package/kernel/mac80211/patches/327-mac80211-minstrel-merge-with-minstrel_ht-always-enab.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Sat, 10 Feb 2018 12:43:30 +0100
   3 Subject: [PATCH] mac80211: minstrel: merge with minstrel_ht, always enable
   4  VHT support
   5
   6 Legacy-only devices are not very common and the overhead of the extra
   7 code for HT and VHT rates is not big enough to justify all those extra
   8 lines of code to make it optional.
   9
  10 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  11 ---
  12
  13 --- a/net/mac80211/Kconfig
  14 +++ b/net/mac80211/Kconfig
  15 @@ -25,20 +25,6 @@ config MAC80211_RC_MINSTREL
  16         ---help---
  17           This option enables the 'minstrel' TX rate control algorithm
  18
  19 -config MAC80211_RC_MINSTREL_HT
  20 -       bool "Minstrel 802.11n support" if EXPERT
  21 -       depends on MAC80211_RC_MINSTREL
  22 -       default y
  23 -       ---help---
  24 -         This option enables the 'minstrel_ht' TX rate control algorithm
  25 -
  26 -config MAC80211_RC_MINSTREL_VHT
  27 -       bool "Minstrel 802.11ac support" if EXPERT
  28 -       depends on MAC80211_RC_MINSTREL_HT
  29 -       default n
  30 -       ---help---
  31 -         This option enables VHT in the 'minstrel_ht' TX rate control algorithm
  32 -
  33  choice
  34         prompt "Default rate control algorithm"
  35         depends on MAC80211_HAS_RC
  36 @@ -60,8 +46,7 @@ endchoice
  37
  38  config MAC80211_RC_DEFAULT
  39         string
  40 -       default "minstrel_ht" if MAC80211_RC_DEFAULT_MINSTREL && MAC80211_RC_MINSTREL_HT
  41 -       default "minstrel" if MAC80211_RC_DEFAULT_MINSTREL
  42 +       default "minstrel_ht" if MAC80211_RC_DEFAULT_MINSTREL
  43         default ""
  44
  45  endif
  46 --- a/net/mac80211/Makefile
  47 +++ b/net/mac80211/Makefile
  48 @@ -50,13 +50,14 @@ mac80211-$(CONFIG_PM) += pm.o
  49
  50  CFLAGS_trace.o := -I$(src)
  51
  52 -rc80211_minstrel-y := rc80211_minstrel.o
  53 -rc80211_minstrel-$(CPTCFG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o
  54 +rc80211_minstrel-y := \
  55 +       rc80211_minstrel.o \
  56 +       rc80211_minstrel_ht.o
  57
  58 -rc80211_minstrel_ht-y := rc80211_minstrel_ht.o
  59 -rc80211_minstrel_ht-$(CPTCFG_MAC80211_DEBUGFS) += rc80211_minstrel_ht_debugfs.o
  60 +rc80211_minstrel-$(CPTCFG_MAC80211_DEBUGFS) += \
  61 +       rc80211_minstrel_debugfs.o \
  62 +       rc80211_minstrel_ht_debugfs.o
  63
  64  mac80211-$(CPTCFG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)
  65 -mac80211-$(CPTCFG_MAC80211_RC_MINSTREL_HT) += $(rc80211_minstrel_ht-y)
  66
  67  ccflags-y += -DDEBUG
  68 --- a/net/mac80211/main.c
  69 +++ b/net/mac80211/main.c
  70 @@ -1252,18 +1252,12 @@ static int __init ieee80211_init(void)
  71         if (ret)
  72                 return ret;
  73
  74 -       ret = rc80211_minstrel_ht_init();
  75 -       if (ret)
  76 -               goto err_minstrel;
  77 -
  78         ret = ieee80211_iface_init();
  79         if (ret)
  80                 goto err_netdev;
  81
  82         return 0;
  83   err_netdev:
  84 -       rc80211_minstrel_ht_exit();
  85 - err_minstrel:
  86         rc80211_minstrel_exit();
  87
  88         return ret;
  89 @@ -1271,7 +1265,6 @@ static int __init ieee80211_init(void)
  90
  91  static void __exit ieee80211_exit(void)
  92  {
  93 -       rc80211_minstrel_ht_exit();
  94         rc80211_minstrel_exit();
  95
  96         ieee80211s_stop();
  97 --- a/net/mac80211/rate.h
  98 +++ b/net/mac80211/rate.h
  99 @@ -95,18 +95,5 @@ static inline void rc80211_minstrel_exit
 100  }
 101  #endif
 102
 103 -#ifdef CPTCFG_MAC80211_RC_MINSTREL_HT
 104 -int rc80211_minstrel_ht_init(void);
 105 -void rc80211_minstrel_ht_exit(void);
 106 -#else
 107 -static inline int rc80211_minstrel_ht_init(void)
 108 -{
 109 -       return 0;
 110 -}
 111 -static inline void rc80211_minstrel_ht_exit(void)
 112 -{
 113 -}
 114 -#endif
 115 -
 116
 117  #endif /* IEEE80211_RATE_H */
 118 --- a/net/mac80211/rc80211_minstrel.c
