126 +}
 127 +
 128 +/*
 129 + * To enable sufficiently targeted rate sampling, MCS rates are divided into
 130 + * groups, based on the number of streams and flags (HT40, SGI) that they
 131 + * use.
 132 + */
 133 +const struct mcs_group minstrel_mcs_groups[] = {
 134 +       MCS_GROUP(1, 0, 0),
 135 +       MCS_GROUP(2, 0, 0),
 136 +#if MINSTREL_MAX_STREAMS >= 3
 137 +       MCS_GROUP(3, 0, 0),
 138 +#endif
 139 +
 140 +       MCS_GROUP(1, 1, 0),
 141 +       MCS_GROUP(2, 1, 0),
 142 +#if MINSTREL_MAX_STREAMS >= 3
 143 +       MCS_GROUP(3, 1, 0),
 144 +#endif
 145 +
 146 +       MCS_GROUP(1, 0, 1),
 147 +       MCS_GROUP(2, 0, 1),
 148 +#if MINSTREL_MAX_STREAMS >= 3
 149 +       MCS_GROUP(3, 0, 1),
 150 +#endif
 151 +
 152 +       MCS_GROUP(1, 1, 1),
 153 +       MCS_GROUP(2, 1, 1),
 154 +#if MINSTREL_MAX_STREAMS >= 3
 155 +       MCS_GROUP(3, 1, 1),
 156 +#endif
 157 +};
 158 +
 159 +static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];
 160 +
 161 +/*
 162 + * Perform EWMA (Exponentially Weighted Moving Average) calculation
 163 + */
 164 +static int
 165 +minstrel_ewma(int old, int new, int weight)
 166 +{
 167 +       return (new * (100 - weight) + old * weight) / 100;
 168 +}
 169 +
 170 +/*
 171 + * Look up an MCS group index based on mac80211 rate information
 172 + */
 173 +static int
 174 +minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
 175 +{
 176 +       int streams = (rate->idx / MCS_GROUP_RATES) + 1;
 177 +       u32 flags = IEEE80211_TX_RC_SHORT_GI | IEEE80211_TX_RC_40_MHZ_WIDTH;
 178 +       int i;
 179 +
 180 +       for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
 181 +               if (minstrel_mcs_groups[i].streams != streams)
 182 +                       continue;
 183 +               if (minstrel_mcs_groups[i].flags != (rate->flags & flags))
 184 +                       continue;
 185 +
 186 +               return i;
 187 +       }
 188 +
 189 +       WARN_ON(1);
 190 +       return 0;
 191 +}
 192 +
 193 +static inline struct minstrel_rate_stats *
 194 +minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
 195 +{
 196 +       return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
 197 +}
 198 +
 199 +
 200 +/*
 201 + * Recalculate success probabilities and counters for a rate using EWMA
 202 + */
 203 +static void
 204 +minstrel_calc_rate_ewma(struct minstrel_priv *mp, struct minstrel_rate_stats *mr)
 205 +{
 206 +       if (unlikely(mr->attempts > 0)) {
 207 +               mr->sample_skipped = 0;
 208 +               mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
 209 +               if (!mr->att_hist)
 210 +                       mr->probability = mr->cur_prob;
 211 +               else
 212 +                       mr->probability = minstrel_ewma(mr->probability,
 213 +                               mr->cur_prob, EWMA_LEVEL);
 214 +               mr->att_hist += mr->attempts;
 215 +               mr->succ_hist += mr->success;
 216 +       } else {
 217 +               mr->sample_skipped++;
 218 +       }
 219 +       mr->last_success = mr->success;
 220 +       mr->last_attempts = mr->attempts;
 221 +       mr->success = 0;
 222 +       mr->attempts = 0;
 223 +}
 224 +
 225 +/*
 226 + * Calculate throughput based on the average A-MPDU length, taking into account
 227 + * the expected number of retransmissions and their expected length
 228 + */
 229 +static void
 230 +minstrel_ht_calc_tp(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 231 +                    int group, int rate)
 232 +{
 233 +       struct minstrel_rate_stats *mr;
 234 +       unsigned int usecs;
 235 +
 236 +       mr = &mi->groups[group].rates[rate];
 237 +
 238 +       if (mr->probability < MINSTREL_FRAC(1, 10)) {
 239 +               mr->cur_tp = 0;
 240 +               return;
 241 +       }
 242 +
 243 +       usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
 244 +       usecs += minstrel_mcs_groups[group].duration[rate];
 245 +       mr->cur_tp = MINSTREL_TRUNC((1000000 / usecs) * mr->probability);
 246 +}
 247 +
 248 +/*
 249 + * Update rate statistics and select new primary rates
 250 + *
 251 + * Rules for rate selection:
 252 + *  - max_prob_rate must use only one stream, as a tradeoff between delivery
 253 + *    probability and throughput during strong fluctuations
 254 + *  - as long as the max prob rate has a probability of more than 3/4, pick
