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 +1,800 @@
  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_count = 0;
 266 +       mi->max_tp_rate = 0;
 267 +       mi->max_tp_rate2 = 0;
 268 +       mi->max_prob_rate = 0;
 269 +
 270 +       for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 271 +               cur_prob = 0;
 272 +               cur_prob_tp = 0;
 273 +               cur_tp = 0;
 274 +               cur_tp2 = 0;
 275 +
 276 +               mg = &mi->groups[group];
 277 +               if (!mg->supported)
 278 +                       continue;
 279 +
 280 +               mg->max_tp_rate = 0;
 281 +               mg->max_tp_rate2 = 0;
 282 +               mg->max_prob_rate = 0;
 283 +               mi->sample_count++;
 284 +
 285 +               for (i = 0; i < MCS_GROUP_RATES; i++) {
 286 +                       if (!(mg->supported & BIT(i)))
 287 +                               continue;
 288 +
 289 +                       mr = &mg->rates[i];
 290 +                       mr->retry_updated = false;
 291 +                       index = MCS_GROUP_RATES * group + i;
 292 +                       minstrel_calc_rate_ewma(mp, mr);
 293 +                       minstrel_ht_calc_tp(mp, mi, group, i);
 294 +
 295 +                       if (!mr->cur_tp)
 296 +                               continue;
 297 +
 298 +                       /* ignore the lowest rate of each single-stream group */
 299 +                       if (!i && minstrel_mcs_groups[group].streams == 1)
 300 +                               continue;
 301 +
 302 +                       if ((mr->cur_tp > cur_prob_tp && mr->probability >
 303 +                            MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
 304 +                               mg->max_prob_rate = index;
 305 +                               cur_prob = mr->probability;
 306 +                       }
 307 +
 308 +                       if (mr->cur_tp > cur_tp) {
 309 +                               swap(index, mg->max_tp_rate);
 310 +                               cur_tp = mr->cur_tp;
 311 +                               mr = minstrel_get_ratestats(mi, index);
 312 +                       }
 313 +
 314 +                       if (index >= mg->max_tp_rate)
 315 +                               continue;
 316 +
 317 +                       if (mr->cur_tp > cur_tp2) {
 318 +                               mg->max_tp_rate2 = index;
 319 +                               cur_tp2 = mr->cur_tp;
 320 +                       }
 321 +               }
 322 +       }
 323 +
 324 +       /* try to sample up to half of the availble rates during each interval */
 325 +       mi->sample_count *= 4;
 326 +
 327 +       cur_prob = 0;
 328 +       cur_prob_tp = 0;
 329 +       cur_tp = 0;
 330 +       cur_tp2 = 0;
 331 +       for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 332 +               mg = &mi->groups[group];
 333 +               if (!mg->supported)
 334 +                       continue;
 335 +
 336 +               mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
 337 +               if (cur_prob_tp < mr->cur_tp &&
 338 +                   minstrel_mcs_groups[group].streams == 1) {
 339 +                       mi->max_prob_rate = mg->max_prob_rate;
 340 +                       cur_prob = mr->cur_prob;
 341 +               }
 342 +
 343 +               mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
 344 +               if (cur_tp < mr->cur_tp) {
 345 +                       mi->max_tp_rate = mg->max_tp_rate;
 346 +                       cur_tp = mr->cur_tp;
 347 +               }
 348 +
 349 +               mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
 350 +               if (cur_tp2 < mr->cur_tp) {
 351 +                       mi->max_tp_rate2 = mg->max_tp_rate2;
 352 +                       cur_tp2 = mr->cur_tp;
 353 +               }
 354 +       }
 355 +
 356 +       mi->stats_update = jiffies;
 357 +}
 358 +
 359 +static bool
 360 +minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
 361 +{
 362 +       if (!rate->count)
 363 +               return false;
 364 +
 365 +       if (rate->idx < 0)
 366 +               return false;
 367 +
