package/kernel/mac80211/patches/300-mac80211-add-an-intermediate-software-queue-implemen.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2 Date: Tue, 18 Nov 2014 23:58:51 +0100
   3 Subject: [PATCH] mac80211: add an intermediate software queue implementation
   4
   5 This allows drivers to request per-vif and per-sta-tid queues from which
   6 they can pull frames. This makes it easier to keep the hardware queues
   7 short, and to improve fairness between clients and vifs.
   8
   9 The task of scheduling packet transmission is left up to the driver -
  10 queueing is controlled by mac80211. Drivers can only dequeue packets by
  11 calling ieee80211_tx_dequeue. This makes it possible to add active queue
  12 management later without changing drivers using this code.
  13
  14 This can also be used as a starting point to implement A-MSDU
  15 aggregation in a way that does not add artificially induced latency.
  16
  17 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
  18 ---
  19
  20 --- a/include/net/mac80211.h
  21 +++ b/include/net/mac80211.h
  22 @@ -1257,6 +1257,8 @@ struct ieee80211_vif {
  23         u8 cab_queue;
  24         u8 hw_queue[IEEE80211_NUM_ACS];
  25
  26 +       struct ieee80211_txq *txq;
  27 +
  28         struct ieee80211_chanctx_conf __rcu *chanctx_conf;
  29
  30         u32 driver_flags;
  31 @@ -1519,6 +1521,8 @@ struct ieee80211_sta {
  32         bool tdls_initiator;
  33         bool mfp;
  34
  35 +       struct ieee80211_txq *txq[IEEE80211_NUM_TIDS];
  36 +
  37         /* must be last */
  38         u8 drv_priv[0] __aligned(sizeof(void *));
  39  };
  40 @@ -1547,6 +1551,27 @@ struct ieee80211_tx_control {
  41  };
  42
  43  /**
  44 + * struct ieee80211_txq - Software intermediate tx queue
  45 + *
  46 + * @vif: &struct ieee80211_vif pointer from the add_interface callback.
  47 + * @sta: station table entry, may be NULL for per-vif queue
  48 + * @tid: the TID for this queue (unset for per-vif queue)
  49 + * @ac: the AC for this queue
  50 + *
  51 + * The driver can obtain packets from this queue by calling
  52 + * ieee80211_tx_dequeue().
  53 + */
  54 +struct ieee80211_txq {
  55 +       struct ieee80211_vif *vif;
  56 +       struct ieee80211_sta *sta;
  57 +       u8 tid;
  58 +       u8 ac;
  59 +
  60 +       /* must be last */
  61 +       u8 drv_priv[0] __aligned(sizeof(void *));
  62 +};
  63 +
  64 +/**
  65   * enum ieee80211_hw_flags - hardware flags
  66   *
  67   * These flags are used to indicate hardware capabilities to
  68 @@ -1770,6 +1795,8 @@ enum ieee80211_hw_flags {
  69   *     within &struct ieee80211_sta.
  70   * @chanctx_data_size: size (in bytes) of the drv_priv data area
  71   *     within &struct ieee80211_chanctx_conf.
  72 + * @txq_data_size: size (in bytes) of the drv_priv data area
  73 + *     within @struct ieee80211_txq.
  74   *
  75   * @max_rates: maximum number of alternate rate retry stages the hw
  76   *     can handle.
  77 @@ -1818,6 +1845,9 @@ enum ieee80211_hw_flags {
  78   * @n_cipher_schemes: a size of an array of cipher schemes definitions.
  79   * @cipher_schemes: a pointer to an array of cipher scheme definitions
  80   *     supported by HW.
  81 + *
  82 + * @txq_ac_max_pending: maximum number of frames per AC pending in all txq
  83 + *     entries for a vif.