 119 +++ b/net/mac80211/rc80211_minstrel.c
 120 @@ -482,6 +482,38 @@ init_sample_table(struct minstrel_sta_in
 121  }
 122
 123  static void
 124 +minstrel_init_cck_rates(struct minstrel_priv *mp,
 125 +                       struct cfg80211_chan_def *chandef)
 126 +{
 127 +       static const int bitrates[4] = { 10, 20, 55, 110 };
 128 +       struct ieee80211_supported_band *sband;
 129 +       u32 rate_flags = ieee80211_chandef_rate_flags(chandef);
 130 +       int i, j;
 131 +
 132 +       sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
 133 +       if (!sband)
 134 +               return;
 135 +
 136 +       for (i = 0, j = 0; i < sband->n_bitrates; i++) {
 137 +               struct ieee80211_rate *rate = &sband->bitrates[i];
 138 +
 139 +               if (rate->flags & IEEE80211_RATE_ERP_G)
 140 +                       continue;
 141 +
 142 +               if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 143 +                       continue;
 144 +
 145 +               for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
 146 +                       if (rate->bitrate != bitrates[j])
 147 +                               continue;
 148 +
 149 +                       mp->cck_rates[j] = i;
 150 +                       break;
 151 +               }
 152 +       }
 153 +}
 154 +
 155 +static void
 156  minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
 157                    struct cfg80211_chan_def *chandef,
 158                    struct ieee80211_sta *sta, void *priv_sta)
 159 @@ -493,6 +525,8 @@ minstrel_rate_init(void *priv, struct ie
 160         unsigned int t_slot = 9; /* FIXME: get real slot time */
 161         u32 rate_flags;
 162
 163 +       minstrel_init_cck_rates(mp, chandef);
 164 +
 165         mi->sta = sta;
 166         mi->lowest_rix = rate_lowest_index(sband, sta);
 167         ctl_rate = &sband->bitrates[mi->lowest_rix];
 168 @@ -572,138 +606,6 @@ minstrel_rate_init(void *priv, struct ie
 169         minstrel_update_rates(mp, mi);
 170  }
 171
 172 -static void *
 173 -minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 174 -{
 175 -       struct ieee80211_supported_band *sband;
 176 -       struct minstrel_sta_info *mi;
 177 -       struct minstrel_priv *mp = priv;
 178 -       struct ieee80211_hw *hw = mp->hw;
 179 -       int max_rates = 0;
 180 -       int i;
 181 -
 182 -       mi = kzalloc(sizeof(struct minstrel_sta_info), gfp);
 183 -       if (!mi)
 184 -               return NULL;
 185 -
 186 -       for (i = 0; i < NUM_NL80211_BANDS; i++) {
 187 -               sband = hw->wiphy->bands[i];
 188 -               if (sband && sband->n_bitrates > max_rates)
 189 -                       max_rates = sband->n_bitrates;
 190 -       }
 191 -
 192 -       mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
 193 -       if (!mi->r)
 194 -               goto error;
 195 -
 196 -       mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
 197 -       if (!mi->sample_table)
 198 -               goto error1;
 199 -
 200 -       mi->last_stats_update = jiffies;
 201 -       return mi;
 202 -
 203 -error1:
 204 -       kfree(mi->r);
 205 -error:
 206 -       kfree(mi);
 207 -       return NULL;
 208 -}
 209 -
 210 -static void
 211 -minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
 212 -{
 213 -       struct minstrel_sta_info *mi = priv_sta;
 214 -
 215 -       kfree(mi->sample_table);
 216 -       kfree(mi->r);
 217 -       kfree(mi);
 218 -}
 219 -
 220 -static void
 221 -minstrel_init_cck_rates(struct minstrel_priv *mp)
 222 -{
 223 -       static const int bitrates[4] = { 10, 20, 55, 110 };
 224 -       struct ieee80211_supported_band *sband;
 225 -       u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
 226 -       int i, j;
 227 -
 228 -       sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
 229 -       if (!sband)
 230 -               return;
 231 -
 232 -       for (i = 0, j = 0; i < sband->n_bitrates; i++) {
 233 -               struct ieee80211_rate *rate = &sband->bitrates[i];
 234 -
