2011-12-14 21:08:19

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 1/6] ath9k: change maximum software retransmission handling

Instead of limiting a subframe to 10 A-MPDU software transmission attempts,
count hardware retransmissions as well and raise the limit a bit. That way
there will be fewer software retransmission attempts when traffic suffers
from lots of hardware retransmissions.

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 2 +-
drivers/net/wireless/ath/ath9k/xmit.c | 15 ++++++++++++---
2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index afc156a..fa6c905 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -542,7 +542,7 @@ struct ath_ant_comb {
#define DEFAULT_CACHELINE 32
#define ATH_REGCLASSIDS_MAX 10
#define ATH_CABQ_READY_TIME 80 /* % of beacon interval */
-#define ATH_MAX_SW_RETRIES 10
+#define ATH_MAX_SW_RETRIES 30
#define ATH_CHAN_MAX 255

#define ATH_TXPOWER_MAX 100 /* .5 dBm units */
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 9e65c31..a46b4e2 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -264,14 +264,17 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
}

static void ath_tx_set_retry(struct ath_softc *sc, struct ath_txq *txq,
- struct sk_buff *skb)
+ struct sk_buff *skb, int count)
{
struct ath_frame_info *fi = get_frame_info(skb);
struct ath_buf *bf = fi->bf;
struct ieee80211_hdr *hdr;
+ int prev = fi->retries;

TX_STAT_INC(txq->axq_qnum, a_retries);
- if (fi->retries++ > 0)
+ fi->retries += count;
+
+ if (prev > 0)
return;

hdr = (struct ieee80211_hdr *)skb->data;
@@ -379,6 +382,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
int nframes;
u8 tidno;
bool flush = !!(ts->ts_status & ATH9K_TX_FLUSH);
+ int i, retries;

skb = bf->bf_mpdu;
hdr = (struct ieee80211_hdr *)skb->data;
@@ -387,6 +391,10 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,

memcpy(rates, tx_info->control.rates, sizeof(rates));

+ retries = ts->ts_longretry + 1;
+ for (i = 0; i < ts->ts_rateindex; i++)
+ retries += rates[i].count;
+
rcu_read_lock();

sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr1, hdr->addr2);
@@ -471,7 +479,8 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
txpending = 1;
} else if (fi->retries < ATH_MAX_SW_RETRIES) {
if (txok || !an->sleeping)
- ath_tx_set_retry(sc, txq, bf->bf_mpdu);
+ ath_tx_set_retry(sc, txq, bf->bf_mpdu,
+ retries);

txpending = 1;
} else {
--
1.7.3.2



2011-12-14 21:08:19

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 4/6] ath9k: remove bogus sequence number increment

tid->seq_next is initialized on A-MPDU start anyway, and the comment next
to this chunk of code seems to be bogus as well.

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/xmit.c | 4 ----
1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index b1a37d2..8f38efb 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1729,10 +1729,6 @@ static void ath_tx_send_normal(struct ath_softc *sc, struct ath_txq *txq,
list_add_tail(&bf->list, &bf_head);
bf->bf_state.bf_type = 0;

- /* update starting sequence number for subsequent ADDBA request */
- if (tid)
- INCR(tid->seq_start, IEEE80211_SEQ_MAX);
-
bf->bf_lastbf = bf;
ath_tx_fill_desc(sc, bf, txq, fi->framelen);
ath_tx_txqaddbuf(sc, txq, &bf_head, false);
--
1.7.3.2


2011-12-14 21:08:19

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 6/6] ath9k: avoid retransmitting aggregation frames that a BAR was sent for

The receiver will discard them anyway.

