package/kernel/mac80211/patches/subsys/371-mac80211-don-t-apply-flow-control-on-management-fram.patch

   1 From: Johannes Berg <johannes.berg@intel.com>
   2 Date: Fri, 19 Mar 2021 23:28:01 +0100
   3 Subject: [PATCH] mac80211: don't apply flow control on management frames
   4
   5 In some cases (depending on the driver, but it's true e.g. for
   6 iwlwifi) we're using an internal TXQ for management packets,
   7 mostly to simplify the code and to have a place to queue them.
   8 However, it appears that in certain cases we can confuse the
   9 code and management frames are dropped, which is certainly not
  10 what we want.
  11
  12 Short-circuit the processing of management frames. To keep the
  13 impact minimal, only put them on the frags queue and check the
  14 tid == management only for doing that and to skip the airtime
  15 fairness checks, if applicable.
  16
  17 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  18 ---
  19
  20 --- a/net/mac80211/tx.c
  21 +++ b/net/mac80211/tx.c
  22 @@ -5,7 +5,7 @@
  23   * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
  24   * Copyright 2007      Johannes Berg <johannes@sipsolutions.net>
  25   * Copyright 2013-2014  Intel Mobile Communications GmbH
  26 - * Copyright (C) 2018-2020 Intel Corporation
  27 + * Copyright (C) 2018-2021 Intel Corporation
  28   *
  29   * Transmit and frame generation functions.
  30   */
  31 @@ -1388,8 +1388,17 @@ static void ieee80211_txq_enqueue(struct
  32         ieee80211_set_skb_enqueue_time(skb);
  33
  34         spin_lock_bh(&fq->lock);
  35 -       fq_tin_enqueue(fq, tin, flow_idx, skb,
  36 -                      fq_skb_free_func);
  37 +       /*
  38 +        * For management frames, don't really apply codel etc.,
  39 +        * we don't want to apply any shaping or anything we just
  40 +        * want to simplify the driver API by having them on the
  41 +        * txqi.
  42 +        */
  43 +       if (unlikely(txqi->txq.tid == IEEE80211_NUM_TIDS))
  44 +               __skb_queue_tail(&txqi->frags, skb);
  45 +       else
  46 +               fq_tin_enqueue(fq, tin, flow_idx, skb,
  47 +                              fq_skb_free_func);
  48         spin_unlock_bh(&fq->lock);
  49  }
  50
  51 @@ -3815,6 +3824,9 @@ bool ieee80211_txq_airtime_check(struct
  52         if (!txq->sta)
  53                 return true;
  54
  55 +       if (unlikely(txq->tid == IEEE80211_NUM_TIDS))
  56 +               return true;
  57 +
  58         sta = container_of(txq->sta, struct sta_info, sta);
  59         if (atomic_read(&sta->airtime[txq->ac].aql_tx_pending) <
  60             sta->airtime[txq->ac].aql_limit_low)