 235 -               if (rate->flags & IEEE80211_RATE_ERP_G)
 236 -                       continue;
 237 -
 238 -               if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 239 -                       continue;
 240 -
 241 -               for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
 242 -                       if (rate->bitrate != bitrates[j])
 243 -                               continue;
 244 -
 245 -                       mp->cck_rates[j] = i;
 246 -                       break;
 247 -               }
 248 -       }
 249 -}
 250 -
 251 -static void *
 252 -minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 253 -{
 254 -       struct minstrel_priv *mp;
 255 -
 256 -       mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
 257 -       if (!mp)
 258 -               return NULL;
 259 -
 260 -       /* contention window settings
 261 -        * Just an approximation. Using the per-queue values would complicate
 262 -        * the calculations and is probably unnecessary */
 263 -       mp->cw_min = 15;
 264 -       mp->cw_max = 1023;
 265 -
 266 -       /* number of packets (in %) to use for sampling other rates
 267 -        * sample less often for non-mrr packets, because the overhead
 268 -        * is much higher than with mrr */
 269 -       mp->lookaround_rate = 5;
 270 -       mp->lookaround_rate_mrr = 10;
 271 -
 272 -       /* maximum time that the hw is allowed to stay in one MRR segment */
 273 -       mp->segment_size = 6000;
 274 -
 275 -       if (hw->max_rate_tries > 0)
 276 -               mp->max_retry = hw->max_rate_tries;
 277 -       else
 278 -               /* safe default, does not necessarily have to match hw properties */
 279 -               mp->max_retry = 7;
 280 -
 281 -       if (hw->max_rates >= 4)
 282 -               mp->has_mrr = true;
 283 -
 284 -       mp->hw = hw;
 285 -       mp->update_interval = 100;
 286 -
 287 -#ifdef CPTCFG_MAC80211_DEBUGFS
 288 -       mp->fixed_rate_idx = (u32) -1;
 289 -       debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
 290 -                          &mp->fixed_rate_idx);
 291 -#endif
 292 -
 293 -       minstrel_init_cck_rates(mp);
 294 -
 295 -       return mp;
 296 -}
 297 -
 298 -static void
 299 -minstrel_free(void *priv)
 300 -{
 301 -       kfree(priv);
 302 -}
 303 -
 304  static u32 minstrel_get_expected_throughput(void *priv_sta)
 305  {
 306         struct minstrel_sta_info *mi = priv_sta;
 307 @@ -722,29 +624,8 @@ static u32 minstrel_get_expected_through
 308  }
 309
 310  const struct rate_control_ops mac80211_minstrel = {
 311 -       .name = "minstrel",
 312         .tx_status_ext = minstrel_tx_status,
 313         .get_rate = minstrel_get_rate,
 314         .rate_init = minstrel_rate_init,
 315 -       .alloc = minstrel_alloc,
 316 -       .free = minstrel_free,
 317 -       .alloc_sta = minstrel_alloc_sta,
 318 -       .free_sta = minstrel_free_sta,
 319 -#ifdef CPTCFG_MAC80211_DEBUGFS
 320 -       .add_sta_debugfs = minstrel_add_sta_debugfs,
 321 -#endif
 322         .get_expected_throughput = minstrel_get_expected_throughput,
 323  };
 324 -
 325 -int __init
 326 -rc80211_minstrel_init(void)
 327 -{
 328 -       return ieee80211_rate_control_register(&mac80211_minstrel);
 329 -}
 330 -
 331 -void
 332 -rc80211_minstrel_exit(void)
 333 -{
 334 -       ieee80211_rate_control_unregister(&mac80211_minstrel);
 335 -}
 336 -
 337 --- a/net/mac80211/rc80211_minstrel.h
 338 +++ b/net/mac80211/rc80211_minstrel.h
 339 @@ -158,7 +158,5 @@ int minstrel_get_tp_avg(struct minstrel_
 340  /* debugfs */
 341  int minstrel_stats_open(struct inode *inode, struct file *file);
 342  int minstrel_stats_csv_open(struct inode *inode, struct file *file);
 343 -ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
 344 -int minstrel_stats_release(struct inode *inode, struct file *file);
 345
 346  #endif
 347 --- a/net/mac80211/rc80211_minstrel_debugfs.c
 348 +++ b/net/mac80211/rc80211_minstrel_debugfs.c
 349 @@ -54,22 +54,6 @@
 350  #include <net/mac80211.h>
 351  #include "rc80211_minstrel.h"
 352