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 1 +
drivers/net/wireless/ath/ath9k/xmit.c | 27 ++++++++++++++++++++++++---
2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 6beaff5..130e5db 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -241,6 +241,7 @@ struct ath_atx_tid {
struct ath_node *an;
struct ath_atx_ac *ac;
unsigned long tx_buf[BITS_TO_LONGS(ATH_TID_MAX_BUFS)];
+ int bar_index;
u16 seq_start;
u16 seq_next;
u16 baw_size;
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 8766796..23e80e6 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -206,6 +206,8 @@ static void ath_tx_update_baw(struct ath_softc *sc, struct ath_atx_tid *tid,
while (tid->baw_head != tid->baw_tail && !test_bit(tid->baw_head, tid->tx_buf)) {
INCR(tid->seq_start, IEEE80211_SEQ_MAX);
INCR(tid->baw_head, ATH_TID_MAX_BUFS);
+ if (tid->bar_index >= 0)
+ tid->bar_index--;
}
}

@@ -263,6 +265,7 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,

tid->seq_next = tid->seq_start;
tid->baw_tail = tid->baw_head;
+ tid->bar_index = -1;
}

static void ath_tx_set_retry(struct ath_softc *sc, struct ath_txq *txq,
@@ -551,8 +554,12 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
bf = bf_next;
}

- if (bar_index >= 0)
+ if (bar_index >= 0) {
+ u16 bar_seq = ATH_BA_INDEX2SEQ(seq_first, bar_index);
ath_send_bar(tid, ATH_BA_INDEX2SEQ(seq_first, bar_index + 1));
+ if (BAW_WITHIN(tid->seq_start, tid->baw_size, bar_seq))
+ tid->bar_index = ATH_BA_INDEX(tid->seq_start, bar_seq);
+ }

/* prepend un-acked frames to the beginning of the pending frame queue */
if (!skb_queue_empty(&bf_pending)) {
@@ -779,8 +786,6 @@ static enum ATH_AGGR_STATUS ath_tx_form_aggr(struct ath_softc *sc,

bf->bf_state.bf_type = BUF_AMPDU | BUF_AGGR;
seqno = bf->bf_state.seqno;
- if (!bf_first)
- bf_first = bf;

/* do not step over block-ack window */
if (!BAW_WITHIN(tid->seq_start, tid->baw_size, seqno)) {
@@ -788,6 +793,21 @@ static enum ATH_AGGR_STATUS ath_tx_form_aggr(struct ath_softc *sc,
break;
}

+ if (tid->bar_index > ATH_BA_INDEX(tid->seq_start, seqno)) {
+ struct ath_tx_status ts = {};
+ struct list_head bf_head;
+
+ INIT_LIST_HEAD(&bf_head);
+ list_add(&bf->list, &bf_head);
+ __skb_unlink(skb, &tid->buf_q);
+ ath_tx_update_baw(sc, tid, seqno);
+ ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
+ continue;
+ }
+
+ if (!bf_first)
+ bf_first = bf;
+
if (!rl) {
aggr_limit = ath_lookup_rate(sc, bf, tid);
rl = 1;
@@ -1130,6 +1150,7 @@ int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
txtid->state |= AGGR_ADDBA_PROGRESS;
txtid->paused = true;
*ssn = txtid->seq_start = txtid->seq_next;
+ txtid->bar_index = -1;

memset(txtid->tx_buf, 0, sizeof(txtid->tx_buf));
txtid->baw_head = txtid->baw_tail = 0;
--
1.7.3.2


2011-12-14 21:08:19

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 2/6] ath9k: reduce the number of unnecessary BAR tx packets

When processing A-MPDU tx status, only send a BAR for the failed packet
with the highest sequence number.

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 6 ++-
drivers/net/wireless/ath/ath9k/debug.c | 2 +-
drivers/net/wireless/ath/ath9k/main.c | 2 +-
drivers/net/wireless/ath/ath9k/xmit.c | 50 +++++++++++++++++++------------
4 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index fa6c905..6beaff5 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -159,6 +159,9 @@ void ath_descdma_cleanup(struct ath_softc *sc, struct ath_descdma *dd,
/* return block-ack bitmap index given sequence and starting sequence */
#define ATH_BA_INDEX(_st, _seq) (((_seq) - (_st)) & (IEEE80211_SEQ_MAX - 1))

