[PATCH 4.16 41/47] Revert "rt2800: use TXOP_BACKOFF for probe frames"

From: Greg Kroah-Hartman
Date: Mon Jun 04 2018 - 03:07:26 EST


4.16-stable review patch. If anyone has any objections, please let me know.

------------------

From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>

commit 52a192362932f333a7ebafd581c4d9b81da2fec8 upstream.

This reverts commit fb47ada8dc3c30c8e7b415da155742b49536c61e.

In some situations when we set TXOP_BACKOFF, the probe frame is
not sent at all. What it worse then sending probe frame as part
of AMPDU and can degrade 11n performance to 11g rates.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/ralink/rt2x00/rt2x00queue.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/ralink/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2x00queue.c
@@ -372,16 +372,15 @@ static void rt2x00queue_create_tx_descri

/*
* Determine IFS values
- * - Use TXOP_BACKOFF for probe and management frames except beacons
+ * - Use TXOP_BACKOFF for management frames except beacons
* - Use TXOP_SIFS for fragment bursts
* - Use TXOP_HTTXOP for everything else
*
* Note: rt2800 devices won't use CTS protection (if used)
* for frames not transmitted with TXOP_HTTXOP
*/
- if ((ieee80211_is_mgmt(hdr->frame_control) &&
- !ieee80211_is_beacon(hdr->frame_control)) ||
- (tx_info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE))
+ if (ieee80211_is_mgmt(hdr->frame_control) &&
+ !ieee80211_is_beacon(hdr->frame_control))
txdesc->u.ht.txop = TXOP_BACKOFF;
else if (!(tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT))
txdesc->u.ht.txop = TXOP_SIFS;