* [PATCH] rt2x00: do not set IEEE80211_TX_STAT_AMPDU_NO_BACK on tx status
@ 2019-08-23 7:09 Stanislaw Gruszka
2019-09-03 13:41 ` Kalle Valo
0 siblings, 1 reply; 2+ messages in thread
From: Stanislaw Gruszka @ 2019-08-23 7:09 UTC (permalink / raw)
To: linux-wireless
Cc: Felix Fietkau, Daniel Golle, Tomislav Požega, Mathias Kresin
According to documentation IEEE80211_TX_STAT_AMPDU_NO_BACK is suppose
to be used when we do not recive BA (BlockAck). However on rt2x00 we
use it when remote station fail to decode one or more subframes within
AMPDU (some bits are not set in BlockAck bitmap). Setting the flag result
in sent of BAR (BlockAck Request) frame and this might result of abuse
of BA session, since remote station can sent BA with incorrect
sequence numbers after receiving BAR. This problem is visible especially
when connecting two rt2800 devices.
Previously I observed some performance benefits when using the flag
when connecting with iwlwifi devices. But currently possibly due
to reacent changes in rt2x00 removing the flag has no effect on
those test cases.
So remove the IEEE80211_TX_STAT_AMPDU_NO_BACK.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
drivers/net/wireless/ralink/rt2x00/rt2x00dev.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c b/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
index 9d158237ac67..c3eab767bc21 100644
--- a/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
@@ -371,9 +371,6 @@ static void rt2x00lib_fill_tx_status(struct rt2x00_dev *rt2x00dev,
IEEE80211_TX_CTL_AMPDU;
tx_info->status.ampdu_len = 1;
tx_info->status.ampdu_ack_len = success ? 1 : 0;
-
- if (!success)
- tx_info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
}
if (rate_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
--
1.9.3
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] rt2x00: do not set IEEE80211_TX_STAT_AMPDU_NO_BACK on tx status
2019-08-23 7:09 [PATCH] rt2x00: do not set IEEE80211_TX_STAT_AMPDU_NO_BACK on tx status Stanislaw Gruszka
@ 2019-09-03 13:41 ` Kalle Valo
0 siblings, 0 replies; 2+ messages in thread
From: Kalle Valo @ 2019-09-03 13:41 UTC (permalink / raw)
To: Stanislaw Gruszka
Cc: linux-wireless, Felix Fietkau, Daniel Golle,
Tomislav Požega, Mathias Kresin
Stanislaw Gruszka <sgruszka@redhat.com> wrote:
> According to documentation IEEE80211_TX_STAT_AMPDU_NO_BACK is suppose
> to be used when we do not recive BA (BlockAck). However on rt2x00 we
> use it when remote station fail to decode one or more subframes within
> AMPDU (some bits are not set in BlockAck bitmap). Setting the flag result
> in sent of BAR (BlockAck Request) frame and this might result of abuse
> of BA session, since remote station can sent BA with incorrect
> sequence numbers after receiving BAR. This problem is visible especially
> when connecting two rt2800 devices.
>
> Previously I observed some performance benefits when using the flag
> when connecting with iwlwifi devices. But currently possibly due
> to reacent changes in rt2x00 removing the flag has no effect on
> those test cases.
>
> So remove the IEEE80211_TX_STAT_AMPDU_NO_BACK.
>
> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Patch applied to wireless-drivers-next.git, thanks.
567a9b766b47 rt2x00: do not set IEEE80211_TX_STAT_AMPDU_NO_BACK on tx status
--
https://patchwork.kernel.org/patch/11110703/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 2+ messages in thread
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