ath9k: rework handling of sending BlockAckReq frames, should hopefully lead to fewer latency spikes

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@27888 3c298f89-4303-0410-b956-a3cf2f4a3e73

2 files changed, 213 insertions, 0 deletions

diff --git a/package/mac80211/patches/570-mac80211_send_bar.patch b/package/mac80211/patches/570-mac80211_send_bar.patch
new file mode 100644
index 000000000..5952da69c
--- /dev/null
+++ b/package/mac80211/patches/570-mac80211_send_bar.patch
@@ -0,0 +1,64 @@
+--- a/net/mac80211/agg-tx.c
++++ b/net/mac80211/agg-tx.c
+@@ -109,8 +109,9 @@ static void ieee80211_send_addba_request
+ 	ieee80211_tx_skb(sdata, skb);
+ }
+ 
+-void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
++void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn)
+ {
++	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ 	struct ieee80211_local *local = sdata->local;
+ 	struct sk_buff *skb;
+ 	struct ieee80211_bar *bar;
+@@ -138,6 +139,7 @@ void ieee80211_send_bar(struct ieee80211
+ 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
+ 	ieee80211_tx_skb(sdata, skb);
+ }
++EXPORT_SYMBOL(ieee80211_send_bar);
+ 
+ void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
+ 			     struct tid_ampdu_tx *tid_tx)
+--- a/include/net/mac80211.h
++++ b/include/net/mac80211.h
+@@ -3007,6 +3007,19 @@ void ieee80211_remain_on_channel_expired
+ void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
+ 				  const u8 *addr);
+ 
++/**
++ * ieee80211_send_bar - send a BlockAckReq frame
++ *
++ * can be used to flush pending frames from the peer's aggregation reorder
++ * buffer.
++ *
++ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
++ * @ra: the peer's destination address
++ * @tid: the TID of the aggregation session
++ * @ssn: the new starting sequence number for the receiver
++ */
++void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn);
++
+ /* Rate control API */
+ 
+ /**
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -1225,7 +1225,6 @@ struct ieee80211_tx_status_rtap_hdr {
+ void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
+ 				       struct ieee80211_ht_cap *ht_cap_ie,
+ 				       struct ieee80211_sta_ht_cap *ht_cap);
+-void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn);
+ void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
+ 			  const u8 *da, u16 tid,
+ 			  u16 initiator, u16 reason_code);
+--- a/net/mac80211/status.c
++++ b/net/mac80211/status.c
+@@ -239,7 +239,7 @@ void ieee80211_tx_status(struct ieee8021
+ 			tid = qc[0] & 0xf;
+ 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
+ 						& IEEE80211_SCTL_SEQ);
+-			ieee80211_send_bar(sta->sdata, hdr->addr1,
++			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
+ 					   tid, ssn);
+ 		}
+ 
diff --git a/package/mac80211/patches/571-ath9k_send_bar_fix.patch b/package/mac80211/patches/571-ath9k_send_bar_fix.patch
new file mode 100644
index 000000000..eed9d214a
--- /dev/null
+++ b/package/mac80211/patches/571-ath9k_send_bar_fix.patch
@@ -0,0 +1,149 @@
+--- a/drivers/net/wireless/ath/ath9k/ath9k.h
++++ b/drivers/net/wireless/ath/ath9k/ath9k.h
+@@ -275,7 +275,6 @@ struct ath_tx_control {
+ 
+ #define ATH_TX_ERROR        0x01
+ #define ATH_TX_XRETRY       0x02
+-#define ATH_TX_BAR          0x04
+ 
+ /**
+  * @txq_map:  Index is mac80211 queue number.  This is
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -1801,6 +1801,7 @@ static int ath9k_sta_add(struct ieee8021
+ 	struct ieee80211_key_conf ps_key = { };
+ 
+ 	ath_node_attach(sc, sta);
++	an->vif = vif;
+ 
+ 	if (vif->type != NL80211_IFTYPE_AP &&
+ 	    vif->type != NL80211_IFTYPE_AP_VLAN)
+--- a/drivers/net/wireless/ath/ath9k/xmit.c
++++ b/drivers/net/wireless/ath/ath9k/xmit.c
+@@ -51,7 +51,7 @@ static void ath_tx_send_normal(struct at
+ 			       struct list_head *bf_head);
+ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,
+ 				struct ath_txq *txq, struct list_head *bf_q,
+-				struct ath_tx_status *ts, int txok, int sendbar);
++				struct ath_tx_status *ts, int txok);