 368 +       return !!(rate->flags & IEEE80211_TX_RC_MCS);
 369 +}
 370 +
 371 +static void
 372 +minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
 373 +{
 374 +       struct minstrel_mcs_group_data *mg;
 375 +
 376 +       for (;;) {
 377 +               mi->sample_group++;
 378 +               mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
 379 +               mg = &mi->groups[mi->sample_group];
 380 +
 381 +               if (!mg->supported)
 382 +                       continue;
 383 +
 384 +               if (++mg->index > MCS_GROUP_RATES) {
 385 +                       mg->index = 0;
 386 +                       if (++mg->column > ARRAY_SIZE(sample_table))
 387 +                               mg->column = 0;
 388 +               }
 389 +               break;
 390 +       }
 391 +}
 392 +
 393 +static void
 394 +minstrel_downgrade_rate(struct minstrel_ht_sta *mi, int *idx, bool primary)
 395 +{
 396 +       int group, orig_group;
 397 +
 398 +       orig_group = group = *idx / MCS_GROUP_RATES;
 399 +       while (group > 0) {
 400 +               group--;
 401 +
 402 +               if (!mi->groups[group].supported)
 403 +                       continue;
 404 +
 405 +               if (minstrel_mcs_groups[group].streams >
 406 +                   minstrel_mcs_groups[orig_group].streams)
 407 +                       continue;
 408 +
 409 +               if (primary)
 410 +                       *idx = mi->groups[group].max_tp_rate;
 411 +               else
 412 +                       *idx = mi->groups[group].max_tp_rate2;
 413 +               break;
 414 +       }
 415 +}
 416 +
 417 +
 418 +static void
 419 +minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
 420 +                      struct ieee80211_sta *sta, void *priv_sta,
 421 +                      struct sk_buff *skb)
 422 +{
 423 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 424 +       struct minstrel_ht_sta *mi = &msp->ht;
 425 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 426 +       struct ieee80211_tx_rate *ar = info->status.rates;
 427 +       struct minstrel_rate_stats *rate, *rate2;
 428 +       struct minstrel_priv *mp = priv;
 429 +       bool last = false;
 430 +       int group;
 431 +       int i = 0;
 432 +
 433 +       if (!msp->is_ht)
 434 +               return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
 435 +
 436 +       /* This packet was aggregated but doesn't carry status info */
 437 +       if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
 438 +           !(info->flags & IEEE80211_TX_STAT_AMPDU))
 439 +               return;
 440 +
 441 +       if (!info->status.ampdu_len) {
 442 +               info->status.ampdu_ack_len = 1;
 443 +               info->status.ampdu_len = 1;
 444 +       }
 445 +
 446 +       mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
 447 +               MINSTREL_FRAC(info->status.ampdu_len, 1), 90);
 448 +
 449 +       if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
 450 +               mi->sample_wait = 4 + MINSTREL_TRUNC(mi->avg_ampdu_len);
 451 +               mi->sample_tries = 3;
 452 +               mi->sample_count--;
 453 +       }
 454 +
 455 +       if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) {
 456 +               mi->sample_packets += info->status.ampdu_len;
 457 +               minstrel_next_sample_idx(mi);
 458 +       }
 459 +
 460 +       for (i = 0; !last; i++) {
 461 +               last = (i == IEEE80211_TX_MAX_RATES - 1) ||
 462 +                      !minstrel_ht_txstat_valid(&ar[i + 1]);
 463 +
 464 +               if (!minstrel_ht_txstat_valid(&ar[i]))
 465 +                       break;
 466 +
 467 +               group = minstrel_ht_get_group_idx(&ar[i]);
 468 +               rate = &mi->groups[group].rates[ar[i].idx % 8];
 469 +
 470 +               if (last && (info->flags & IEEE80211_TX_STAT_ACK))
 471 +                       rate->success += info->status.ampdu_ack_len;
 472 +
 473 +               rate->attempts += ar[i].count * info->status.ampdu_len;
 474 +       }
 475 +
 476 +       /*
 477 +        * check for sudden death of spatial multiplexing,
 478 +        * downgrade to a lower number of streams if necessary.