 255 + *    higher throughput rates, even if the probablity is a bit lower
 256 + */
 257 +static void
 258 +minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 259 +{
 260 +       struct minstrel_mcs_group_data *mg;
 261 +       struct minstrel_rate_stats *mr;
 262 +       int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
 263 +       int group, i, index;
 264 +
 265 +       mi->sample_slow = 0;
 266 +       mi->sample_count = 0;
 267 +       mi->max_tp_rate = 0;
 268 +       mi->max_tp_rate2 = 0;
 269 +       mi->max_prob_rate = 0;
 270 +
 271 +       for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 272 +               cur_prob = 0;
 273 +               cur_prob_tp = 0;
 274 +               cur_tp = 0;
 275 +               cur_tp2 = 0;
 276 +
 277 +               mg = &mi->groups[group];
 278 +               if (!mg->supported)
 279 +                       continue;
 280 +
 281 +               mg->max_tp_rate = 0;
 282 +               mg->max_tp_rate2 = 0;
 283 +               mg->max_prob_rate = 0;
 284 +               mi->sample_count++;
 285 +
 286 +               for (i = 0; i < MCS_GROUP_RATES; i++) {
 287 +                       if (!(mg->supported & BIT(i)))
 288 +                               continue;
 289 +
 290 +                       mr = &mg->rates[i];
 291 +                       mr->retry_updated = false;
 292 +                       index = MCS_GROUP_RATES * group + i;
 293 +                       minstrel_calc_rate_ewma(mp, mr);
 294 +                       minstrel_ht_calc_tp(mp, mi, group, i);
 295 +
 296 +                       if (!mr->cur_tp)
 297 +                               continue;
 298 +
 299 +                       /* ignore the lowest rate of each single-stream group */
 300 +                       if (!i && minstrel_mcs_groups[group].streams == 1)
 301 +                               continue;
 302 +
 303 +                       if ((mr->cur_tp > cur_prob_tp && mr->probability >
 304 +                            MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
 305 +                               mg->max_prob_rate = index;
 306 +                               cur_prob = mr->probability;
 307 +                       }
 308 +
 309 +                       if (mr->cur_tp > cur_tp) {
 310 +                               swap(index, mg->max_tp_rate);
 311 +                               cur_tp = mr->cur_tp;
 312 +                               mr = minstrel_get_ratestats(mi, index);
 313 +                       }
 314 +
 315 +                       if (index >= mg->max_tp_rate)
 316 +                               continue;
 317 +
 318 +                       if (mr->cur_tp > cur_tp2) {
 319 +                               mg->max_tp_rate2 = index;
 320 +                               cur_tp2 = mr->cur_tp;
 321 +                       }
 322 +               }
 323 +       }
 324 +
 325 +       /* try to sample up to half of the availble rates during each interval */
 326 +       mi->sample_count *= 4;
 327 +
 328 +       cur_prob = 0;
 329 +       cur_prob_tp = 0;
 330 +       cur_tp = 0;
 331 +       cur_tp2 = 0;
 332 +       for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 333 +               mg = &mi->groups[group];
 334 +               if (!mg->supported)
 335 +                       continue;
 336 +
 337 +               mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
 338 +               if (cur_prob_tp < mr->cur_tp &&
 339 +                   minstrel_mcs_groups[group].streams == 1) {
 340 +                       mi->max_prob_rate = mg->max_prob_rate;
 341 +                       cur_prob = mr->cur_prob;
 342 +               }
 343 +
 344 +               mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
 345 +               if (cur_tp < mr->cur_tp) {
 346 +                       mi->max_tp_rate = mg->max_tp_rate;
 347 +                       cur_tp = mr->cur_tp;
 348 +               }
 349 +
 350 +               mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
 351 +               if (cur_tp2 < mr->cur_tp) {
 352 +                       mi->max_tp_rate2 = mg->max_tp_rate2;
 353 +                       cur_tp2 = mr->cur_tp;
 354 +               }
 355 +       }
 356 +
 357 +       mi->stats_update = jiffies;
 358 +}
 359 +
 360 +static bool
 361 +minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
