[PATCH v2] wifi: mt76: mt7925: fix AMPDU state handling in mt7925_tx_check_aggr

[Quan Zhou]

Previously, the AMPDU state bit for a given TID was set before attempting
to start a BA session, which could result in the AMPDU state being marked
active even if ieee80211_start_tx_ba_session() failed. This patch changes
the logic to only set the AMPDU state bit after successfully starting a BA
session, ensuring proper synchronization between AMPDU state and BA session
status.

This fixes potential issues with aggregation state tracking and improves
compatibility with mac80211 BA session management.

Fixes: 44eb173bdd4f ("wifi: mt76: mt7925: add link handling in mt7925_txwi_free")
Cc: stable at vger.kernel.org

Signed-off-by: Quan Zhou <quan.zhou at mediatek.com>
---
v2: modify to avoid weakening atomicity
---
 drivers/net/wireless/mediatek/mt76/mt7925/mac.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mac.c b/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
index 871b67101976..5e5b1df78633 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
@@ -881,8 +881,10 @@ static void mt7925_tx_check_aggr(struct ieee80211_sta *sta, struct sk_buff *skb,
 	else
 		mlink = &msta->deflink;
 
-	if (!test_and_set_bit(tid, &mlink->wcid.ampdu_state))
-		ieee80211_start_tx_ba_session(sta, tid, 0);
+	if (!test_and_set_bit(tid, &mlink->wcid.ampdu_state)) {
+		if (ieee80211_start_tx_ba_session(sta, tid, 0))
+			clear_bit(tid, &mlink->wcid.ampdu_state);
+	}
 }
 
 static bool
-- 
2.45.2