 479 +        */
 480 +       rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
 481 +       if (MINSTREL_FRAC(rate->success, rate->attempts) <
 482 +           MINSTREL_FRAC(20, 100) && rate->attempts > 30)
 483 +               minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
 484 +
 485 +       rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
 486 +       if (MINSTREL_FRAC(rate->success, rate->attempts) <
 487 +           MINSTREL_FRAC(20, 100) && rate->attempts > 30)
 488 +               minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
 489 +
 490 +       if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000))
 491 +               minstrel_ht_update_stats(mp, mi);
 492 +}
 493 +
 494 +static void
 495 +minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 496 +                         int index)
 497 +{
 498 +       struct minstrel_rate_stats *mr;
 499 +       const struct mcs_group *group;
 500 +       unsigned int tx_time, tx_time_rtscts, tx_time_data;
 501 +       unsigned int cw = mp->cw_min;
 502 +       unsigned int t_slot = 9; /* FIXME */
 503 +       unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
 504 +
 505 +       mr = minstrel_get_ratestats(mi, index);
 506 +       if (mr->probability < MINSTREL_FRAC(1, 10)) {
 507 +               mr->retry_count = 1;
 508 +               mr->retry_count_rtscts = 1;
 509 +               return;
 510 +       }
 511 +
 512 +       mr->retry_count = 2;
 513 +       mr->retry_count_rtscts = 2;
 514 +       mr->retry_updated = true;
 515 +
 516 +       group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
 517 +       tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
 518 +       tx_time = 2 * (t_slot + mi->overhead + tx_time_data);
 519 +       tx_time_rtscts = 2 * (t_slot + mi->overhead_rtscts + tx_time_data);
 520 +       do {
 521 +               cw = (cw << 1) | 1;
 522 +               cw = min(cw, mp->cw_max);
 523 +               tx_time += cw + t_slot + mi->overhead;
 524 +               tx_time_rtscts += cw + t_slot + mi->overhead_rtscts;
 525 +               if (tx_time_rtscts < mp->segment_size)
 526 +                       mr->retry_count_rtscts++;
 527 +       } while ((tx_time < mp->segment_size) &&
 528 +                (++mr->retry_count < mp->max_retry));
 529 +}
 530 +
 531 +
 532 +static void
 533 +minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 534 +                     struct ieee80211_tx_rate *rate, int index,
 535 +                     struct ieee80211_tx_rate_control *txrc,
 536 +                     bool sample, bool rtscts)
 537 +{
 538 +       const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
 539 +       struct minstrel_rate_stats *mr;
 540 +
 541 +       mr = minstrel_get_ratestats(mi, index);
 542 +       if (!mr->retry_updated)
 543 +               minstrel_calc_retransmit(mp, mi, index);
 544 +
 545 +       if (rtscts)
 546 +               rate->count = mr->retry_count_rtscts;
 547 +       else
 548 +               rate->count = mr->retry_count;
 549 +
 550 +       rate->flags = IEEE80211_TX_RC_MCS | group->flags;
 551 +       if (txrc->short_preamble)
 552 +               rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 553 +       if (txrc->rts || rtscts)
 554 +               rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 555 +       rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
 556 +}
 557 +
 558 +static inline int
 559 +minstrel_get_duration(int index)
 560 +{
 561 +       const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
 562 +       return group->duration[index % MCS_GROUP_RATES];
 563 +}
 564 +
 565 +static int
 566 +minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 567 +{
 568 +       struct minstrel_rate_stats *mr;
 569 +       struct minstrel_mcs_group_data *mg;
 570 +       int sample_idx = 0;
 571 +
 572 +       if (mi->sample_wait > 0) {
 573 +               mi->sample_wait--;
 574 +               return -1;
 575 +       }
 576 +
 577 +       if (!mi->sample_tries)
 578 +               return -1;
 579 +
 580 +       mi->sample_tries--;
 581 +       mg = &mi->groups[mi->sample_group];
 582 +       sample_idx = sample_table[mg->column][mg->index];
 583 +       mr = &mg->rates[sample_idx];
 584 +       sample_idx += mi->sample_group * MCS_GROUP_RATES;
 585 +
 586 +       /*
 587 +        * When not using MRR, do not sample if the probability is already
 588 +        * higher than 95% to avoid wasting airtime
 589 +        */
 590 +       if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
 591 +               goto next;
 592 +
 593 +       /*
 594 +        * Make sure that lower rates get sampled only occasionally,
 595 +        * if the link is working perfectly.