  84   */
  85  struct ieee80211_hw {
  86         struct ieee80211_conf conf;
  87 @@ -1830,6 +1860,7 @@ struct ieee80211_hw {
  88         int vif_data_size;
  89         int sta_data_size;
  90         int chanctx_data_size;
  91 +       int txq_data_size;
  92         u16 queues;
  93         u16 max_listen_interval;
  94         s8 max_signal;
  95 @@ -1846,6 +1877,7 @@ struct ieee80211_hw {
  96         u8 uapsd_max_sp_len;
  97         u8 n_cipher_schemes;
  98         const struct ieee80211_cipher_scheme *cipher_schemes;
  99 +       int txq_ac_max_pending;
 100  };
 101
 102  /**
 103 @@ -3007,6 +3039,8 @@ enum ieee80211_reconfig_type {
 104   *     response template is provided, together with the location of the
 105   *     switch-timing IE within the template. The skb can only be used within
 106   *     the function call.
 107 + *
 108 + * @wake_tx_queue: Called when new packets have been added to the queue.
 109   */
 110  struct ieee80211_ops {
 111         void (*tx)(struct ieee80211_hw *hw,
 112 @@ -3238,6 +3272,9 @@ struct ieee80211_ops {
 113         void (*tdls_recv_channel_switch)(struct ieee80211_hw *hw,
 114                                          struct ieee80211_vif *vif,
 115                                          struct ieee80211_tdls_ch_sw_params *params);
 116 +
 117 +       void (*wake_tx_queue)(struct ieee80211_hw *hw,
 118 +                             struct ieee80211_txq *txq);
 119  };
 120
 121  /**
 122 @@ -5249,4 +5286,17 @@ void ieee80211_unreserve_tid(struct ieee
 123   */
 124  size_t ieee80211_ie_split(const u8 *ies, size_t ielen,
 125                           const u8 *ids, int n_ids, size_t offset);
 126 +
 127 +/**
 128 + * ieee80211_tx_dequeue - dequeue a packet from a software tx queue
 129 + *
 130 + * @hw: pointer as obtained from ieee80211_alloc_hw()
 131 + * @txq: pointer obtained from .add_tx_queue() call
 132 + *
 133 + * Returns the sjb if successful, ERR_PTR(-EAGAIN) if no frame was available.
 134 + */
 135 +struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
 136 +                                    struct ieee80211_txq *txq);
 137 +
 138 +
 139  #endif /* MAC80211_H */
 140 --- a/net/mac80211/driver-ops.h
 141 +++ b/net/mac80211/driver-ops.h
 142 @@ -1367,4 +1367,21 @@ drv_tdls_recv_channel_switch(struct ieee
 143         trace_drv_return_void(local);
 144  }
 145
 146 +static inline void drv_wake_tx_queue(struct ieee80211_local *local,
 147 +                                    struct txq_info *txq)
 148 +{
 149 +       struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->txq.vif);
 150 +
 151 +       if (!check_sdata_in_driver(sdata))
 152 +               return;
 153 +
 154 +       if (txq->txq.sta)
 155 +               trace_drv_wake_sta_tx_queue(local, sdata, txq->txq.sta,
 156 +                                           txq->txq.tid);
 157 +       else
 158 +               trace_drv_wake_vif_tx_queue(local, sdata);
 159 +
 160 +       local->ops->wake_tx_queue(&local->hw, &txq->txq);
 161 +}
 162 +
 163  #endif /* __MAC80211_DRIVER_OPS */
 164 --- a/net/mac80211/ieee80211_i.h
 165 +++ b/net/mac80211/ieee80211_i.h
 166 @@ -809,6 +809,13 @@ struct mac80211_qos_map {
 167         struct rcu_head rcu_head;
 168  };
 169
 170 +struct txq_info {
 171 +       struct sk_buff_head queue;
 172 +
 173 +       /* keep last! */
 174 +       struct ieee80211_txq txq;
 175 +};
 176 +
 177  struct ieee80211_sub_if_data {
 178         struct list_head list;
 179
 180 @@ -853,6 +860,7 @@ struct ieee80211_sub_if_data {
 181         bool control_port_no_encrypt;
 182         int encrypt_headroom;
 183
 184 +       atomic_t txqs_len[IEEE80211_NUM_ACS];
 185         struct ieee80211_tx_queue_params tx_conf[IEEE80211_NUM_ACS];
 186         struct mac80211_qos_map __rcu *qos_map;
