[PATCH mt76-next 09/27] wifi: mt76: mt7996: report station statistics from the primary link

[Felix Fietkau <nbd@nbd.name>]

mt7996_sta_statistics() and mt7996_ethtool_worker() read the TX rate,
the TX counters and the ACK signal from msta->deflink. That is the
msta_link of the first link of the station, not of its primary link.
When the first link of an MLD station is removed, msta->deflink keeps
the values of the removed link, and the station reports them until it
is removed.

Read them from the link that deflink_id selects.

msta->deflink also holds the RX reorder state, the TX aggregation
state and the def_wcid target of all links. These are state of the
whole station, and wcid_to_sta() needs def_wcid at the start of
drv_priv, so they stay there.

Fixes: f520eceacd24 ("wifi: mt76: mt7996: Add mt7996_mac_sta_change_links callback")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 .../net/wireless/mediatek/mt76/mt7996/main.c  | 20 ++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/main.c b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
index f94b5fdfca24..f44af31281b7 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
@@ -1920,9 +1920,16 @@ static void mt7996_sta_statistics(struct ieee80211_hw *hw,
 {
 	struct mt7996_dev *dev = mt7996_hw_dev(hw);
 	struct mt7996_sta *msta = (struct mt7996_sta *)sta->drv_priv;
-	struct mt7996_sta_link *msta_link = &msta->deflink;
-	struct rate_info *txrate = &msta_link->wcid.rate;
+	struct mt7996_sta_link *msta_link;
+	struct rate_info *txrate;
 
+	rcu_read_lock();
+
+	msta_link = mt7996_sta_link(msta, msta->deflink_id);
+	if (!msta_link)
+		goto out;
+
+	txrate = &msta_link->wcid.rate;
 	if (txrate->legacy || txrate->flags) {
 		if (txrate->legacy) {
 			sinfo->txrate.legacy = txrate->legacy;
@@ -1965,6 +1972,9 @@ static void mt7996_sta_statistics(struct ieee80211_hw *hw,
 		sinfo->rx_packets = msta_link->wcid.stats.rx_packets;
 		sinfo->filled |= BIT_ULL(NL80211_STA_INFO_RX_PACKETS);
 	}
+
+out:
+	rcu_read_unlock();
 }
 
 static void mt7996_link_rate_ctrl_update(void *data,
@@ -2264,11 +2274,15 @@ static void mt7996_ethtool_worker(void *wi_data, struct ieee80211_sta *sta)
 {
 	struct mt76_ethtool_worker_info *wi = wi_data;
 	struct mt7996_sta *msta = (struct mt7996_sta *)sta->drv_priv;
-	struct mt7996_sta_link *msta_link = &msta->deflink;
+	struct mt7996_sta_link *msta_link;
 
 	if (msta->vif->deflink.mt76.idx != wi->idx)
 		return;
 
+	msta_link = mt7996_sta_link(msta, msta->deflink_id);
+	if (!msta_link)
+		return;
+
 	mt76_ethtool_worker(wi, &msta_link->wcid.stats, true);
 }
 
-- 
2.47.3