 596 +        */
 597 +       if (minstrel_get_duration(sample_idx) >
 598 +           minstrel_get_duration(mi->max_tp_rate) &&
 599 +           mr->sample_skipped < 10)
 600 +               goto next;
 601 +
 602 +       return sample_idx;
 603 +
 604 +next:
 605 +       minstrel_next_sample_idx(mi);
 606 +       return -1;
 607 +}
 608 +
 609 +static void
 610 +minstrel_aggr_check(struct minstrel_priv *mp, struct ieee80211_sta *pubsta, struct sk_buff *skb)
 611 +{
 612 +       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 613 +       struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 614 +       u16 tid;
 615 +
 616 +       if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
 617 +               return;
 618 +
 619 +       if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
 620 +               return;
 621 +
 622 +       tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 623 +       if (likely(sta->ampdu_mlme.tid_state_tx[tid] != HT_AGG_STATE_IDLE))
 624 +               return;
 625 +
 626 +       ieee80211_start_tx_ba_session(pubsta, tid);
 627 +}
 628 +
 629 +static void
 630 +minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
 631 +                     struct ieee80211_tx_rate_control *txrc)
 632 +{
 633 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 634 +       struct ieee80211_tx_rate *ar = info->status.rates;
 635 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 636 +       struct minstrel_ht_sta *mi = &msp->ht;
 637 +       struct minstrel_priv *mp = priv;
 638 +       int sample_idx;
 639 +
 640 +       if (rate_control_send_low(sta, priv_sta, txrc))
 641 +               return;
 642 +
 643 +       if (!msp->is_ht)
 644 +               return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
 645 +
 646 +       minstrel_aggr_check(mp, sta, txrc->skb);
 647 +
 648 +       sample_idx = minstrel_get_sample_rate(mp, mi);
 649 +       if (sample_idx >= 0) {
 650 +               minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
 651 +                       txrc, true, false);
 652 +               minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
 653 +                       txrc, false, true);
 654 +               info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
 655 +       } else {
 656 +               minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
 657 +                       txrc, false, false);
 658 +               minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
 659 +                       txrc, false, true);
 660 +       }
 661 +       minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate, txrc, false, true);
 662 +
 663 +       ar[3].count = 0;
 664 +       ar[3].idx = -1;
 665 +
 666 +       mi->total_packets++;
 667 +
 668 +       /* wraparound */
 669 +       if (mi->total_packets == ~0) {
 670 +               mi->total_packets = 0;
 671 +               mi->sample_packets = 0;
 672 +       }
 673 +}
 674 +
 675 +static void
 676 +minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
 677 +                        struct ieee80211_sta *sta, void *priv_sta,
 678 +                       enum nl80211_channel_type oper_chan_type)
 679 +{
 680 +       struct minstrel_priv *mp = priv;
 681 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 682 +       struct minstrel_ht_sta *mi = &msp->ht;
 683 +       struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
 684 +       struct ieee80211_local *local = hw_to_local(mp->hw);
 685 +       u16 sta_cap = sta->ht_cap.cap;
 686 +       int ack_dur;
 687 +       int i;
 688 +
 689 +       /* fall back to the old minstrel for legacy stations */