+/* return the seqno for _start + _offset */
+#define ATH_BA_INDEX2SEQ(_seq, _offset) (((_seq) + (_offset)) & (IEEE80211_SEQ_MAX - 1))
+
/* returns delimiter padding required given the packet length */
#define ATH_AGGR_GET_NDELIM(_len) \
(((_len) >= ATH_AGGR_MINPLEN) ? 0 : \
@@ -252,9 +255,9 @@ struct ath_atx_tid {
struct ath_node {
#ifdef CONFIG_ATH9K_DEBUGFS
struct list_head list; /* for sc->nodes */
+#endif
struct ieee80211_sta *sta; /* station struct we're part of */
struct ieee80211_vif *vif; /* interface with which we're associated */
-#endif
struct ath_atx_tid tid[WME_NUM_TID];
struct ath_atx_ac ac[WME_NUM_AC];
int ps_key;
@@ -276,7 +279,6 @@ struct ath_tx_control {
};

#define ATH_TX_ERROR 0x01
-#define ATH_TX_BAR 0x02

/**
* @txq_map: Index is mac80211 queue number. This is
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index 6fb719d..5cb8cce 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -856,7 +856,7 @@ void ath_debug_stat_tx(struct ath_softc *sc, struct ath_buf *bf,
sc->debug.stats.txstats[qnum].tx_bytes_all += bf->bf_mpdu->len;

if (bf_isampdu(bf)) {
- if (flags & ATH_TX_BAR)
+ if (flags & ATH_TX_ERROR)
TX_STAT_INC(qnum, a_xretries);
else
TX_STAT_INC(qnum, a_completed);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 7d92004..4475b0d 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -644,9 +644,9 @@ static void ath_node_attach(struct ath_softc *sc, struct ieee80211_sta *sta,
spin_lock(&sc->nodes_lock);
list_add(&an->list, &sc->nodes);
spin_unlock(&sc->nodes_lock);
+#endif
an->sta = sta;
an->vif = vif;
-#endif
if (sc->sc_flags & SC_OP_TXAGGR) {
ath_tx_node_init(sc, an);
an->maxampdu = 1 << (IEEE80211_HT_MAX_AMPDU_FACTOR +
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index a46b4e2..649a11e 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -53,7 +53,7 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
int tx_flags, struct ath_txq *txq);
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_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
@@ -150,6 +150,12 @@ static struct ath_frame_info *get_frame_info(struct sk_buff *skb)
return (struct ath_frame_info *) &tx_info->rate_driver_data[0];
}

+static void ath_send_bar(struct ath_atx_tid *tid, u16 seqno)
+{
+ ieee80211_send_bar(tid->an->vif, tid->an->sta->addr, tid->tidno,
+ seqno << IEEE80211_SEQ_SEQ_SHIFT);
+}
+
static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
{
struct ath_txq *txq = tid->ac->txq;
@@ -158,6 +164,7 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
struct list_head bf_head;
struct ath_tx_status ts;
struct ath_frame_info *fi;
+ bool sendbar = false;

INIT_LIST_HEAD(&bf_head);

@@ -172,7 +179,8 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
if (bf && fi->retries) {
list_add_tail(&bf->list, &bf_head);
ath_tx_update_baw(sc, tid, bf->bf_state.seqno);
- ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0, 1);
+ ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
+ sendbar = true;
} else {
ath_tx_send_normal(sc, txq, NULL, skb);
}
@@ -185,6 +193,9 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
}

spin_unlock_bh(&txq->axq_lock);
+
+ if (sendbar)
+ ath_send_bar(tid, tid->seq_start);
}

static void ath_tx_update_baw(struct ath_softc *sc, struct ath_atx_tid *tid,
@@ -255,7 +266,7 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
ath_tx_update_baw(sc, tid, bf->bf_state.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);
}

