package/kernel/mac80211/patches/301-ath9k-limit-retries-for-powersave-response-frames.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Thu, 2 Jul 2015 15:20:56 +0200
   3 Subject: [PATCH] ath9k: limit retries for powersave response frames
   4
   5 In some cases, the channel might be busy enough that an ath9k AP's
   6 response to PS-Poll frames might be too slow and the station has already
   7 gone to sleep. To avoid wasting too much airtime on this, limit the
   8 number of retries on such frames and ensure that no sample rate gets
   9 used.
  10
  11 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  12 ---
  13
  14 --- a/drivers/net/wireless/ath/ath9k/xmit.c
  15 +++ b/drivers/net/wireless/ath/ath9k/xmit.c
  16 @@ -136,10 +136,25 @@ static void ath_send_bar(struct ath_atx_
  17  }
  18
  19  static void ath_set_rates(struct ieee80211_vif *vif, struct ieee80211_sta *sta,
  20 -                         struct ath_buf *bf)
  21 +                         struct ath_buf *bf, bool ps)
  22  {
  23 +       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(bf->bf_mpdu);
  24 +
  25 +       if (ps) {
  26 +               /* Clear the first rate to avoid using a sample rate for PS frames */
  27 +               info->control.rates[0].idx = -1;
  28 +               info->control.rates[0].count = 0;
  29 +       }
  30 +
  31         ieee80211_get_tx_rates(vif, sta, bf->bf_mpdu, bf->rates,
  32                                ARRAY_SIZE(bf->rates));
  33 +       if (!ps)
  34 +               return;
  35 +
  36 +       if (bf->rates[0].count > 2)
  37 +               bf->rates[0].count = 2;
  38 +
  39 +       bf->rates[1].idx = -1;
  40  }
  41
  42  static void ath_txq_skb_done(struct ath_softc *sc, struct ath_txq *txq,
  43 @@ -1419,7 +1434,7 @@ ath_tx_form_burst(struct ath_softc *sc,
  44                 if (tx_info->flags & IEEE80211_TX_CTL_AMPDU)
  45                         break;
  46
  47 -               ath_set_rates(tid->an->vif, tid->an->sta, bf);
  48 +               ath_set_rates(tid->an->vif, tid->an->sta, bf, false);
  49         } while (1);
  50  }
  51
  52 @@ -1450,7 +1465,7 @@ static bool ath_tx_sched_aggr(struct ath
  53                 return false;
  54         }
  55
  56 -       ath_set_rates(tid->an->vif, tid->an->sta, bf);
  57 +       ath_set_rates(tid->an->vif, tid->an->sta, bf, false);
  58         if (aggr)
  59                 last = ath_tx_form_aggr(sc, txq, tid, &bf_q, bf,
  60                                         tid_q, &aggr_len);
  61 @@ -1647,7 +1662,7 @@ void ath9k_release_buffered_frames(struc
  62
  63                         __skb_unlink(bf->bf_mpdu, tid_q);
  64                         list_add_tail(&bf->list, &bf_q);
  65 -                       ath_set_rates(tid->an->vif, tid->an->sta, bf);
  66 +                       ath_set_rates(tid->an->vif, tid->an->sta, bf, true);
  67                         if (bf_isampdu(bf)) {
  68                                 ath_tx_addto_baw(sc, tid, bf);
  69                                 bf->bf_state.bf_type &= ~BUF_AGGR;
  70 @@ -2293,7 +2308,7 @@ int ath_tx_start(struct ieee80211_hw *hw
  71         struct ath_txq *txq = txctl->txq;
  72         struct ath_atx_tid *tid = NULL;
  73         struct ath_buf *bf;
  74 -       bool queue, skip_uapsd = false, ps_resp;
  75 +       bool queue, ps_resp;
  76         int q, ret;
  77
  78         if (vif)
  79 @@ -2346,13 +2361,13 @@ int ath_tx_start(struct ieee80211_hw *hw
  80                 if (!txctl->an)
  81                         txctl->an = &avp->mcast_node;
  82                 queue = true;
  83 -               skip_uapsd = true;
  84 +               ps_resp = false;
  85         }
  86
  87         if (txctl->an && queue)
  88                 tid = ath_get_skb_tid(sc, txctl->an, skb);
  89
  90 -       if (!skip_uapsd && ps_resp) {
  91 +       if (ps_resp) {
  92                 ath_txq_unlock(sc, txq);
  93                 txq = sc->tx.uapsdq;
  94                 ath_txq_lock(sc, txq);
  95 @@ -2390,7 +2405,7 @@ int ath_tx_start(struct ieee80211_hw *hw
  96         if (txctl->paprd)
  97                 bf->bf_state.bfs_paprd_timestamp = jiffies;
  98
  99 -       ath_set_rates(vif, sta, bf);
 100 +       ath_set_rates(vif, sta, bf, ps_resp);
 101         ath_tx_send_normal(sc, txq, tid, skb);
 102
 103  out:
 104 @@ -2429,7 +2444,7 @@ void ath_tx_cabq(struct ieee80211_hw *hw
 105                         break;
 106
 107                 bf->bf_lastbf = bf;
 108 -               ath_set_rates(vif, NULL, bf);
 109 +               ath_set_rates(vif, NULL, bf, false);
 110                 ath_buf_set_rate(sc, bf, &info, fi->framelen, false);
 111                 duration += info.rates[0].PktDuration;
 112                 if (bf_tail)
 113 @@ -2932,7 +2947,7 @@ int ath9k_tx99_send(struct ath_softc *sc
 114                 return -EINVAL;
 115         }
 116
 117 -       ath_set_rates(sc->tx99_vif, NULL, bf);
 118 +       ath_set_rates(sc->tx99_vif, NULL, bf, false);
 119
 120         ath9k_hw_set_desc_link(sc->sc_ah, bf->bf_desc, bf->bf_daddr);
 121         ath9k_hw_tx99_start(sc->sc_ah, txctl->txq->axq_qnum);