[PATCH RFC 1/3] ath10k: improve tx status reporting

[Sergey Ryazanov]

We use ieee80211_tx_status() to report each completed tx frame.
Internally, this function calls sta_info_get_by_addrs(), what has a
couple of drawbacks:
1. additional station lookup causes a performance degradation;
2. mac80211 can not properly account Ethernet encapsulated frames due
   to the inability to properly determine the destination (station) MAC
   address since ieee80211_tx_status() assumes the frame has a 802.11
   header.

The latter is especially destructive if we want to use hardware frames
encapsulation.

To fix both of these issues, replace ieee80211_tx_status() with
ieee80211_tx_status_ext() call and feed it station pointer from the tx
queue associated with the transmitted frame.

Tested-on: QCA9888 hw 2.0 10.4-3.9.0.2-00131
Signed-off-by: Sergey Ryazanov <ryazanov.s.a at gmail.com>
---
 drivers/net/wireless/ath/ath10k/txrx.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c
index 10123974c3da..72540434c75b 100644
--- a/drivers/net/wireless/ath/ath10k/txrx.c
+++ b/drivers/net/wireless/ath/ath10k/txrx.c
@@ -43,6 +43,7 @@ static void ath10k_report_offchan_tx(struct ath10k *ar, struct sk_buff *skb)
 int ath10k_txrx_tx_unref(struct ath10k_htt *htt,
 			 const struct htt_tx_done *tx_done)
 {
+	struct ieee80211_tx_status status;
 	struct ath10k *ar = htt->ar;
 	struct device *dev = ar->dev;
 	struct ieee80211_tx_info *info;
@@ -128,7 +129,16 @@ int ath10k_txrx_tx_unref(struct ath10k_htt *htt,
 		info->status.flags |= IEEE80211_TX_STATUS_ACK_SIGNAL_VALID;
 	}
 
-	ieee80211_tx_status(htt->ar->hw, msdu);
+	memset(&status, 0, sizeof(status));
+	status.skb = msdu;
+	status.info = info;
+
+	rcu_read_lock();
+	if (txq && txq->sta)
+		status.sta = txq->sta;
+	ieee80211_tx_status_ext(htt->ar->hw, &status);
+	rcu_read_unlock();
+
 	/* we do not own the msdu anymore */
 
 	return 0;
-- 
2.34.1