package/kernel/mac80211/patches/subsys/380-mac80211-fix-reordering-of-buffered-broadcast-packet.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Wed, 28 Nov 2018 22:36:06 +0100
   3 Subject: [PATCH] mac80211: fix reordering of buffered broadcast packets
   4
   5 If the buffered broadcast queue contains packets, letting new packets bypass
   6 that queue can lead to heavy reordering, since the driver is probably throttling
   7 transmission of buffered multicast packets after beacons.
   8
   9 Keep buffering packets until the buffer has been cleared (and no client
  10 is in powersave mode).
  11
  12 Cc: stable@vger.kernel.org
  13 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  14 ---
  15
  16 --- a/net/mac80211/tx.c
  17 +++ b/net/mac80211/tx.c
  18 @@ -439,8 +439,8 @@ ieee80211_tx_h_multicast_ps_buf(struct i
  19         if (ieee80211_hw_check(&tx->local->hw, QUEUE_CONTROL))
  20                 info->hw_queue = tx->sdata->vif.cab_queue;
  21
  22 -       /* no stations in PS mode */
  23 -       if (!atomic_read(&ps->num_sta_ps))
  24 +       /* no stations in PS mode and no buffered packets */
  25 +       if (!atomic_read(&ps->num_sta_ps) && skb_queue_empty(&ps->bc_buf))
  26                 return TX_CONTINUE;
  27
  28         info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;