[rt2x00-users] [RFT] rt2x00: Tear down BA session on QoS frame failure

[Helmut Schaa]

rt2800 hardware is not able to correctly report the tx status of BAR
frames. Hence, instead of letting mac80211 send a BAR when an AMPDU
subframe fails to flush the peers RX reorder buffer we just take down
the whole BA session.

This mimics the bahavior of the ralink legacy drivers.

Signed-off-by: Helmut Schaa <helmut.schaa at googlemail.com>
---

Tested on a single processor system and seems to work just fine.
Andreas, mind to run some tests with your rt2800pci AP as well?

Thanks,
Helmut

 drivers/net/wireless/rt2x00/rt2x00dev.c |   22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 49a51b4..b57094a 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -280,7 +280,8 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 	u8 rate_idx, rate_flags, retry_rates;
 	u8 skbdesc_flags = skbdesc->flags;
 	bool success;
-
+	struct ieee80211_sta *sta;
+       
 	/*
 	 * Unmap the skb.
 	 */
@@ -340,6 +341,8 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 	retry_rates = test_bit(TXDONE_FALLBACK, &txdesc->flags) ?
 	    (txdesc->retry + 1) : 1;
 
+	sta = tx_info->control.sta;
+
 	/*
 	 * Initialize TX status
 	 */
@@ -392,8 +395,21 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 		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 an AMPDU failed, tear down the BA session
+		 * instead of letting mac80211 send a BAR.
+		 */
+		struct ieee80211_hdr *hdr = (void *) skb->data;
+		if (sta && !success &&
+		    ieee80211_is_data_qos(hdr->frame_control)) {
+			/*
+			 * Tear down BA session 
+			 */
+			u8 *qc = ieee80211_get_qos_ctl(hdr);
+			int tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
+
+			ieee80211_stop_tx_ba_session(sta, tid);
+		}
 	}
 
 	if (rate_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
-- 
1.7.7