@@ -373,7 +384,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
struct ath_buf *bf_next, *bf_last = bf->bf_lastbf;
struct list_head bf_head;
struct sk_buff_head bf_pending;
- u16 seq_st = 0, acked_cnt = 0, txfail_cnt = 0;
+ u16 seq_st = 0, acked_cnt = 0, txfail_cnt = 0, seq_first;
u32 ba[WME_BA_BMP_SIZE >> 5];
int isaggr, txfail, txpending, sendbar = 0, needreset = 0, nbad = 0;
bool rc_update = true;
@@ -383,6 +394,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
u8 tidno;
bool flush = !!(ts->ts_status & ATH9K_TX_FLUSH);
int i, retries;
+ int bar_index = -1;

skb = bf->bf_mpdu;
hdr = (struct ieee80211_hdr *)skb->data;
@@ -408,8 +420,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
if (!bf->bf_stale || bf_next != NULL)
list_move_tail(&bf->list, &bf_head);

- 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;
}
@@ -419,6 +430,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
an = (struct ath_node *)sta->drv_priv;
tidno = ieee80211_get_qos_ctl(hdr)[0] & IEEE80211_QOS_CTL_TID_MASK;
tid = ATH_AN_2_TID(an, tidno);
+ seq_first = tid->seq_start;

/*
* The hardware occasionally sends a tx status for the wrong TID.
@@ -485,8 +497,9 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
txpending = 1;
} else {
txfail = 1;
- sendbar = 1;
txfail_cnt++;
+ bar_index = max_t(int, bar_index,
+ ATH_BA_INDEX(seq_first, seqno));
}
}

@@ -515,7 +528,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
}

ath_tx_complete_buf(sc, bf, txq, &bf_head, ts,
- !txfail, sendbar);
+ !txfail);
} else {
/* retry the un-acked ones */
if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)) {
@@ -535,8 +548,10 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,

ath_tx_complete_buf(sc, bf, txq,
&bf_head,
- ts, 0,
- !flush);
+ ts, 0);
+ bar_index = max_t(int, bar_index,
+ ATH_BA_INDEX(seq_first,
+ seqno));
break;
}

@@ -554,6 +569,9 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
bf = bf_next;
}

+ if (bar_index >= 0)
+ ath_send_bar(tid, ATH_BA_INDEX2SEQ(seq_first, bar_index + 1));
+
/* prepend un-acked frames to the beginning of the pending frame queue */
if (!skb_queue_empty(&bf_pending)) {
if (an->sleeping)
@@ -1441,7 +1459,7 @@ static void ath_drain_txq_list(struct ath_softc *sc, struct ath_txq *txq,
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);
}
}
@@ -1945,9 +1963,6 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,

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))
/* Frame was ACKed */
tx_info->flags |= IEEE80211_TX_STAT_ACK;
@@ -1991,16 +2006,13 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,

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;
struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
unsigned long flags;
int tx_flags = 0;

- if (sendbar)
- tx_flags = ATH_TX_BAR;
-
if (!txok)
tx_flags |= ATH_TX_ERROR;

@@ -2107,7 +2119,7 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,

if (!bf_isampdu(bf)) {
ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok);
- 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);

--
1.7.3.2


2011-12-14 21:08:19

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 3/6] ath9k: reduce indentation level in a few places

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/xmit.c | 125 ++++++++++++++++-----------------
1 files changed, 60 insertions(+), 65 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 649a11e..b1a37d2 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -480,27 +480,25 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
} else if (!isaggr && txok) {
/* transmit completion */
acked_cnt++;
+ } else if ((tid->state & AGGR_CLEANUP) || !retry) {
+ /*
+ * cleanup in progress, just fail
+ * the un-acked sub-frames
+ */
+ txfail = 1;
+ } else if (flush) {
+ txpending = 1;
+ } else if (fi->retries < ATH_MAX_SW_RETRIES) {
+ if (txok || !an->sleeping)
+ ath_tx_set_retry(sc, txq, bf->bf_mpdu,
+ retries);
+
+ txpending = 1;
} else {
- if ((tid->state & AGGR_CLEANUP) || !retry) {
- /*
- * cleanup in progress, just fail
- * the un-acked sub-frames
- */
- txfail = 1;
- } else if (flush) {
- txpending = 1;
- } else if (fi->retries < ATH_MAX_SW_RETRIES) {
- if (txok || !an->sleeping)
- ath_tx_set_retry(sc, txq, bf->bf_mpdu,
- retries);
-
- txpending = 1;
- } else {
- txfail = 1;
- txfail_cnt++;
- bar_index = max_t(int, bar_index,
- ATH_BA_INDEX(seq_first, seqno));
- }
+ txfail = 1;
+ txfail_cnt++;
+ bar_index = max_t(int, bar_index,
+ ATH_BA_INDEX(seq_first, seqno));
}