+ static void ath_tx_txqaddbuf(struct ath_softc *sc, struct ath_txq *txq,
+ 			     struct list_head *head, bool internal);
+ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf, int len);
+@@ -166,7 +166,7 @@ static void ath_tx_flush_tid(struct ath_
+ 		fi = get_frame_info(bf->bf_mpdu);
+ 		if (fi->retries) {
+ 			ath_tx_update_baw(sc, tid, fi->seqno);
+-			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0, 1);
++			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
+ 		} else {
+ 			ath_tx_send_normal(sc, txq, NULL, &bf_head);
+ 		}
+@@ -238,7 +238,7 @@ static void ath_tid_drain(struct ath_sof
+ 			ath_tx_update_baw(sc, tid, fi->seqno);
+ 
+ 		spin_unlock(&txq->axq_lock);
+-		ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0, 0);
++		ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
+ 		spin_lock(&txq->axq_lock);
+ 	}
+ 
+@@ -381,8 +381,7 @@ static void ath_tx_complete_aggr(struct 
+ 				list_move_tail(&bf->list, &bf_head);
+ 
+ 			ath_tx_rc_status(sc, bf, ts, 1, 1, 0, false);
+-			ath_tx_complete_buf(sc, bf, txq, &bf_head, ts,
+-				0, 0);
++			ath_tx_complete_buf(sc, bf, txq, &bf_head, ts, 0);
+ 
+ 			bf = bf_next;
+ 		}
+@@ -426,7 +425,7 @@ static void ath_tx_complete_aggr(struct 
+ 
+ 	ath_tx_count_frames(sc, bf, ts, txok, &nframes, &nbad);
+ 	while (bf) {
+-		txfail = txpending = sendbar = 0;
++		txfail = txpending = 0;
+ 		bf_next = bf->bf_next;
+ 
+ 		skb = bf->bf_mpdu;
+@@ -489,7 +488,7 @@ static void ath_tx_complete_aggr(struct 
+ 			}
+ 
+ 			ath_tx_complete_buf(sc, bf, txq, &bf_head, ts,
+-				!txfail, sendbar);
++				!txfail);
+ 		} else {
+ 			/* retry the un-acked ones */
+ 			ath9k_hw_set_clrdmask(sc->sc_ah, bf->bf_desc, false);
+@@ -514,7 +513,7 @@ static void ath_tx_complete_aggr(struct 
+ 								nbad, 0, false);
+ 						ath_tx_complete_buf(sc, bf, txq,
+ 								    &bf_head,
+-								    ts, 0, 0);
++								    ts, 0);
+ 						break;
+ 					}
+ 
+@@ -564,6 +563,9 @@ static void ath_tx_complete_aggr(struct 
+ 		}
+ 	}
+ 
++	if (sendbar || (tid->state & AGGR_CLEANUP))
++		ieee80211_send_bar(an->vif, sta->addr, tidno, tid->seq_start << 4);
++
+ 	rcu_read_unlock();
+ 
+ 	if (needreset)
+@@ -900,6 +902,7 @@ void ath_tx_aggr_stop(struct ath_softc *
+ 	spin_unlock_bh(&txq->axq_lock);
+ 
+ 	ath_tx_flush_tid(sc, txtid);
++	ieee80211_send_bar(an->vif, sta->addr, tid, txtid->seq_start << 4);
+ }
+ 
+ bool ath_tx_aggr_sleep(struct ath_softc *sc, struct ath_node *an)
+@@ -1178,7 +1181,7 @@ static void ath_drain_txq_list(struct at
+ 			ath_tx_complete_aggr(sc, txq, bf, &bf_head, &ts, 0,
+ 					     retry_tx);
+ 		else
+-			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0, 0);
++			ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
+ 		spin_lock_bh(&txq->axq_lock);
+ 	}
+ }
+@@ -1885,9 +1888,6 @@ static void ath_tx_complete(struct ath_s
+ 
+ 	ath_dbg(common, ATH_DBG_XMIT, "TX complete: skb: %p\n", skb);
+ 
+-	if (tx_flags & ATH_TX_BAR)
+-		tx_info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
+-
+ 	if (!(tx_flags & (ATH_TX_ERROR | ATH_TX_XRETRY))) {
+ 		/* Frame was ACKed */
+ 		tx_info->flags |= IEEE80211_TX_STAT_ACK;
+@@ -1932,15 +1932,12 @@ static void ath_tx_complete(struct ath_s
+ 
+ static void ath_tx_complete_buf(struct ath_softc *sc, struct ath_buf *bf,
+ 				struct ath_txq *txq, struct list_head *bf_q,
+-				struct ath_tx_status *ts, int txok, int sendbar)
++				struct ath_tx_status *ts, int txok)
+ {
+ 	struct sk_buff *skb = bf->bf_mpdu;
+ 	unsigned long flags;
+ 	int tx_flags = 0;
+ 
+-	if (sendbar)
+-		tx_flags = ATH_TX_BAR;
+-
+ 	if (!txok) {
+ 		tx_flags |= ATH_TX_ERROR;
+ 
+@@ -2056,7 +2053,7 @@ static void ath_tx_process_buffer(struct
+ 		if (ts->ts_status & ATH9K_TXERR_XRETRY)
+ 			bf->bf_state.bf_type |= BUF_XRETRY;
+ 		ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok, true);
+-		ath_tx_complete_buf(sc, bf, txq, bf_head, ts, txok, 0);
++		ath_tx_complete_buf(sc, bf, txq, bf_head, ts, txok);
+ 	} else
+ 		ath_tx_complete_aggr(sc, txq, bf, bf_head, ts, txok, true);
+