 353 -ssize_t
 354 -minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos)
 355 -{
 356 -       struct minstrel_debugfs_info *ms;
 357 -
 358 -       ms = file->private_data;
 359 -       return simple_read_from_buffer(buf, len, ppos, ms->buf, ms->len);
 360 -}
 361 -
 362 -int
 363 -minstrel_stats_release(struct inode *inode, struct file *file)
 364 -{
 365 -       kfree(file->private_data);
 366 -       return 0;
 367 -}
 368 -
 369  int
 370  minstrel_stats_open(struct inode *inode, struct file *file)
 371  {
 372 @@ -135,14 +119,6 @@ minstrel_stats_open(struct inode *inode,
 373         return 0;
 374  }
 375
 376 -static const struct file_operations minstrel_stat_fops = {
 377 -       .owner = THIS_MODULE,
 378 -       .open = minstrel_stats_open,
 379 -       .read = minstrel_stats_read,
 380 -       .release = minstrel_stats_release,
 381 -       .llseek = default_llseek,
 382 -};
 383 -
 384  int
 385  minstrel_stats_csv_open(struct inode *inode, struct file *file)
 386  {
 387 @@ -200,21 +176,3 @@ minstrel_stats_csv_open(struct inode *in
 388
 389         return 0;
 390  }
 391 -
 392 -static const struct file_operations minstrel_stat_csv_fops = {
 393 -       .owner = THIS_MODULE,
 394 -       .open = minstrel_stats_csv_open,
 395 -       .read = minstrel_stats_read,
 396 -       .release = minstrel_stats_release,
 397 -       .llseek = default_llseek,
 398 -};
 399 -
 400 -void
 401 -minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
 402 -{
 403 -       struct minstrel_sta_info *mi = priv_sta;
 404 -
 405 -       debugfs_create_file("rc_stats", S_IRUGO, dir, mi, &minstrel_stat_fops);
 406 -       debugfs_create_file("rc_stats_csv", S_IRUGO, dir, mi,
 407 -                           &minstrel_stat_csv_fops);
 408 -}
 409 --- a/net/mac80211/rc80211_minstrel_ht.c
 410 +++ b/net/mac80211/rc80211_minstrel_ht.c
 411 @@ -137,12 +137,10 @@
 412                 }                                       \
 413         }
 414
 415 -#ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT
 416  static bool minstrel_vht_only = true;
 417  module_param(minstrel_vht_only, bool, 0644);
 418  MODULE_PARM_DESC(minstrel_vht_only,
 419                  "Use only VHT rates when VHT is supported by sta.");
 420 -#endif
 421
 422  /*
 423   * To enable sufficiently targeted rate sampling, MCS rates are divided into
 424 @@ -171,7 +169,6 @@ const struct mcs_group minstrel_mcs_grou
 425
 426         CCK_GROUP,
 427
 428 -#ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT
 429         VHT_GROUP(1, 0, BW_20),
 430         VHT_GROUP(2, 0, BW_20),
 431         VHT_GROUP(3, 0, BW_20),
 432 @@ -195,7 +192,6 @@ const struct mcs_group minstrel_mcs_grou
 433         VHT_GROUP(1, 1, BW_80),
 434         VHT_GROUP(2, 1, BW_80),
 435         VHT_GROUP(3, 1, BW_80),
 436 -#endif
 437  };
 438
 439  static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
 440 @@ -1146,12 +1142,10 @@ minstrel_ht_update_caps(void *priv, stru
 441
 442         BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
 443
 444 -#ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT
 445         if (vht_cap->vht_supported)
 446                 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
 447         else
 448 -#endif
 449 -       use_vht = 0;
 450 +               use_vht = 0;
 451
 452         msp->is_ht = true;
 453         memset(mi, 0, sizeof(*mi));
 454 @@ -1226,10 +1220,9 @@ minstrel_ht_update_caps(void *priv, stru
 455
 456                 /* HT rate */
 457                 if (gflags & IEEE80211_TX_RC_MCS) {
 458 -#ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT
 459                         if (use_vht && minstrel_vht_only)
 460                                 continue;
 461 -#endif
 462 +
 463                         mi->supported[i] = mcs->rx_mask[nss - 1];
 464                         if (mi->supported[i])
 465                                 n_supported++;
 466 @@ -1352,13 +1345,52 @@ minstrel_ht_free_sta(void *priv, struct
 467  static void *
 468  minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 469  {