/*
@@ -531,32 +529,29 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
!txfail);
} else {
/* retry the un-acked ones */
- if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)) {
- if (bf->bf_next == NULL && bf_last->bf_stale) {
- struct ath_buf *tbf;
-
- tbf = ath_clone_txbuf(sc, bf_last);
- /*
- * Update tx baw and complete the
- * frame with failed status if we
- * run out of tx buf.
- */
- if (!tbf) {
- spin_lock_bh(&txq->axq_lock);
- ath_tx_update_baw(sc, tid, seqno);
- spin_unlock_bh(&txq->axq_lock);
-
- ath_tx_complete_buf(sc, bf, txq,
- &bf_head,
- ts, 0);
- bar_index = max_t(int, bar_index,
- ATH_BA_INDEX(seq_first,
- seqno));
- break;
- }
-
- fi->bf = tbf;
+ if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) &&
+ bf->bf_next == NULL && bf_last->bf_stale) {
+ struct ath_buf *tbf;
+
+ tbf = ath_clone_txbuf(sc, bf_last);
+ /*
+ * Update tx baw and complete the
+ * frame with failed status if we
+ * run out of tx buf.
+ */
+ if (!tbf) {
+ spin_lock_bh(&txq->axq_lock);
+ ath_tx_update_baw(sc, tid, seqno);
+ spin_unlock_bh(&txq->axq_lock);
+
+ ath_tx_complete_buf(sc, bf, txq,
+ &bf_head, ts, 0);
+ bar_index = max_t(int, bar_index,
+ ATH_BA_INDEX(seq_first, seqno));
+ break;
}
+
+ fi->bf = tbf;
}

/*
@@ -644,24 +639,26 @@ static u32 ath_lookup_rate(struct ath_softc *sc, struct ath_buf *bf,
max_4ms_framelen = ATH_AMPDU_LIMIT_MAX;

for (i = 0; i < 4; i++) {
- if (rates[i].count) {
- int modeidx;
- if (!(rates[i].flags & IEEE80211_TX_RC_MCS)) {
- legacy = 1;
- break;
- }
-
- if (rates[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
- modeidx = MCS_HT40;
- else
- modeidx = MCS_HT20;
+ int modeidx;

- if (rates[i].flags & IEEE80211_TX_RC_SHORT_GI)
- modeidx++;
+ if (!rates[i].count)
+ continue;

- frmlen = ath_max_4ms_framelen[modeidx][rates[i].idx];
- max_4ms_framelen = min(max_4ms_framelen, frmlen);
+ if (!(rates[i].flags & IEEE80211_TX_RC_MCS)) {
+ legacy = 1;
+ break;
}
+
+ if (rates[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
+ modeidx = MCS_HT40;
+ else
+ modeidx = MCS_HT20;
+
+ if (rates[i].flags & IEEE80211_TX_RC_SHORT_GI)
+ modeidx++;
+
+ frmlen = ath_max_4ms_framelen[modeidx][rates[i].idx];
+ max_4ms_framelen = min(max_4ms_framelen, frmlen);
}

/*
@@ -1587,11 +1584,9 @@ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
break;
}

- if (!list_empty(&ac->tid_q)) {
- if (!ac->sched) {
- ac->sched = true;
- list_add_tail(&ac->list, &txq->axq_acq);
- }
+ if (!list_empty(&ac->tid_q) && !ac->sched) {
+ ac->sched = true;
+ list_add_tail(&ac->list, &txq->axq_acq);
}

if (ac == last_ac ||
--
1.7.3.2


2011-12-14 21:08:20

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 5/6] ath9k: simplify tx locking

Instead of releasing and taking back the lock over and over again in the
tx path, hold the lock a bit longer, requiring much fewer lock/unlock pairs.
This makes locking much easier to review and should not have any noticeable
performance/latency impact.