 362 +{
 363 +       if (!rate->count)
 364 +               return false;
 365 +
 366 +       if (rate->idx < 0)
 367 +               return false;
 368 +
 369 +       return !!(rate->flags & IEEE80211_TX_RC_MCS);
 370 +}
 371 +
 372 +static void
 373 +minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
 374 +{
 375 +       struct minstrel_mcs_group_data *mg;
 376 +
 377 +       for (;;) {
 378 +               mi->sample_group++;
 379 +               mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
 380 +               mg = &mi->groups[mi->sample_group];
 381 +
 382 +               if (!mg->supported)
 383 +                       continue;
 384 +
 385 +               if (++mg->index > MCS_GROUP_RATES) {
 386 +                       mg->index = 0;
 387 +                       if (++mg->column > ARRAY_SIZE(sample_table))
 388 +                               mg->column = 0;
 389 +               }
 390 +               break;
 391 +       }
 392 +}
 393 +
 394 +static void
 395 +minstrel_downgrade_rate(struct minstrel_ht_sta *mi, int *idx, bool primary)
 396 +{
 397 +       int group, orig_group;
 398 +
 399 +       orig_group = group = *idx / MCS_GROUP_RATES;
 400 +       while (group > 0) {
 401 +               group--;
 402 +
 403 +               if (!mi->groups[group].supported)
 404 +                       continue;
 405 +
 406 +               if (minstrel_mcs_groups[group].streams >
 407 +                   minstrel_mcs_groups[orig_group].streams)
 408 +                       continue;
 409 +
 410 +               if (primary)
 411 +                       *idx = mi->groups[group].max_tp_rate;
 412 +               else
 413 +                       *idx = mi->groups[group].max_tp_rate2;
 414 +               break;
 415 +       }
 416 +}
 417 +
 418 +
 419 +static void
 420 +minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
 421 +                      struct ieee80211_sta *sta, void *priv_sta,
 422 +                      struct sk_buff *skb)
 423 +{
 424 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 425 +       struct minstrel_ht_sta *mi = &msp->ht;
 426 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 427 +       struct ieee80211_tx_rate *ar = info->status.rates;
 428 +       struct minstrel_rate_stats *rate, *rate2;
 429 +       struct minstrel_priv *mp = priv;
 430 +       bool last = false;
 431 +       int group;
 432 +       int i = 0;
 433 +
 434 +       if (!msp->is_ht)
 435 +               return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
 436 +
 437 +       /* This packet was aggregated but doesn't carry status info */
 438 +       if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
 439 +           !(info->flags & IEEE80211_TX_STAT_AMPDU))
 440 +               return;
 441 +
 442 +       if (!info->status.ampdu_len) {
 443 +               info->status.ampdu_ack_len = 1;
 444 +               info->status.ampdu_len = 1;
 445 +       }
 446 +
 447 +       mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
 448 +               MINSTREL_FRAC(info->status.ampdu_len, 1), 90);
 449 +
 450 +       if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
 451 +               mi->sample_wait = 4 + MINSTREL_TRUNC(mi->avg_ampdu_len);
 452 +               mi->sample_tries = 3;
 453 +               mi->sample_count--;
 454 +       }
 455 +
 456 +       if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) {
 457 +               mi->sample_packets += info->status.ampdu_len;
 458 +               minstrel_next_sample_idx(mi);
 459 +       }
 460 +
 461 +       for (i = 0; !last; i++) {
 462 +               last = (i == IEEE80211_TX_MAX_RATES - 1) ||
 463 +                      !minstrel_ht_txstat_valid(&ar[i + 1]);
 464 +
 465 +               if (!minstrel_ht_txstat_valid(&ar[i]))
 466 +                       break;
 467 +
 468 +               group = minstrel_ht_get_group_idx(&ar[i]);
 469 +               rate = &mi->groups[group].rates[ar[i].idx % 8];
 470 +
 471 +               if (last && (info->flags & IEEE80211_TX_STAT_ACK))
 472 +                       rate->success += info->status.ampdu_ack_len;
 473 +
 474 +               rate->attempts += ar[i].count * info->status.ampdu_len;
 475 +       }
 476 +
 477 +       /*
 478 +        * check for sudden death of spatial multiplexing,
 479 +        * downgrade to a lower number of streams if necessary.