 187
 188 @@ -1905,6 +1913,12 @@ static inline bool ieee80211_can_run_wor
 189         return true;
 190  }
 191
 192 +void ieee80211_init_tx_queue(struct ieee80211_sub_if_data *sdata,
 193 +                            struct sta_info *sta,
 194 +                            struct txq_info *txq, int tid);
 195 +void ieee80211_flush_tx_queue(struct ieee80211_local *local,
 196 +                             struct ieee80211_txq *txq);
 197 +
 198  void ieee80211_send_auth(struct ieee80211_sub_if_data *sdata,
 199                          u16 transaction, u16 auth_alg, u16 status,
 200                          const u8 *extra, size_t extra_len, const u8 *bssid,
 201 --- a/net/mac80211/iface.c
 202 +++ b/net/mac80211/iface.c
 203 @@ -969,6 +969,9 @@ static void ieee80211_do_stop(struct iee
 204         }
 205         spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 206
 207 +       if (sdata->vif.txq)
 208 +               ieee80211_flush_tx_queue(local, sdata->vif.txq);
 209 +
 210         if (local->open_count == 0)
 211                 ieee80211_clear_tx_pending(local);
 212
 213 @@ -1773,6 +1776,15 @@ int ieee80211_if_add(struct ieee80211_lo
 214         ieee80211_setup_sdata(sdata, type);
 215
 216         if (ndev) {
 217 +               struct txq_info *txqi = NULL;
 218 +
 219 +               if (local->ops->wake_tx_queue) {
 220 +                       txqi = kzalloc(sizeof(*txqi) +
 221 +                                     local->hw.txq_data_size, GFP_KERNEL);
 222 +                       if (txqi)
 223 +                               ieee80211_init_tx_queue(sdata, NULL, txqi, 0);
 224 +               }
 225 +
 226                 if (params) {
 227                         ndev->ieee80211_ptr->use_4addr = params->use_4addr;
 228                         if (type == NL80211_IFTYPE_STATION)
 229 @@ -1785,6 +1797,7 @@ int ieee80211_if_add(struct ieee80211_lo
 230
 231                 ret = register_netdevice(ndev);
 232                 if (ret) {
 233 +                       kfree(txqi);
 234                         free_netdev(ndev);
 235                         return ret;
 236                 }
 237 @@ -1802,6 +1815,7 @@ int ieee80211_if_add(struct ieee80211_lo
 238
 239  void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
 240  {
 241 +       struct txq_info *txqi;
 242         ASSERT_RTNL();
 243
 244         mutex_lock(&sdata->local->iflist_mtx);
 245 @@ -1810,6 +1824,11 @@ void ieee80211_if_remove(struct ieee8021
 246
 247         synchronize_rcu();
 248
 249 +       if (sdata->vif.txq) {
 250 +               txqi = container_of(sdata->vif.txq, struct txq_info, txq);
 251 +               kfree(txqi);
 252 +       }
 253 +
 254         if (sdata->dev) {
 255                 unregister_netdevice(sdata->dev);
 256         } else {
 257 @@ -1833,6 +1852,7 @@ void ieee80211_sdata_stop(struct ieee802
 258  void ieee80211_remove_interfaces(struct ieee80211_local *local)
 259  {
 260         struct ieee80211_sub_if_data *sdata, *tmp;
 261 +       struct txq_info *txqi;
 262         LIST_HEAD(unreg_list);
 263         LIST_HEAD(wdev_list);
 264
 265 @@ -1851,6 +1871,12 @@ void ieee80211_remove_interfaces(struct
 266         list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
 267                 list_del(&sdata->list);
 268
 269 +               if (sdata->vif.txq) {
 270 +                       txqi = container_of(sdata->vif.txq, struct txq_info,
 271 +                                          txq);
 272 +                       kfree(txqi);
 273 +               }
 274 +
 275                 if (sdata->dev)
 276                         unregister_netdevice_queue(sdata->dev, &unreg_list);
 277                 else
 278 --- a/net/mac80211/main.c
 279 +++ b/net/mac80211/main.c
