[PATCH v2] wifi: mt76: mt7921: fix skb leak by txs missing in AMSDU

[Deren Wu]

txs may be dropped if the frame is aggregated in AMSDU. When the problem
shows up, some SKBs would be hold in driver to cause network stopped
temporarily. Even if the problem can be recovered by txs timeout handling,
mt7921 still need to disable txs in AMSDU to avoid this issue.

Cc: stable at vger.kernel.org
Fixes: 163f4d22c118 ("mt76: mt7921: add MAC support")
Reviewed-by: Shayne Chen <shayne.chen at mediatek.com>
Signed-off-by: Deren Wu <deren.wu at mediatek.com>
---
v2: * update operation for booleans, not bitfields (suggested by Simon Horman)
    * rectify fixes tag for downstream backport
---
 drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
index ee0fbfcd07d6..a548b8debf5f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
@@ -495,6 +495,7 @@ void mt76_connac2_mac_write_txwi(struct mt76_dev *dev, __le32 *txwi,
 				    BSS_CHANGED_BEACON_ENABLED));
 	bool inband_disc = !!(changed & (BSS_CHANGED_UNSOL_BCAST_PROBE_RESP |
 					 BSS_CHANGED_FILS_DISCOVERY));
+	bool amsdu_en = wcid->amsdu;
 
 	if (vif) {
 		struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;
@@ -554,12 +555,14 @@ void mt76_connac2_mac_write_txwi(struct mt76_dev *dev, __le32 *txwi,
 	txwi[4] = 0;
 
 	val = FIELD_PREP(MT_TXD5_PID, pid);
-	if (pid >= MT_PACKET_ID_FIRST)
+	if (pid >= MT_PACKET_ID_FIRST) {
 		val |= MT_TXD5_TX_STATUS_HOST;
+		amsdu_en = amsdu_en && !is_mt7921(dev);
+	}
 
 	txwi[5] = cpu_to_le32(val);
 	txwi[6] = 0;
-	txwi[7] = wcid->amsdu ? cpu_to_le32(MT_TXD7_HW_AMSDU) : 0;
+	txwi[7] = amsdu_en ? cpu_to_le32(MT_TXD7_HW_AMSDU) : 0;
 
 	if (is_8023)
 		mt76_connac2_mac_write_txwi_8023(txwi, skb, wcid);
-- 
2.18.0