 480 +        */
 481 +       rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
 482 +       if (rate->attempts > 30 &&
 483 +           MINSTREL_FRAC(rate->success, rate->attempts) <
 484 +           MINSTREL_FRAC(20, 100))
 485 +               minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
 486 +
 487 +       rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
 488 +       if (rate->attempts > 30 &&
 489 +           MINSTREL_FRAC(rate->success, rate->attempts) <
 490 +           MINSTREL_FRAC(20, 100))
 491 +               minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
 492 +
 493 +       if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000))
 494 +               minstrel_ht_update_stats(mp, mi);
 495 +}
 496 +
 497 +static void
 498 +minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 499 +                         int index)
 500 +{
 501 +       struct minstrel_rate_stats *mr;
 502 +       const struct mcs_group *group;
 503 +       unsigned int tx_time, tx_time_rtscts, tx_time_data;
 504 +       unsigned int cw = mp->cw_min;
 505 +       unsigned int t_slot = 9; /* FIXME */
 506 +       unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
 507 +
 508 +       mr = minstrel_get_ratestats(mi, index);
 509 +       if (mr->probability < MINSTREL_FRAC(1, 10)) {
 510 +               mr->retry_count = 1;
 511 +               mr->retry_count_rtscts = 1;
 512 +               return;
 513 +       }
 514 +
 515 +       mr->retry_count = 2;
 516 +       mr->retry_count_rtscts = 2;
 517 +       mr->retry_updated = true;
 518 +
 519 +       group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
 520 +       tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
 521 +       tx_time = 2 * (t_slot + mi->overhead + tx_time_data);
 522 +       tx_time_rtscts = 2 * (t_slot + mi->overhead_rtscts + tx_time_data);
 523 +       do {
 524 +               cw = (cw << 1) | 1;
 525 +               cw = min(cw, mp->cw_max);
 526 +               tx_time += cw + t_slot + mi->overhead;
 527 +               tx_time_rtscts += cw + t_slot + mi->overhead_rtscts;
 528 +               if (tx_time_rtscts < mp->segment_size)
 529 +                       mr->retry_count_rtscts++;
 530 +       } while ((tx_time < mp->segment_size) &&
 531 +                (++mr->retry_count < mp->max_retry));
 532 +}
 533 +
 534 +
 535 +static void
 536 +minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 537 +                     struct ieee80211_tx_rate *rate, int index,
 538 +                     struct ieee80211_tx_rate_control *txrc,
 539 +                     bool sample, bool rtscts)
 540 +{
 541 +       const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
 542 +       struct minstrel_rate_stats *mr;
 543 +
 544 +       mr = minstrel_get_ratestats(mi, index);
 545 +       if (!mr->retry_updated)
 546 +               minstrel_calc_retransmit(mp, mi, index);
 547 +
 548 +       if (mr->probability < MINSTREL_FRAC(20, 100))
 549 +               rate->count = 2;
 550 +       else if (rtscts)
 551 +               rate->count = mr->retry_count_rtscts;
 552 +       else
 553 +               rate->count = mr->retry_count;
 554 +
 555 +       rate->flags = IEEE80211_TX_RC_MCS | group->flags;
 556 +       if (txrc->short_preamble)
 557 +               rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 558 +       if (txrc->rts || rtscts)
 559 +               rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 560 +       rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
 561 +}
 562 +
 563 +static inline int
 564 +minstrel_get_duration(int index)
 565 +{
 566 +       const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
 567 +       return group->duration[index % MCS_GROUP_RATES];
 568 +}
 569 +
 570 +static int
 571 +minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 572 +{
 573 +       struct minstrel_rate_stats *mr;
 574 +       struct minstrel_mcs_group_data *mg;
 575 +       int sample_idx = 0;
 576 +
 577 +       if (mi->sample_wait > 0) {
 578 +               mi->sample_wait--;
 579 +               return -1;
 580 +       }
 581 +
 582 +       if (!mi->sample_tries)
 583 +               return -1;
 584 +
 585 +       mi->sample_tries--;
 586 +       mg = &mi->groups[mi->sample_group];
 587 +       sample_idx = sample_table[mg->column][mg->index];
 588 +       mr = &mg->rates[sample_idx];
 589 +       sample_idx += mi->sample_group * MCS_GROUP_RATES;
 590 +
 591 +       /*
 592 +        * When not using MRR, do not sample if the probability is already
 593 +        * higher than 95% to avoid wasting airtime
 594 +        */
 595 +       if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
 596 +               goto next;
 597 +
 598 +       /*
 599 +        * Make sure that lower rates get sampled only occasionally,
 600 +        * if the link is working perfectly.