 280 @@ -1019,6 +1019,9 @@ int ieee80211_register_hw(struct ieee802
 281
 282         local->dynamic_ps_forced_timeout = -1;
 283
 284 +       if (!local->hw.txq_ac_max_pending)
 285 +               local->hw.txq_ac_max_pending = 64;
 286 +
 287         result = ieee80211_wep_init(local);
 288         if (result < 0)
 289                 wiphy_debug(local->hw.wiphy, "Failed to initialize wep: %d\n",
 290 --- a/net/mac80211/sta_info.c
 291 +++ b/net/mac80211/sta_info.c
 292 @@ -118,6 +118,11 @@ static void __cleanup_single_sta(struct
 293                 atomic_dec(&ps->num_sta_ps);
 294         }
 295
 296 +       if (sta->txq) {
 297 +               for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 298 +                       ieee80211_flush_tx_queue(local, sta->sta.txq[i]);
 299 +       }
 300 +
 301         for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
 302                 local->total_ps_buffered -= skb_queue_len(&sta->ps_tx_buf[ac]);
 303                 ieee80211_purge_tx_queue(&local->hw, &sta->ps_tx_buf[ac]);
 304 @@ -234,6 +239,7 @@ void sta_info_free(struct ieee80211_loca
 305
 306         sta_dbg(sta->sdata, "Destroyed STA %pM\n", sta->sta.addr);
 307
 308 +       kfree(sta->txq);
 309         kfree(rcu_dereference_raw(sta->sta.rates));
 310         kfree(sta);
 311  }
 312 @@ -285,11 +291,12 @@ struct sta_info *sta_info_alloc(struct i
 313                                 const u8 *addr, gfp_t gfp)
 314  {
 315         struct ieee80211_local *local = sdata->local;
 316 +       struct ieee80211_hw *hw = &local->hw;
 317         struct sta_info *sta;
 318         struct timespec uptime;
 319         int i;
 320
 321 -       sta = kzalloc(sizeof(*sta) + local->hw.sta_data_size, gfp);
 322 +       sta = kzalloc(sizeof(*sta) + hw->sta_data_size, gfp);
 323         if (!sta)
 324                 return NULL;
 325
 326 @@ -321,11 +328,23 @@ struct sta_info *sta_info_alloc(struct i
 327         for (i = 0; i < ARRAY_SIZE(sta->chain_signal_avg); i++)
 328                 ewma_init(&sta->chain_signal_avg[i], 1024, 8);
 329
 330 -       if (sta_prepare_rate_control(local, sta, gfp)) {
 331 -               kfree(sta);
 332 -               return NULL;
 333 +       if (local->ops->wake_tx_queue) {
 334 +               int size = sizeof(struct txq_info) +
 335 +                          ALIGN(hw->txq_data_size, sizeof(void *));
 336 +
 337 +               sta->txq = kcalloc(IEEE80211_NUM_TIDS, size, gfp);
 338 +               if (!sta->txq)
 339 +                       goto free;
 340 +
 341 +               for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 342 +                       struct txq_info *txq = sta->txq + i * size;
 343 +                       ieee80211_init_tx_queue(sdata, sta, txq, i);
 344 +               }
 345         }
 346
 347 +       if (sta_prepare_rate_control(local, sta, gfp))
 348 +               goto free_txq;
 349 +
 350         for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
 351                 /*
 352                  * timer_to_tid must be initialized with identity mapping
 353 @@ -346,7 +365,7 @@ struct sta_info *sta_info_alloc(struct i
 354         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 355             sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 356                 struct ieee80211_supported_band *sband =
 357 -                       local->hw.wiphy->bands[ieee80211_get_sdata_band(sdata)];
 358 +                       hw->wiphy->bands[ieee80211_get_sdata_band(sdata)];
 359                 u8 smps = (sband->ht_cap.cap & IEEE80211_HT_CAP_SM_PS) >>
 360                                 IEEE80211_HT_CAP_SM_PS_SHIFT;
 361                 /*
 362 @@ -371,6 +390,12 @@ struct sta_info *sta_info_alloc(struct i
 363         sta_dbg(sdata, "Allocated STA %pM\n", sta->sta.addr);
