[PATCH mt76-next 17/27] wifi: mt76: mt7996: keep 4-address and decap state per station

[Felix Fietkau <nbd@nbd.name>]

mac80211 reports 4-address mode and decap offload once per station,
through sta_set_4addr and sta_set_decap_offload. mt7996_sta_set_4addr()
and mt7996_sta_set_decap_offload() set MT_WCID_FLAG_4ADDR and
MT_WCID_FLAG_HDR_TRANS only on the links that exist at that moment, but
the hardware keeps header translation per link. A link that is added
later starts without the flags, and a link that is removed at that time
keeps its old flags when it comes back, so the firmware gets the wrong
to_ds/from_ds pair for that link.

Keep both states in the station, and apply them to a link when the
callbacks run, when the link is set up and when it comes back.

Fixes: f520eceacd24 ("wifi: mt76: mt7996: Add mt7996_mac_sta_change_links callback")
Fixes: e8c819df0243 ("wifi: mt76: mt7996: Destroy active sta links in mt7996_mac_sta_remove()")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 .../net/wireless/mediatek/mt76/mt7996/main.c  | 29 +++++++++++--------
 .../wireless/mediatek/mt76/mt7996/mt7996.h    |  2 ++
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/main.c b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
index d868e9641334..bba5a8c6dec8 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
@@ -1155,6 +1155,16 @@ mt7996_sta_deflink_set(struct ieee80211_sta *sta, unsigned int link_id,
 	mt7996_sta_init_txq_wcid(sta, idx);
 }
 
+static void
+mt7996_sta_link_hdr_trans_set(struct mt7996_sta *msta,
+			      struct mt7996_sta_link *msta_link)
+{
+	assign_bit(MT_WCID_FLAG_4ADDR, &msta_link->wcid.flags,
+		   test_bit(MT_WCID_FLAG_4ADDR, &msta->wcid_flags));
+	assign_bit(MT_WCID_FLAG_HDR_TRANS, &msta_link->wcid.flags,
+		   test_bit(MT_WCID_FLAG_HDR_TRANS, &msta->wcid_flags));
+}
+
 static bool
 mt7996_sta_deflink_busy(struct mt7996_dev *dev, struct mt7996_sta *msta)
 {
@@ -1261,6 +1271,8 @@ mt7996_mac_sta_init_link(struct mt7996_dev *dev,
 	if (link_sta->sta->tdls)
 		set_bit(MT_WCID_FLAG_TDLS_PEER, &msta_link->wcid.flags);
 
+	mt7996_sta_link_hdr_trans_set(msta, msta_link);
+
 	ewma_avg_signal_init(&msta_link->avg_ack_signal);
 	ewma_signal_init(&msta_link->wcid.rssi);
 
@@ -1381,6 +1393,7 @@ mt7996_mac_sta_add_links(struct mt7996_dev *dev, struct ieee80211_vif *vif,
 		msta_link = mt76_dereference(msta->link[link_id], &dev->mt76);
 		if (msta_link) {
 			msta_link->wcid.link_valid = true;
+			mt7996_sta_link_hdr_trans_set(msta, msta_link);
 			if (msta->deflink_id == IEEE80211_LINK_UNSPECIFIED)
 				mt7996_sta_deflink_set(sta, link_id,
 						       msta_link->wcid.idx);
@@ -2166,6 +2179,7 @@ static void mt7996_sta_set_4addr(struct ieee80211_hw *hw,
 
 	mutex_lock(&dev->mt76.mutex);
 
+	assign_bit(MT_WCID_FLAG_4ADDR, &msta->wcid_flags, enabled);
 	for_each_sta_active_link(vif, sta, link_sta, link_id) {
 		struct mt7996_sta_link *msta_link;
 		struct mt7996_vif_link *link;
@@ -2178,11 +2192,7 @@ static void mt7996_sta_set_4addr(struct ieee80211_hw *hw,
 		if (!msta_link)
 			continue;
 
-		if (enabled)
-			set_bit(MT_WCID_FLAG_4ADDR, &msta_link->wcid.flags);
-		else
-			clear_bit(MT_WCID_FLAG_4ADDR, &msta_link->wcid.flags);
-
+		mt7996_sta_link_hdr_trans_set(msta, msta_link);
 		if (!msta_link->wcid.sta)
 			continue;
 
@@ -2212,6 +2222,7 @@ static void mt7996_sta_set_decap_offload(struct ieee80211_hw *hw,
 
 	mutex_lock(&dev->mt76.mutex);
 
+	assign_bit(MT_WCID_FLAG_HDR_TRANS, &msta->wcid_flags, enabled);
 	for_each_sta_active_link(vif, sta, link_sta, link_id) {
 		struct mt7996_sta_link *msta_link;
 		struct mt7996_vif_link *link;
@@ -2224,13 +2235,7 @@ static void mt7996_sta_set_decap_offload(struct ieee80211_hw *hw,
 		if (!msta_link)
 			continue;
 
-		if (enabled)
-			set_bit(MT_WCID_FLAG_HDR_TRANS,
-				&msta_link->wcid.flags);
-		else
-			clear_bit(MT_WCID_FLAG_HDR_TRANS,
-				  &msta_link->wcid.flags);
-
+		mt7996_sta_link_hdr_trans_set(msta, msta_link);
 		if (!msta_link->wcid.sta)
 			continue;
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
index 03fc0e7fd4f1..949e659b8e2d 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h
@@ -269,6 +269,8 @@ struct mt7996_sta {
 	u8 deflink_id;
 	u8 seclink_id;
 
+	unsigned long wcid_flags;
+
 	struct mt7996_vif *vif;
 };
 
-- 
2.47.3