 601 +        */
 602 +       if (minstrel_get_duration(sample_idx) >
 603 +           minstrel_get_duration(mi->max_tp_rate)) {
 604 +               if (mr->sample_skipped < 10)
 605 +                       goto next;
 606 +
 607 +               if (mi->sample_slow++ > 2)
 608 +                       goto next;
 609 +       }
 610 +
 611 +       return sample_idx;
 612 +
 613 +next:
 614 +       minstrel_next_sample_idx(mi);
 615 +       return -1;
 616 +}
 617 +
 618 +static void
 619 +minstrel_aggr_check(struct minstrel_priv *mp, struct ieee80211_sta *pubsta, struct sk_buff *skb)
 620 +{
 621 +       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 622 +       struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 623 +       u16 tid;
 624 +
 625 +       if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
 626 +               return;
 627 +
 628 +       if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
 629 +               return;
 630 +
 631 +       tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 632 +       if (likely(sta->ampdu_mlme.tid_state_tx[tid] != HT_AGG_STATE_IDLE))
 633 +               return;
 634 +
 635 +       ieee80211_start_tx_ba_session(pubsta, tid);
 636 +}
 637 +
 638 +static void
 639 +minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
 640 +                     struct ieee80211_tx_rate_control *txrc)
 641 +{
 642 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 643 +       struct ieee80211_tx_rate *ar = info->status.rates;
 644 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 645 +       struct minstrel_ht_sta *mi = &msp->ht;
 646 +       struct minstrel_priv *mp = priv;
 647 +       int sample_idx;
 648 +
 649 +       if (rate_control_send_low(sta, priv_sta, txrc))
 650 +               return;
 651 +
 652 +       if (!msp->is_ht)
 653 +               return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
 654 +
 655 +       minstrel_aggr_check(mp, sta, txrc->skb);
 656 +
 657 +       sample_idx = minstrel_get_sample_rate(mp, mi);
 658 +       if (sample_idx >= 0) {
 659 +               minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
 660 +                       txrc, true, false);
 661 +               minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
 662 +                       txrc, false, true);
 663 +               info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
 664 +       } else {
 665 +               minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
 666 +                       txrc, false, false);
 667 +               minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
 668 +                       txrc, false, true);
 669 +       }
 670 +       minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate, txrc, false, true);
 671 +
 672 +       ar[3].count = 0;
 673 +       ar[3].idx = -1;
 674 +
 675 +       mi->total_packets++;
 676 +
 677 +       /* wraparound */
 678 +       if (mi->total_packets == ~0) {
 679 +               mi->total_packets = 0;
 680 +               mi->sample_packets = 0;
 681 +       }
 682 +}
 683 +
 684 +static void
 685 +minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
 686 +                        struct ieee80211_sta *sta, void *priv_sta,
 687 +                       enum nl80211_channel_type oper_chan_type)
 688 +{
 689 +       struct minstrel_priv *mp = priv;
 690 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 691 +       struct minstrel_ht_sta *mi = &msp->ht;
 692 +       struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
 693 +       struct ieee80211_local *local = hw_to_local(mp->hw);
 694 +       u16 sta_cap = sta->ht_cap.cap;
 695 +       int ack_dur;
 696 +       int i;
 697 +
 698 +       /* fall back to the old minstrel for legacy stations */
 699 +       if (sta && !sta->ht_cap.ht_supported) {
 700 +               msp->is_ht = false;
 701 +               memset(&msp->legacy, 0, sizeof(msp->legacy));
 702 +               msp->legacy.r = msp->ratelist;
 703 +               msp->legacy.sample_table = msp->sample_table;
 704 +               return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
 705 +       }
 706 +
 707 +       BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
 708 +               MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
 709 +
 710 +       msp->is_ht = true;
 711 +       memset(mi, 0, sizeof(*mi));
 712 +       mi->stats_update = jiffies;
 713 +
 714 +       ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1);
 715 +       mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur;
 716 +       mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
 717 +
 718 +       mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
 719 +
 720 +       /* When using MRR, sample more on the first attempt, without delay */
 721 +       if (mp->has_mrr) {
 722 +               mi->sample_count = 16;
 723 +               mi->sample_wait = 0;
 724 +       } else {
 725 +               mi->sample_count = 8;
 726 +               mi->sample_wait = 8;
 727 +       }
 728 +       mi->sample_tries = 4;
 729 +
 730 +       if (oper_chan_type != NL80211_CHAN_HT40MINUS &&
 731 +           oper_chan_type != NL80211_CHAN_HT40PLUS)
 732 +               sta_cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 733 +
 734 +       for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