 364
 365         return sta;
 366 +
 367 +free_txq:
 368 +       kfree(sta->txq);
 369 +free:
 370 +       kfree(sta);
 371 +       return NULL;
 372  }
 373
 374  static int sta_info_insert_check(struct sta_info *sta)
 375 --- a/net/mac80211/sta_info.h
 376 +++ b/net/mac80211/sta_info.h
 377 @@ -368,6 +368,7 @@ struct sta_info {
 378         struct sk_buff_head ps_tx_buf[IEEE80211_NUM_ACS];
 379         struct sk_buff_head tx_filtered[IEEE80211_NUM_ACS];
 380         unsigned long driver_buffered_tids;
 381 +       struct txq_info *txq;
 382
 383         /* Updated from RX path only, no locking requirements */
 384         unsigned long rx_packets;
 385 --- a/net/mac80211/trace.h
 386 +++ b/net/mac80211/trace.h
 387 @@ -2312,6 +2312,40 @@ TRACE_EVENT(drv_tdls_recv_channel_switch
 388         )
 389  );
 390
 391 +DEFINE_EVENT(local_sdata_evt, drv_wake_vif_tx_queue,
 392 +       TP_PROTO(struct ieee80211_local *local,
 393 +                struct ieee80211_sub_if_data *sdata),
 394 +       TP_ARGS(local, sdata)
 395 +);
 396 +
 397 +TRACE_EVENT(drv_wake_sta_tx_queue,
 398 +       TP_PROTO(struct ieee80211_local *local,
 399 +                struct ieee80211_sub_if_data *sdata,
 400 +                struct ieee80211_sta *sta,
 401 +                u8 tid),
 402 +
 403 +       TP_ARGS(local, sdata, sta, tid),
 404 +
 405 +       TP_STRUCT__entry(
 406 +               LOCAL_ENTRY
 407 +               VIF_ENTRY
 408 +               STA_ENTRY
 409 +               __field(u8, tid)
 410 +       ),
 411 +
 412 +       TP_fast_assign(
 413 +               LOCAL_ASSIGN;
 414 +               VIF_ASSIGN;
 415 +               STA_ASSIGN;
 416 +               __entry->tid = tid;
 417 +       ),
 418 +
 419 +       TP_printk(
 420 +               LOCAL_PR_FMT  VIF_PR_FMT  STA_PR_FMT " tid: 0x%x",
 421 +               LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->tid
 422 +       )
 423 +);
 424 +
 425  #ifdef CPTCFG_MAC80211_MESSAGE_TRACING
 426  #undef TRACE_SYSTEM
 427  #define TRACE_SYSTEM mac80211_msg
 428 --- a/net/mac80211/tx.c
 429 +++ b/net/mac80211/tx.c
 430 @@ -1201,13 +1201,76 @@ ieee80211_tx_prepare(struct ieee80211_su
 431         return TX_CONTINUE;
 432  }
 433
 434 +static void ieee80211_drv_tx(struct ieee80211_local *local,
 435 +                            struct ieee80211_vif *vif,
 436 +                            struct ieee80211_sta *pubsta,
 437 +                            struct sk_buff *skb)
 438 +{
 439 +       struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 440 +       struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 441 +       struct ieee80211_tx_control control = {
 442 +               .sta = pubsta
 443 +       };
 444 +       struct ieee80211_txq *txq = NULL;
 445 +       struct txq_info *txqi;
 446 +       u8 ac;
 447 +
 448 +       if (ieee80211_is_mgmt(hdr->frame_control) ||
 449 +           ieee80211_is_ctl(hdr->frame_control))
 450 +               goto tx_normal;
 451 +
 452 +       if (pubsta) {
 453 +               u8 tid = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
 454 +               txq = pubsta->txq[tid];
 455 +       } else if (vif) {
 456 +               txq = vif->txq;
 457 +       }
 458 +
 459 +       if (!txq)
 460 +               goto tx_normal;
 461 +
 462 +       ac = txq->ac;
 463 +       txqi = container_of(txq, struct txq_info, txq);
 464 +       atomic_inc(&sdata->txqs_len[ac]);
 465 +       if (atomic_read(&sdata->txqs_len[ac]) >= local->hw.txq_ac_max_pending)
 466 +               netif_stop_subqueue(sdata->dev, ac);
 467 +
 468 +       skb_queue_tail(&txqi->queue, skb);
 469 +       drv_wake_tx_queue(local, txqi);
 470 +
 471 +       return;
 472 +
 473 +tx_normal:
 474 +       drv_tx(local, &control, skb);