 690 +       if (sta && !sta->ht_cap.ht_supported) {
 691 +               msp->is_ht = false;
 692 +               memset(&msp->legacy, 0, sizeof(msp->legacy));
 693 +               msp->legacy.r = msp->ratelist;
 694 +               msp->legacy.sample_table = msp->sample_table;
 695 +               return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
 696 +       }
 697 +
 698 +       BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
 699 +               MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
 700 +
 701 +       msp->is_ht = true;
 702 +       memset(mi, 0, sizeof(*mi));
 703 +       mi->stats_update = jiffies;
 704 +
 705 +       ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1);
 706 +       mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur;
 707 +       mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
 708 +
 709 +       mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
 710 +
 711 +       /* When using MRR, sample more on the first attempt, without delay */
 712 +       if (mp->has_mrr) {
 713 +               mi->sample_count = 16;
 714 +               mi->sample_wait = 0;
 715 +       } else {
 716 +               mi->sample_count = 8;
 717 +               mi->sample_wait = 8;
 718 +       }
 719 +       mi->sample_tries = 4;
 720 +
 721 +       if (oper_chan_type != NL80211_CHAN_HT40MINUS &&
 722 +           oper_chan_type != NL80211_CHAN_HT40PLUS)
 723 +               sta_cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 724 +
 725 +       for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
 726 +               u16 req = 0;
 727 +
 728 +               mi->groups[i].supported = 0;
 729 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
 730 +                       if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 731 +                               req |= IEEE80211_HT_CAP_SGI_40;
 732 +                       else
 733 +                               req |= IEEE80211_HT_CAP_SGI_20;
 734 +               }
 735 +
 736 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 737 +                       req |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 738 +
 739 +               if ((sta_cap & req) != req)
 740 +                       continue;
 741 +
 742 +               mi->groups[i].supported =
 743 +                       mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
 744 +       }
 745 +}
 746 +
 747 +static void
 748 +minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
 749 +                      struct ieee80211_sta *sta, void *priv_sta)
 750 +{
 751 +       struct minstrel_priv *mp = priv;
 752 +
 753 +       minstrel_ht_update_caps(priv, sband, sta, priv_sta, mp->hw->conf.channel_type);
 754 +}
 755 +
 756 +static void
 757 +minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
 758 +                        struct ieee80211_sta *sta, void *priv_sta,
 759 +                        u32 changed, enum nl80211_channel_type oper_chan_type)
 760 +{
 761 +       minstrel_ht_update_caps(priv, sband, sta, priv_sta, oper_chan_type);
 762 +}
 763 +
 764 +static void *
 765 +minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 766 +{
 767 +       struct ieee80211_supported_band *sband;
 768 +       struct minstrel_ht_sta_priv *msp;
 769 +       struct minstrel_priv *mp = priv;
 770 +       struct ieee80211_hw *hw = mp->hw;
 771 +       int max_rates = 0;
 772 +       int i;
 773 +
 774 +       for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
 775 +               sband = hw->wiphy->bands[i];
 776 +               if (sband && sband->n_bitrates > max_rates)