 735 +               u16 req = 0;
 736 +
 737 +               mi->groups[i].supported = 0;
 738 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
 739 +                       if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 740 +                               req |= IEEE80211_HT_CAP_SGI_40;
 741 +                       else
 742 +                               req |= IEEE80211_HT_CAP_SGI_20;
 743 +               }
 744 +
 745 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 746 +                       req |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 747 +
 748 +               if ((sta_cap & req) != req)
 749 +                       continue;
 750 +
 751 +               mi->groups[i].supported =
 752 +                       mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
 753 +       }
 754 +}
 755 +
 756 +static void
 757 +minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
 758 +                      struct ieee80211_sta *sta, void *priv_sta)
 759 +{
 760 +       struct minstrel_priv *mp = priv;
 761 +
 762 +       minstrel_ht_update_caps(priv, sband, sta, priv_sta, mp->hw->conf.channel_type);
 763 +}
 764 +
 765 +static void
 766 +minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
 767 +                        struct ieee80211_sta *sta, void *priv_sta,
 768 +                        u32 changed, enum nl80211_channel_type oper_chan_type)
 769 +{
 770 +       minstrel_ht_update_caps(priv, sband, sta, priv_sta, oper_chan_type);
 771 +}
 772 +
 773 +static void *
 774 +minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 775 +{
 776 +       struct ieee80211_supported_band *sband;
 777 +       struct minstrel_ht_sta_priv *msp;
 778 +       struct minstrel_priv *mp = priv;
 779 +       struct ieee80211_hw *hw = mp->hw;
 780 +       int max_rates = 0;
 781 +       int i;
 782 +
 783 +       for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
 784 +               sband = hw->wiphy->bands[i];
 785 +               if (sband && sband->n_bitrates > max_rates)
 786 +                       max_rates = sband->n_bitrates;
 787 +       }
 788 +
 789 +       msp = kzalloc(sizeof(struct minstrel_ht_sta), gfp);
 790 +       if (!msp)
 791 +               return NULL;
 792 +
 793 +       msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
 794 +       if (!msp->ratelist)
 795 +               goto error;
 796 +
 797 +       msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
 798 +       if (!msp->sample_table)
 799 +               goto error1;
 800 +
 801 +       return msp;
 802 +
 803 +error1:
 804 +       kfree(msp->sample_table);
 805 +error:
 806 +       kfree(msp);
 807 +       return NULL;
 808 +}
 809 +
 810 +static void
 811 +minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
 812 +{
 813 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 814 +
 815 +       kfree(msp->sample_table);
 816 +       kfree(msp->ratelist);
 817 +       kfree(msp);
 818 +}
 819 +
 820 +static void *
 821 +minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 822 +{
 823 +       return mac80211_minstrel.alloc(hw, debugfsdir);
 824 +}
 825 +
 826 +static void
 827 +minstrel_ht_free(void *priv)
 828 +{
 829 +       mac80211_minstrel.free(priv);
 830 +}
 831 +
 832 +static struct rate_control_ops mac80211_minstrel_ht = {
 833 +       .name = "minstrel_ht",
 834 +       .tx_status = minstrel_ht_tx_status,
 835 +       .get_rate = minstrel_ht_get_rate,
 836 +       .rate_init = minstrel_ht_rate_init,
 837 +       .rate_update = minstrel_ht_rate_update,
 838 +       .alloc_sta = minstrel_ht_alloc_sta,
 839 +       .free_sta = minstrel_ht_free_sta,
 840 +       .alloc = minstrel_ht_alloc,
 841 +       .free = minstrel_ht_free,
 842 +#ifdef CONFIG_MAC80211_DEBUGFS
 843 +       .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
 844 +       .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
 845 +#endif
 846 +};
 847 +
 848 +
 849 +static void
 850 +init_sample_table(void)
 851 +{
 852 +       int col, i, new_idx;
 853 +       u8 rnd[MCS_GROUP_RATES];
 854 +
 855 +       memset(sample_table, 0xff, sizeof(sample_table));
 856 +       for (col = 0; col < SAMPLE_COLUMNS; col++) {
 857 +               for (i = 0; i < MCS_GROUP_RATES; i++) {
 858 +                       get_random_bytes(rnd, sizeof(rnd));
 859 +                       new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
 860 +
 861 +                       while (sample_table[col][new_idx] != 0xff)
 862 +                               new_idx = (new_idx + 1) % MCS_GROUP_RATES;
 863 +
 864 +                       sample_table[col][new_idx] = i;
 865 +               }
 866 +       }
 867 +}
 868 +
 869 +int __init
 870 +rc80211_minstrel_ht_init(void)
 871 +{
 872 +       init_sample_table();
 873 +       return ieee80211_rate_control_register(&mac80211_minstrel_ht);
 874 +}
 875 +
 876 +void
 877 +rc80211_minstrel_ht_exit(void)
 878 +{
 879 +       ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
 880 +}
 881 --- /dev/null
 882 +++ b/net/mac80211/rc80211_minstrel_ht.h
 883 @@ -0,0 +1,121 @@
 884 +/*
 885 + * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
 886 + *
 887 + * This program is free software; you can redistribute it and/or modify
 888 + * it under the terms of the GNU General Public License version 2 as
 889 + * published by the Free Software Foundation.