 470 -       return mac80211_minstrel.alloc(hw, debugfsdir);
 471 +       struct minstrel_priv *mp;
 472 +
 473 +       mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
 474 +       if (!mp)
 475 +               return NULL;
 476 +
 477 +       /* contention window settings
 478 +        * Just an approximation. Using the per-queue values would complicate
 479 +        * the calculations and is probably unnecessary */
 480 +       mp->cw_min = 15;
 481 +       mp->cw_max = 1023;
 482 +
 483 +       /* number of packets (in %) to use for sampling other rates
 484 +        * sample less often for non-mrr packets, because the overhead
 485 +        * is much higher than with mrr */
 486 +       mp->lookaround_rate = 5;
 487 +       mp->lookaround_rate_mrr = 10;
 488 +
 489 +       /* maximum time that the hw is allowed to stay in one MRR segment */
 490 +       mp->segment_size = 6000;
 491 +
 492 +       if (hw->max_rate_tries > 0)
 493 +               mp->max_retry = hw->max_rate_tries;
 494 +       else
 495 +               /* safe default, does not necessarily have to match hw properties */
 496 +               mp->max_retry = 7;
 497 +
 498 +       if (hw->max_rates >= 4)
 499 +               mp->has_mrr = true;
 500 +
 501 +       mp->hw = hw;
 502 +       mp->update_interval = 100;
 503 +
 504 +#ifdef CPTCFG_MAC80211_DEBUGFS
 505 +       mp->fixed_rate_idx = (u32) -1;
 506 +       debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
 507 +                          &mp->fixed_rate_idx);
 508 +#endif
 509 +
 510 +       return mp;
 511  }
 512
 513  static void
 514  minstrel_ht_free(void *priv)
 515  {
 516 -       mac80211_minstrel.free(priv);
 517 +       kfree(priv);
 518  }
 519
 520  static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
 521 @@ -1417,14 +1449,14 @@ static void __init init_sample_table(voi
 522  }
 523
 524  int __init
 525 -rc80211_minstrel_ht_init(void)
 526 +rc80211_minstrel_init(void)
 527  {
 528         init_sample_table();
 529         return ieee80211_rate_control_register(&mac80211_minstrel_ht);
 530  }
 531
 532  void
 533 -rc80211_minstrel_ht_exit(void)
 534 +rc80211_minstrel_exit(void)
 535  {
 536         ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
 537  }
 538 --- a/net/mac80211/rc80211_minstrel_ht.h
 539 +++ b/net/mac80211/rc80211_minstrel_ht.h
 540 @@ -15,11 +15,7 @@
 541   */
 542  #define MINSTREL_MAX_STREAMS           3
 543  #define MINSTREL_HT_STREAM_GROUPS      4 /* BW(=2) * SGI(=2) */
 544 -#ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT
 545  #define MINSTREL_VHT_STREAM_GROUPS     6 /* BW(=3) * SGI(=2) */
 546 -#else
 547 -#define MINSTREL_VHT_STREAM_GROUPS     0
 548 -#endif
 549
 550  #define MINSTREL_HT_GROUPS_NB  (MINSTREL_MAX_STREAMS *         \
 551                                  MINSTREL_HT_STREAM_GROUPS)
 552 @@ -34,11 +30,7 @@
 553  #define MINSTREL_CCK_GROUP     (MINSTREL_HT_GROUP_0 + MINSTREL_HT_GROUPS_NB)
 554  #define MINSTREL_VHT_GROUP_0   (MINSTREL_CCK_GROUP + 1)
 555
 556 -#ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT
 557  #define MCS_GROUP_RATES                10
 558 -#else
 559 -#define MCS_GROUP_RATES                8
 560 -#endif
 561
 562  struct mcs_group {
 563         u32 flags;
 564 --- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
 565 +++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
 566 @@ -15,6 +15,22 @@
 567  #include "rc80211_minstrel.h"
 568  #include "rc80211_minstrel_ht.h"
 569
 570 +static ssize_t
 571 +minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos)
 572 +{
 573 +       struct minstrel_debugfs_info *ms;
 574 +
 575 +       ms = file->private_data;
 576 +       return simple_read_from_buffer(buf, len, ppos, ms->buf, ms->len);
 577 +}
 578 +
 579 +static int
 580 +minstrel_stats_release(struct inode *inode, struct file *file)
 581 +{
 582 +       kfree(file->private_data);
 583 +       return 0;
 584 +}
 585 +
 586  static char *
 587  minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 588  {