 777 +                       max_rates = sband->n_bitrates;
 778 +       }
 779 +
 780 +       msp = kzalloc(sizeof(struct minstrel_ht_sta), gfp);
 781 +       if (!msp)
 782 +               return NULL;
 783 +
 784 +       msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
 785 +       if (!msp->ratelist)
 786 +               goto error;
 787 +
 788 +       msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
 789 +       if (!msp->sample_table)
 790 +               goto error1;
 791 +
 792 +       return msp;
 793 +
 794 +error1:
 795 +       kfree(msp->sample_table);
 796 +error:
 797 +       kfree(msp);
 798 +       return NULL;
 799 +}
 800 +
 801 +static void
 802 +minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
 803 +{
 804 +       struct minstrel_ht_sta_priv *msp = priv_sta;
 805 +
 806 +       kfree(msp->sample_table);
 807 +       kfree(msp->ratelist);
 808 +       kfree(msp);
 809 +}
 810 +
 811 +static void *
 812 +minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 813 +{
 814 +       return mac80211_minstrel.alloc(hw, debugfsdir);
 815 +}
 816 +
 817 +static void
 818 +minstrel_ht_free(void *priv)
 819 +{
 820 +       mac80211_minstrel.free(priv);
 821 +}
 822 +
 823 +static struct rate_control_ops mac80211_minstrel_ht = {
 824 +       .name = "minstrel_ht",
 825 +       .tx_status = minstrel_ht_tx_status,
 826 +       .get_rate = minstrel_ht_get_rate,
 827 +       .rate_init = minstrel_ht_rate_init,
 828 +       .rate_update = minstrel_ht_rate_update,
 829 +       .alloc_sta = minstrel_ht_alloc_sta,
 830 +       .free_sta = minstrel_ht_free_sta,
 831 +       .alloc = minstrel_ht_alloc,
 832 +       .free = minstrel_ht_free,
 833 +#ifdef CONFIG_MAC80211_DEBUGFS
 834 +       .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
 835 +       .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
 836 +#endif
 837 +};
 838 +
 839 +
 840 +static void
 841 +init_sample_table(void)
 842 +{
 843 +       int col, i, new_idx;
 844 +       u8 rnd[MCS_GROUP_RATES];
 845 +
 846 +       memset(sample_table, 0xff, sizeof(sample_table));
 847 +       for (col = 0; col < SAMPLE_COLUMNS; col++) {
 848 +               for (i = 0; i < MCS_GROUP_RATES; i++) {
 849 +                       get_random_bytes(rnd, sizeof(rnd));
 850 +                       new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
 851 +
 852 +                       while (sample_table[col][new_idx] != 0xff)
 853 +                               new_idx = (new_idx + 1) % MCS_GROUP_RATES;
 854 +
 855 +                       sample_table[col][new_idx] = i;
 856 +               }
 857 +       }
 858 +}
 859 +
 860 +int __init
 861 +rc80211_minstrel_ht_init(void)
 862 +{
 863 +       init_sample_table();
 864 +       return ieee80211_rate_control_register(&mac80211_minstrel_ht);
 865 +}
 866 +
 867 +void
 868 +rc80211_minstrel_ht_exit(void)
 869 +{
 870 +       ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
 871 +}
 872 --- /dev/null
 873 +++ b/net/mac80211/rc80211_minstrel_ht.h
 874 @@ -0,0 +1,120 @@
 875 +/*
 876 + * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
 877 + *
 878 + * This program is free software; you can redistribute it and/or modify
 879 + * it under the terms of the GNU General Public License version 2 as
 880 + * published by the Free Software Foundation.
 881 + */
 882 +
 883 +#ifndef __RC_MINSTREL_HT_H
 884 +#define __RC_MINSTREL_HT_H
 885 +
 886 +/*
 887 + * maximum number of spatial streams to make use of
 888 + * set this value to 3 once we have drivers that support it
 889 + */
 890 +#define MINSTREL_MAX_STREAMS   2