 890 + */
 891 +
 892 +#ifndef __RC_MINSTREL_HT_H
 893 +#define __RC_MINSTREL_HT_H
 894 +
 895 +/*
 896 + * maximum number of spatial streams to make use of
 897 + * set this value to 3 once we have drivers that support it
 898 + */
 899 +#define MINSTREL_MAX_STREAMS   2
 900 +#define MINSTREL_STREAM_GROUPS 4
 901 +
 902 +/* scaled fraction values */
 903 +#define MINSTREL_SCALE 16
 904 +#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
 905 +#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
 906 +
 907 +#define MCS_GROUP_RATES        8
 908 +
 909 +struct mcs_group {
 910 +       u32 flags;
 911 +       unsigned int streams;
 912 +       unsigned int duration[MCS_GROUP_RATES];
 913 +};
 914 +
 915 +struct minstrel_rate_stats {
 916 +       /* current / last sampling period attempts/success counters */
 917 +       unsigned int attempts, last_attempts;
 918 +       unsigned int success, last_success;
 919 +
 920 +       /* total attempts/success counters */
 921 +       u64 att_hist, succ_hist;
 922 +
 923 +       /* current throughput */
 924 +       unsigned int cur_tp;
 925 +
 926 +       /* packet delivery probabilities */
 927 +       unsigned int cur_prob, probability;
 928 +
 929 +       /* maximum retry counts */
 930 +       unsigned int retry_count;
 931 +       unsigned int retry_count_rtscts;
 932 +
 933 +       bool retry_updated;
 934 +       u8 sample_skipped;
 935 +};
 936 +
 937 +struct minstrel_mcs_group_data {
 938 +       u8 index;
 939 +       u8 column;
 940 +
 941 +       /* bitfield of supported MCS rates of this group */
 942 +       u8 supported;
 943 +
 944 +       /* selected primary rates */
 945 +       unsigned int max_tp_rate;
 946 +       unsigned int max_tp_rate2;
 947 +       unsigned int max_prob_rate;
 948 +
 949 +       /* MCS rate statistics */
 950 +       struct minstrel_rate_stats rates[MCS_GROUP_RATES];
 951 +};
 952 +
 953 +struct minstrel_ht_sta {
 954 +       /* ampdu length average (EWMA) */
 955 +       unsigned int avg_ampdu_len;
 956 +
 957 +       /* best throughput rate */
 958 +       unsigned int max_tp_rate;
 959 +
 960 +       /* second best throughput rate */
 961 +       unsigned int max_tp_rate2;
 962 +
 963 +       /* best probability rate */
 964 +       unsigned int max_prob_rate;
 965 +
 966 +       /* time of last status update */
 967 +       unsigned long stats_update;
 968 +
 969 +       /* overhead time in usec for each frame */
 970 +       unsigned int overhead;
 971 +       unsigned int overhead_rtscts;
 972 +
 973 +       unsigned int total_packets;
 974 +       unsigned int sample_packets;
 975 +
 976 +       u8 sample_wait;
 977 +       u8 sample_tries;
 978 +       u8 sample_count;
 979 +       u8 sample_slow;
 980 +
 981 +       /* current MCS group to be sampled */
 982 +       u8 sample_group;
 983 +
 984 +       /* MCS rate group info and statistics */
 985 +       struct minstrel_mcs_group_data groups[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS];
 986 +};
 987 +
 988 +struct minstrel_ht_sta_priv {
 989 +       union {
 990 +               struct minstrel_ht_sta ht;
 991 +               struct minstrel_sta_info legacy;
 992 +       };
 993 +#ifdef CONFIG_MAC80211_DEBUGFS
 994 +       struct dentry *dbg_stats;
 995 +#endif
 996 +       void *ratelist;
 997 +       void *sample_table;
 998 +       bool is_ht;
 999 +};
1000 +
1001 +void minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
1002 +void minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta);
1003 +
1004 +#endif
1005 --- /dev/null
1006 +++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
1007 @@ -0,0 +1,120 @@
1008 +/*
1009 + * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
1010 + *
1011 + * This program is free software; you can redistribute it and/or modify
1012 + * it under the terms of the GNU General Public License version 2 as
1013 + * published by the Free Software Foundation.
