package/kernel/mac80211/patches/rt2x00/015-rt2x00-do-not-set-IEEE80211_TX_STAT_AMPDU_NO_BACK-on-tx-status.patch

   1 From patchwork Fri Aug 23 07:09:56 2019
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   5 X-Patchwork-Submitter: Stanislaw Gruszka <sgruszka@redhat.com>
   6 X-Patchwork-Id: 11110703
   7 X-Patchwork-Delegate: kvalo@adurom.com
   8 From: Stanislaw Gruszka <sgruszka@redhat.com>
   9 To: linux-wireless@vger.kernel.org
  10 Subject: [PATCH] rt2x00: do not set IEEE80211_TX_STAT_AMPDU_NO_BACK on tx
  11  status
  12 Date: Fri, 23 Aug 2019 09:09:56 +0200
  13 Message-Id: <1566544196-20371-1-git-send-email-sgruszka@redhat.com>
  14 Sender: linux-wireless-owner@vger.kernel.org
  15 List-ID: <linux-wireless.vger.kernel.org>
  16 X-Mailing-List: linux-wireless@vger.kernel.org
  17
  18 According to documentation IEEE80211_TX_STAT_AMPDU_NO_BACK is suppose
  19 to be used when we do not recive BA (BlockAck). However on rt2x00 we
  20 use it when remote station fail to decode one or more subframes within
  21 AMPDU (some bits are not set in BlockAck bitmap). Setting the flag result
  22 in sent of BAR (BlockAck Request) frame and this might result of abuse
  23 of BA session, since remote station can sent BA with incorrect
  24 sequence numbers after receiving BAR. This problem is visible especially
  25 when connecting two rt2800 devices.
  26
  27 Previously I observed some performance benefits when using the flag
  28 when connecting with iwlwifi devices. But currently possibly due
  29 to reacent changes in rt2x00 removing the flag has no effect on
  30 those test cases.
  31
  32 So remove the IEEE80211_TX_STAT_AMPDU_NO_BACK.
  33
  34 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
  35 ---
  36  drivers/net/wireless/ralink/rt2x00/rt2x00dev.c | 3 ---
  37  1 file changed, 3 deletions(-)
  38
  39 --- a/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
  40 +++ b/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
  41 @@ -371,9 +371,6 @@ static void rt2x00lib_fill_tx_status(str
  42                                   IEEE80211_TX_CTL_AMPDU;
  43                 tx_info->status.ampdu_len = 1;
  44                 tx_info->status.ampdu_ack_len = success ? 1 : 0;
  45 -
  46 -               if (!success)
  47 -                       tx_info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
  48         }
  49
  50         if (rate_flags & IEEE80211_TX_RC_USE_RTS_CTS) {