 891 +#define MINSTREL_STREAM_GROUPS 4
 892 +
 893 +/* scaled fraction values */
 894 +#define MINSTREL_SCALE 16
 895 +#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
 896 +#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
 897 +
 898 +#define MCS_GROUP_RATES        8
 899 +
 900 +struct mcs_group {
 901 +       u32 flags;
 902 +       unsigned int streams;
 903 +       unsigned int duration[MCS_GROUP_RATES];
 904 +};
 905 +
 906 +struct minstrel_rate_stats {
 907 +       /* current / last sampling period attempts/success counters */
 908 +       unsigned int attempts, last_attempts;
 909 +       unsigned int success, last_success;
 910 +
 911 +       /* total attempts/success counters */
 912 +       u64 att_hist, succ_hist;
 913 +
 914 +       /* current throughput */
 915 +       unsigned int cur_tp;
 916 +
 917 +       /* packet delivery probabilities */
 918 +       unsigned int cur_prob, probability;
 919 +
 920 +       /* maximum retry counts */
 921 +       unsigned int retry_count;
 922 +       unsigned int retry_count_rtscts;
 923 +
 924 +       bool retry_updated;
 925 +       u8 sample_skipped;
 926 +};
 927 +
 928 +struct minstrel_mcs_group_data {
 929 +       u8 index;
 930 +       u8 column;
 931 +
 932 +       /* bitfield of supported MCS rates of this group */
 933 +       u8 supported;
 934 +
 935 +       /* selected primary rates */
 936 +       unsigned int max_tp_rate;
 937 +       unsigned int max_tp_rate2;
 938 +       unsigned int max_prob_rate;
 939 +
 940 +       /* MCS rate statistics */
 941 +       struct minstrel_rate_stats rates[MCS_GROUP_RATES];
 942 +};
 943 +
 944 +struct minstrel_ht_sta {
 945 +       /* ampdu length average (EWMA) */
 946 +       unsigned int avg_ampdu_len;
 947 +
 948 +       /* best throughput rate */
 949 +       unsigned int max_tp_rate;
 950 +
 951 +       /* second best throughput rate */
 952 +       unsigned int max_tp_rate2;
 953 +
 954 +       /* best probability rate */
 955 +       unsigned int max_prob_rate;
 956 +
 957 +       /* time of last status update */
 958 +       unsigned long stats_update;
 959 +
 960 +       /* overhead time in usec for each frame */
 961 +       unsigned int overhead;
 962 +       unsigned int overhead_rtscts;
 963 +
 964 +       unsigned int total_packets;
 965 +       unsigned int sample_packets;
 966 +
 967 +       u8 sample_wait;
 968 +       u8 sample_tries;
 969 +       u8 sample_count;
 970 +
 971 +       /* current MCS group to be sampled */
 972 +       u8 sample_group;
 973 +
 974 +       /* MCS rate group info and statistics */
 975 +       struct minstrel_mcs_group_data groups[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS];
 976 +};
 977 +
 978 +struct minstrel_ht_sta_priv {
 979 +       union {
 980 +               struct minstrel_ht_sta ht;
 981 +               struct minstrel_sta_info legacy;
 982 +       };
 983 +#ifdef CONFIG_MAC80211_DEBUGFS
 984 +       struct dentry *dbg_stats;
 985 +#endif
 986 +       void *ratelist;
 987 +       void *sample_table;
 988 +       bool is_ht;
 989 +};
 990 +
 991 +void minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 992 +void minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta);
 993 +
 994 +#endif
 995 --- /dev/null
 996 +++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
 997 @@ -0,0 +1,120 @@
 998 +/*
 999 + * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
1000 + *
1001 + * This program is free software; you can redistribute it and/or modify
1002 + * it under the terms of the GNU General Public License version 2 as
1003 + * published by the Free Software Foundation.
