[PATCH 14/23] wifi: mt76: gate NAN unicast mgmt by peer availability via STA queues

[Sean Wang <sean.wang@kernel.org>]

From: Jacobs Wu <jacobs.wu@mediatek.com>

Host-initiated NAN action frames (NDP Request/Response/Confirm) were
sent on MT_TXQ_PSD -> MT_LMAC_ALTX0 through the interface WTBL: a
force-TX path with no relation to the NAN timeline. With a partial
availability bitmap the peer is off-channel most of the time, so the
15-retry burst (~11-51ms) regularly misses the peer entirely and NDP
setup fails probabilistically (half ~2/3, quarter ~0), and per spec
unicast NAN mgmt must be transmitted within the peer availability
windows.

Route unicast NAN mgmt through the peer STA WTBL on its AC queue
instead: the FW pauses/resumes the peer WTBL AC queues according to
the peer schedule record (the committed-window intersection computed
by the supplicant), which is the same gating the NDP data path already
relies on. Multicast NAN mgmt (and unicast without a peer STA) keeps
using the interface WTBL, which has no pause driver.

Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Jacobs Wu <jacobs.wu@mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/tx.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 3707ee19e4ae..a3688b9fe635 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -681,6 +681,18 @@ mt76_txq_schedule_pending_wcid(struct mt76_phy *phy, struct mt76_wcid *wcid,
 		     head == &wcid->tx_offchannel))
 			qid = MT_TXQ_PSD;
 
+		/* NAN unicast mgmt (NAFs) must stay on its AC queue: the
+		 * PSD path maps to the ALTX (force-TX) hardware queue,
+		 * which escapes the per-peer STA_PAUSE availability gating
+		 * and transmits regardless of the peer's committed bitmap.
+		 */
+		if (qid == MT_TXQ_PSD && wcid->sta &&
+		    info->control.vif &&
+		    (info->control.vif->type == NL80211_IFTYPE_NAN ||
+		     info->control.vif->type == NL80211_IFTYPE_NAN_DATA) &&
+		    head != &wcid->tx_offchannel)
+			qid = skb_get_queue_mapping(skb);
+
 		q = phy->q_tx[qid];
 		if (mt76_txq_stopped(q) || test_bit(MT76_RESET, &phy->state)) {
 			ret = -1;
-- 
2.43.0