 475 +}
 476 +
 477 +struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
 478 +                                    struct ieee80211_txq *txq)
 479 +{
 480 +       struct ieee80211_local *local = hw_to_local(hw);
 481 +       struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->vif);
 482 +       struct txq_info *txqi = container_of(txq, struct txq_info, txq);
 483 +       struct sk_buff *skb;
 484 +       u8 ac = txq->ac;
 485 +
 486 +       skb = skb_dequeue(&txqi->queue);
 487 +       if (!skb)
 488 +               return ERR_PTR(-EAGAIN);
 489 +
 490 +       atomic_dec(&sdata->txqs_len[ac]);
 491 +       if (__netif_subqueue_stopped(sdata->dev, ac))
 492 +               ieee80211_propagate_queue_wake(local, sdata->vif.hw_queue[ac]);
 493 +
 494 +       return skb;
 495 +}
 496 +EXPORT_SYMBOL(ieee80211_tx_dequeue);
 497 +
 498  static bool ieee80211_tx_frags(struct ieee80211_local *local,
 499                                struct ieee80211_vif *vif,
 500                                struct ieee80211_sta *sta,
 501                                struct sk_buff_head *skbs,
 502                                bool txpending)
 503  {
 504 -       struct ieee80211_tx_control control;
 505         struct sk_buff *skb, *tmp;
 506         unsigned long flags;
 507
 508 @@ -1265,10 +1328,9 @@ static bool ieee80211_tx_frags(struct ie
 509                 spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 510
 511                 info->control.vif = vif;
 512 -               control.sta = sta;
 513
 514                 __skb_unlink(skb, skbs);
 515 -               drv_tx(local, &control, skb);
 516 +               ieee80211_drv_tx(local, vif, sta, skb);
 517         }
 518
 519         return true;
 520 --- a/net/mac80211/util.c
 521 +++ b/net/mac80211/util.c
 522 @@ -308,6 +308,11 @@ void ieee80211_propagate_queue_wake(stru
 523                 for (ac = 0; ac < n_acs; ac++) {
 524                         int ac_queue = sdata->vif.hw_queue[ac];
 525
 526 +                       if (local->ops->wake_tx_queue &&
 527 +                           (atomic_read(&sdata->txqs_len[ac]) >
 528 +                            local->hw.txq_ac_max_pending))
 529 +                               continue;
 530 +
 531                         if (ac_queue == queue ||
 532                             (sdata->vif.cab_queue == queue &&
 533                              local->queue_stop_reasons[ac_queue] == 0 &&
 534 @@ -3307,3 +3312,36 @@ u8 *ieee80211_add_wmm_info_ie(u8 *buf, u
 535
 536         return buf;
 537  }
 538 +
 539 +void ieee80211_init_tx_queue(struct ieee80211_sub_if_data *sdata,
 540 +                            struct sta_info *sta,
 541 +                            struct txq_info *txqi, int tid)
 542 +{
 543 +       skb_queue_head_init(&txqi->queue);
 544 +       txqi->txq.vif = &sdata->vif;
 545 +
 546 +       if (sta) {
 547 +               txqi->txq.sta = &sta->sta;
 548 +               sta->sta.txq[tid] = &txqi->txq;
 549 +               txqi->txq.ac = ieee802_1d_to_ac[tid & 7];
 550 +       } else {
 551 +               sdata->vif.txq = &txqi->txq;
 552 +               txqi->txq.ac = IEEE80211_AC_BE;
 553 +       }
 554 +}
 555 +
 556 +void ieee80211_flush_tx_queue(struct ieee80211_local *local,
 557 +                             struct ieee80211_txq *txq)
 558 +{
 559 +       struct txq_info *txqi = container_of(txq, struct txq_info, txq);
 560 +       struct ieee80211_sub_if_data *sdata = vif_to_sdata(txq->vif);
 561 +       struct sk_buff *skb;
 562 +       int n = 0;
 563 +
 564 +       while ((skb = skb_dequeue(&txqi->queue)) != NULL) {
 565 +               n++;
 566 +               ieee80211_free_txskb(&local->hw, skb);
 567 +       }
 568 +
 569 +       atomic_sub(n, &sdata->txqs_len[txq->ac]);
 570 +}