1004 + */
1005 +#include <linux/netdevice.h>
1006 +#include <linux/types.h>
1007 +#include <linux/skbuff.h>
1008 +#include <linux/debugfs.h>
1009 +#include <linux/ieee80211.h>
1010 +#include <net/mac80211.h>
1011 +#include "rc80211_minstrel.h"
1012 +#include "rc80211_minstrel_ht.h"
1013 +
1014 +extern const struct mcs_group minstrel_mcs_groups[];
1015 +
1016 +static int
1017 +minstrel_ht_stats_open(struct inode *inode, struct file *file)
1018 +{
1019 +       struct minstrel_ht_sta_priv *msp = inode->i_private;
1020 +       struct minstrel_ht_sta *mi = &msp->ht;
1021 +       struct minstrel_debugfs_info *ms;
1022 +       unsigned int i, j, tp, prob, eprob;
1023 +       char *p;
1024 +       int ret;
1025 +
1026 +       if (!msp->is_ht) {
1027 +               inode->i_private = &msp->legacy;
1028 +               ret = minstrel_stats_open(inode, file);
1029 +               inode->i_private = msp;
1030 +               return ret;
1031 +       }
1032 +
1033 +       ms = kmalloc(sizeof(*ms) + 8192, GFP_KERNEL);
1034 +       if (!ms)
1035 +               return -ENOMEM;
1036 +
1037 +       file->private_data = ms;
1038 +       p = ms->buf;
1039 +       p += sprintf(p, "type      rate     throughput  ewma prob   this prob  "
1040 +                       "this succ/attempt   success    attempts\n");
1041 +       for (i = 0; i < MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS; i++) {
1042 +               char htmode = '2';
1043 +               char gimode = 'L';
1044 +
1045 +               if (!mi->groups[i].supported)
1046 +                       continue;
1047 +
1048 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1049 +                       htmode = '4';
1050 +               if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI)
1051 +                       gimode = 'S';
1052 +
1053 +               for (j = 0; j < MCS_GROUP_RATES; j++) {
1054 +                       struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
1055 +                       int idx = i * MCS_GROUP_RATES + j;
1056 +
1057 +                       if (!mi->groups[i].supported & BIT(j))
1058 +                               continue;
1059 +
1060 +                       p += sprintf(p, "HT%c0/%cGI ", htmode, gimode);
1061 +
1062 +                       *(p++) = (idx == mi->max_tp_rate) ? 'T' : ' ';
1063 +                       *(p++) = (idx == mi->max_tp_rate2) ? 't' : ' ';
1064 +                       *(p++) = (idx == mi->max_prob_rate) ? 'P' : ' ';
1065 +                       p += sprintf(p, "MCS%-2u", (minstrel_mcs_groups[i].streams - 1) *
1066 +                                       MCS_GROUP_RATES + j);
1067 +
1068 +                       tp = mr->cur_tp / 10;
1069 +                       prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
1070 +                       eprob = MINSTREL_TRUNC(mr->probability * 1000);
1071 +
1072 +                       p += sprintf(p, "  %6u.%1u   %6u.%1u   %6u.%1u        "
1073 +                                       "%3u(%3u)   %8llu    %8llu\n",
1074 +                                       tp / 10, tp % 10,
1075 +                                       eprob / 10, eprob % 10,
1076 +                                       prob / 10, prob % 10,
1077 +                                       mr->last_success,
1078 +                                       mr->last_attempts,
1079 +                                       (unsigned long long)mr->succ_hist,
1080 +                                       (unsigned long long)mr->att_hist);
1081 +               }
1082 +       }
1083 +       p += sprintf(p, "\nTotal packet count::    ideal %d      "
1084 +                       "lookaround %d\n",
1085 +                       max(0, (int) mi->total_packets - (int) mi->sample_packets),
1086 +                       mi->sample_packets);
1087 +       p += sprintf(p, "Average A-MPDU length: %d.%d\n",
1088 +               MINSTREL_TRUNC(mi->avg_ampdu_len),
1089 +               MINSTREL_TRUNC(mi->avg_ampdu_len * 10) % 10);
1090 +       ms->len = p - ms->buf;
1091 +
1092 +       return 0;
1093 +}
1094 +
1095 +static const struct file_operations minstrel_ht_stat_fops = {
1096 +       .owner = THIS_MODULE,
1097 +       .open = minstrel_ht_stats_open,
1098 +       .read = minstrel_stats_read,
1099 +       .release = minstrel_stats_release,
1100 +};
1101 +
1102 +void
1103 +minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
1104 +{
1105 +       struct minstrel_ht_sta_priv *msp = priv_sta;
1106 +
1107 +       msp->dbg_stats = debugfs_create_file("rc_stats", S_IRUGO, dir, msp,
1108 +                       &minstrel_ht_stat_fops);
1109 +}
1110 +
1111 +void
1112 +minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta)
1113 +{
1114 +       struct minstrel_ht_sta_priv *msp = priv_sta;
1115 +
1116 +       debugfs_remove(msp->dbg_stats);
1117 +}