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/xmit.c | 39 ++++----------------------------
1 files changed, 5 insertions(+), 34 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 8f38efb..8766796 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -169,13 +169,11 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
INIT_LIST_HEAD(&bf_head);

memset(&ts, 0, sizeof(ts));
- spin_lock_bh(&txq->axq_lock);

while ((skb = __skb_dequeue(&tid->buf_q))) {
fi = get_frame_info(skb);
bf = fi->bf;

- spin_unlock_bh(&txq->axq_lock);
if (bf && fi->retries) {
list_add_tail(&bf->list, &bf_head);
ath_tx_update_baw(sc, tid, bf->bf_state.seqno);
@@ -184,7 +182,6 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
} else {
ath_tx_send_normal(sc, txq, NULL, skb);
}
- spin_lock_bh(&txq->axq_lock);
}

if (tid->baw_head == tid->baw_tail) {
@@ -192,8 +189,6 @@ static void ath_tx_flush_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
tid->state &= ~AGGR_CLEANUP;
}

- spin_unlock_bh(&txq->axq_lock);
-
if (sendbar)
ath_send_bar(tid, tid->seq_start);
}
@@ -254,9 +249,7 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
bf = fi->bf;

if (!bf) {
- spin_unlock(&txq->axq_lock);
ath_tx_complete(sc, skb, ATH_TX_ERROR, txq);
- spin_lock(&txq->axq_lock);
continue;
}

@@ -265,9 +258,7 @@ static void ath_tid_drain(struct ath_softc *sc, struct ath_txq *txq,
if (fi->retries)
ath_tx_update_baw(sc, tid, bf->bf_state.seqno);

- spin_unlock(&txq->axq_lock);
ath_tx_complete_buf(sc, bf, txq, &bf_head, &ts, 0);
- spin_lock(&txq->axq_lock);
}

tid->seq_next = tid->seq_start;
@@ -515,9 +506,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
* complete the acked-ones/xretried ones; update
* block-ack window
*/
- spin_lock_bh(&txq->axq_lock);
ath_tx_update_baw(sc, tid, seqno);
- spin_unlock_bh(&txq->axq_lock);

if (rc_update && (acked_cnt == 1 || txfail_cnt == 1)) {
memcpy(tx_info->control.rates, rates, sizeof(rates));
@@ -540,9 +529,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
* run out of tx buf.
*/
if (!tbf) {
- spin_lock_bh(&txq->axq_lock);
ath_tx_update_baw(sc, tid, seqno);
- spin_unlock_bh(&txq->axq_lock);

ath_tx_complete_buf(sc, bf, txq,
&bf_head, ts, 0);
@@ -572,7 +559,6 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
if (an->sleeping)
ieee80211_sta_set_buffered(sta, tid->tidno, true);

- spin_lock_bh(&txq->axq_lock);
skb_queue_splice(&bf_pending, &tid->buf_q);
if (!an->sleeping) {
ath_tx_queue_tid(txq, tid);
@@ -580,7 +566,6 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
if (ts->ts_status & ATH9K_TXERR_FILT)
tid->ac->clear_ps_filter = true;
}
- spin_unlock_bh(&txq->axq_lock);
}

if (tid->state & AGGR_CLEANUP)
@@ -1179,9 +1164,9 @@ void ath_tx_aggr_stop(struct ath_softc *sc, struct ieee80211_sta *sta, u16 tid)
txtid->state |= AGGR_CLEANUP;
else
txtid->state &= ~AGGR_ADDBA_COMPLETE;
- spin_unlock_bh(&txq->axq_lock);

