ath9k: fix queue depth check for forming new aggregates
To improve aggregation length, there should not be more than two fully formed
A-MPDU frames in the hardware queue. To ensure this, the code checks the tx
queue length before forming new A-MPDUs. This can reduce the throughput (or
maybe even starve out A-MPDU traffic) when too many non-aggregated frames are
in the queue.
Fix this by keeping track of pending A-MPDU frames (even when they're sent out
as single frames), but exclude rate control probing frames to improve
performance.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 96623695..332d1fe 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -838,7 +838,7 @@
ath_tx_txqaddbuf(sc, txq, &bf_q);
TX_STAT_INC(txq->axq_qnum, a_aggr);
- } while (txq->axq_depth < ATH_AGGR_MIN_QDEPTH &&
+ } while (txq->axq_ampdu_depth < ATH_AGGR_MIN_QDEPTH &&
status != ATH_AGGR_BAW_CLOSED);
}
@@ -999,6 +999,7 @@
INIT_LIST_HEAD(&txq->axq_acq);
spin_lock_init(&txq->axq_lock);
txq->axq_depth = 0;
+ txq->axq_ampdu_depth = 0;
txq->axq_tx_inprogress = false;
sc->tx.txqsetup |= 1<<qnum;
@@ -1068,6 +1069,12 @@
return 0;
}
+static bool bf_is_ampdu_not_probing(struct ath_buf *bf)
+{
+ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(bf->bf_mpdu);
+ return bf_isampdu(bf) && !(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
+}
+
/*
* Drain a given TX queue (could be Beacon or Data)
*
@@ -1126,7 +1133,8 @@
}
txq->axq_depth--;
-
+ if (bf_is_ampdu_not_probing(bf))
+ txq->axq_ampdu_depth--;
spin_unlock_bh(&txq->axq_lock);
if (bf_isampdu(bf))
@@ -1316,6 +1324,8 @@
ath9k_hw_txstart(ah, txq->axq_qnum);
}
txq->axq_depth++;
+ if (bf_is_ampdu_not_probing(bf))
+ txq->axq_ampdu_depth++;
}
static void ath_tx_send_ampdu(struct ath_softc *sc, struct ath_atx_tid *tid,
@@ -1336,7 +1346,7 @@
*/
if (!list_empty(&tid->buf_q) || tid->paused ||
!BAW_WITHIN(tid->seq_start, tid->baw_size, fi->seqno) ||
- txctl->txq->axq_depth >= ATH_AGGR_MIN_QDEPTH) {
+ txctl->txq->axq_ampdu_depth >= ATH_AGGR_MIN_QDEPTH) {
/*
* Add this frame to software queue for scheduling later
* for aggregation.
@@ -2040,6 +2050,9 @@
txq->axq_tx_inprogress = false;
if (bf_held)
list_del(&bf_held->list);
+
+ if (bf_is_ampdu_not_probing(bf))
+ txq->axq_ampdu_depth--;
spin_unlock_bh(&txq->axq_lock);
if (bf_held)
@@ -2168,6 +2181,8 @@
INCR(txq->txq_tailidx, ATH_TXFIFO_DEPTH);
txq->axq_depth--;
txq->axq_tx_inprogress = false;
+ if (bf_is_ampdu_not_probing(bf))
+ txq->axq_ampdu_depth--;
spin_unlock_bh(&txq->axq_lock);
txok = !(txs.ts_status & ATH9K_TXERR_MASK);