1014 + */
1015 +#include <linux/netdevice.h>
1016 +#include <linux/types.h>
1017 +#include <linux/skbuff.h>
1018 +#include <linux/debugfs.h>
1019 +#include <linux/ieee80211.h>
1020 +#include <net/mac80211.h>
1021 +#include "rc80211_minstrel.h"
1022 +#include "rc80211_minstrel_ht.h"
1023 +
1024 +extern const struct mcs_group minstrel_mcs_groups[];
1025 +
1026 +static int
1027 +minstrel_ht_stats_open(struct inode *inode, struct file *file)
1028 +{
1029 +       struct minstrel_ht_sta_priv *msp = inode->i_private;
1030 +       struct minstrel_ht_sta *mi = &msp->ht;
1031 +       struct minstrel_debugfs_info *ms;
1032 +       unsigned int i, j, tp, prob, eprob;
1033 +       char *p;
1034 +       int ret;
1035 +
1036 +       if (!msp->is_ht) {
1037 +               inode->i_private = &msp->legacy;
1038 +               ret = minstrel_stats_open(inode, file);
1039 +               inode->i_private = msp;
1040 +               return ret;
1041 +       }
1042 +
1043 +       ms = kmalloc(sizeof(*ms) + 8192, GFP_KERNEL);
1044 +       if (!ms)
1045 +               return -ENOMEM;
1046 +
1047 +       file->private_data = ms;
1048 +       p = ms->buf;
1049 +       p += sprintf(p, "type      rate     throughput  ewma prob   this prob  "
1050 +                       "this succ/attempt   success    attempts\n");
1051 +       for (i = 0; i < MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS; i++) {
1052 +               char htmode = '2';
1053 +               char gimode = 'L';
1054 +
1055 +               if (!mi->groups[i].supported)
1056 +                       continue;
1057 +
1058 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1059 +                       htmode = '4';
1060 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI)
1061 +                       gimode = 'S';
1062 +
1063 +               for (j = 0; j < MCS_GROUP_RATES; j++) {
1064 +                       struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
1065 +                       int idx = i * MCS_GROUP_RATES + j;
1066 +
1067 +                       if (!(mi->groups[i].supported & BIT(j)))
1068 +                               continue;
1069 +
1070 +                       p += sprintf(p, "HT%c0/%cGI ", htmode, gimode);
1071 +
1072 +                       *(p++) = (idx == mi->max_tp_rate) ? 'T' : ' ';
1073 +                       *(p++) = (idx == mi->max_tp_rate2) ? 't' : ' ';
1074 +                       *(p++) = (idx == mi->max_prob_rate) ? 'P' : ' ';
1075 +                       p += sprintf(p, "MCS%-2u", (minstrel_mcs_groups[i].streams - 1) *
1076 +                                       MCS_GROUP_RATES + j);
1077 +
1078 +                       tp = mr->cur_tp / 10;
1079 +                       prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
1080 +                       eprob = MINSTREL_TRUNC(mr->probability * 1000);
1081 +
1082 +                       p += sprintf(p, "  %6u.%1u   %6u.%1u   %6u.%1u        "
1083 +                                       "%3u(%3u)   %8llu    %8llu\n",
1084 +                                       tp / 10, tp % 10,
1085 +                                       eprob / 10, eprob % 10,
1086 +                                       prob / 10, prob % 10,
1087 +                                       mr->last_success,
1088 +                                       mr->last_attempts,
1089 +                                       (unsigned long long)mr->succ_hist,
1090 +                                       (unsigned long long)mr->att_hist);
1091 +               }
1092 +       }
1093 +       p += sprintf(p, "\nTotal packet count::    ideal %d      "
1094 +                       "lookaround %d\n",
1095 +                       max(0, (int) mi->total_packets - (int) mi->sample_packets),
1096 +                       mi->sample_packets);
1097 +       p += sprintf(p, "Average A-MPDU length: %d.%d\n",
1098 +               MINSTREL_TRUNC(mi->avg_ampdu_len),
1099 +               MINSTREL_TRUNC(mi->avg_ampdu_len * 10) % 10);
1100 +       ms->len = p - ms->buf;
1101 +
1102 +       return 0;
1103 +}
1104 +
1105 +static const struct file_operations minstrel_ht_stat_fops = {
1106 +       .owner = THIS_MODULE,
1107 +       .open = minstrel_ht_stats_open,
1108 +       .read = minstrel_stats_read,
1109 +       .release = minstrel_stats_release,
1110 +};
1111 +
1112 +void
1113 +minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
1114 +{
1115 +       struct minstrel_ht_sta_priv *msp = priv_sta;
1116 +
1117 +       msp->dbg_stats = debugfs_create_file("rc_stats", S_IRUGO, dir, msp,
1118 +                       &minstrel_ht_stat_fops);
1119 +}
1120 +
1121 +void
1122 +minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta)
1123 +{
1124 +       struct minstrel_ht_sta_priv *msp = priv_sta;
1125 +
1126 +       debugfs_remove(msp->dbg_stats);
1127 +}