ath_tx_flush_tid(sc, txtid);
+ spin_unlock_bh(&txq->axq_lock);
}

void ath_tx_aggr_sleep(struct ieee80211_sta *sta, struct ath_softc *sc,
@@ -1423,8 +1408,6 @@ static bool bf_is_ampdu_not_probing(struct ath_buf *bf)

static void ath_drain_txq_list(struct ath_softc *sc, struct ath_txq *txq,
struct list_head *list, bool retry_tx)
- __releases(txq->axq_lock)
- __acquires(txq->axq_lock)
{
struct ath_buf *bf, *lastbf;
struct list_head bf_head;
@@ -1451,13 +1434,11 @@ static void ath_drain_txq_list(struct ath_softc *sc, struct ath_txq *txq,
if (bf_is_ampdu_not_probing(bf))
txq->axq_ampdu_depth--;

- spin_unlock_bh(&txq->axq_lock);
if (bf_isampdu(bf))
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);
- spin_lock_bh(&txq->axq_lock);
}
}

@@ -1836,7 +1817,6 @@ static void ath_tx_start_dma(struct ath_softc *sc, struct sk_buff *skb,
struct ath_buf *bf;
u8 tidno;

- spin_lock_bh(&txctl->txq->axq_lock);
if ((sc->sc_flags & SC_OP_TXAGGR) && txctl->an &&
ieee80211_is_data_qos(hdr->frame_control)) {
tidno = ieee80211_get_qos_ctl(hdr)[0] &
@@ -1855,7 +1835,7 @@ static void ath_tx_start_dma(struct ath_softc *sc, struct sk_buff *skb,
} else {
bf = ath_tx_setup_buffer(sc, txctl->txq, tid, skb);
if (!bf)
- goto out;
+ return;

bf->bf_state.bfs_paprd = txctl->paprd;

@@ -1864,9 +1844,6 @@ static void ath_tx_start_dma(struct ath_softc *sc, struct sk_buff *skb,

ath_tx_send_normal(sc, txctl->txq, tid, skb);
}
-
-out:
- spin_unlock_bh(&txctl->txq->axq_lock);
}

/* Upon failure caller should free skb */
@@ -1933,9 +1910,11 @@ int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
ieee80211_stop_queue(sc->hw, q);
txq->stopped = 1;
}
- spin_unlock_bh(&txq->axq_lock);

ath_tx_start_dma(sc, skb, txctl);
+
+ spin_unlock_bh(&txq->axq_lock);
+
return 0;
}

@@ -1981,7 +1960,6 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,

q = skb_get_queue_mapping(skb);
if (txq == sc->tx.txq_map[q]) {
- spin_lock_bh(&txq->axq_lock);
if (WARN_ON(--txq->pending_frames < 0))
txq->pending_frames = 0;

@@ -1989,7 +1967,6 @@ static void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
ieee80211_wake_queue(sc->hw, q);
txq->stopped = 0;
}
- spin_unlock_bh(&txq->axq_lock);
}

ieee80211_tx_status(hw, skb);
@@ -2095,8 +2072,6 @@ static void ath_tx_rc_status(struct ath_softc *sc, struct ath_buf *bf,
static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
struct ath_tx_status *ts, struct ath_buf *bf,
struct list_head *bf_head)
- __releases(txq->axq_lock)
- __acquires(txq->axq_lock)
{
int txok;

@@ -2106,16 +2081,12 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
if (bf_is_ampdu_not_probing(bf))
txq->axq_ampdu_depth--;

- spin_unlock_bh(&txq->axq_lock);
-
if (!bf_isampdu(bf)) {
ath_tx_rc_status(sc, bf, ts, 1, txok ? 0 : 1, txok);
ath_tx_complete_buf(sc, bf, txq, bf_head, ts, txok);
} else
ath_tx_complete_aggr(sc, txq, bf, bf_head, ts, txok, true);

- spin_lock_bh(&txq->axq_lock);
-
if (sc->sc_flags & SC_OP_TXAGGR)
ath_txq_schedule(sc, txq);
}
--
1.7.3.2