[PATCH v1 2/2] wifi: mt76: free a partial rx A-MSDU when the phy is unregistered

[Eason Lai <eason.lai@mediatek.com>]

mt76_rx_release_burst() keeps the first subframes of an A-MSDU in
phy->rx_amsdu[q] until the last subframe arrives. If the phy or device
is unregistered in the meantime, nothing frees this skb and it leaks.

Free any parked A-MSDU after ieee80211_unregister_hw(), once rx has
stopped.

Fixes: cc4b3c139ad3 ("mt76: mt7915: enable hw rx-amsdu de-aggregation")
Signed-off-by: Eason Lai <eason.lai@mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mac80211.c | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c
index 19a2e8a26c3e..fb8494ad8f8d 100644
--- a/drivers/net/wireless/mediatek/mt76/mac80211.c
+++ b/drivers/net/wireless/mediatek/mt76/mac80211.c
@@ -603,6 +603,19 @@ int mt76_register_phy(struct mt76_phy *phy, bool vht,
 }
 EXPORT_SYMBOL_GPL(mt76_register_phy);
 
+static void mt76_rx_amsdu_purge(struct mt76_phy *phy)
+{
+	int q;
+
+	for (q = 0; q < ARRAY_SIZE(phy->rx_amsdu); q++) {
+		spin_lock_bh(&phy->rx_amsdu[q].lock);
+		dev_kfree_skb(phy->rx_amsdu[q].head);
+		phy->rx_amsdu[q].head = NULL;
+		phy->rx_amsdu[q].tail = NULL;
+		spin_unlock_bh(&phy->rx_amsdu[q].lock);
+	}
+}
+
 void mt76_unregister_phy(struct mt76_phy *phy)
 {
 	struct mt76_dev *dev = phy->dev;
@@ -614,6 +627,7 @@ void mt76_unregister_phy(struct mt76_phy *phy)
 		mt76_led_cleanup(phy);
 	mt76_tx_status_check(dev, true);
 	ieee80211_unregister_hw(phy->hw);
+	mt76_rx_amsdu_purge(phy);
 	dev->phys[phy->band_idx] = NULL;
 }
 EXPORT_SYMBOL_GPL(mt76_unregister_phy);
@@ -811,6 +825,7 @@ EXPORT_SYMBOL_GPL(mt76_register_device);
 void mt76_unregister_device(struct mt76_dev *dev)
 {
 	struct ieee80211_hw *hw = dev->hw;
+	int i;
 
 	if (!test_bit(MT76_STATE_REGISTERED, &dev->phy.state))
 		return;
@@ -820,6 +835,13 @@ void mt76_unregister_device(struct mt76_dev *dev)
 	mt76_tx_status_check(dev, true);
 	mt76_wcid_cleanup(dev, &dev->global_wcid);
 	ieee80211_unregister_hw(hw);
+
+	/* radio phys sharing dev->hw (e.g. mt7996) are not unregistered
+	 * separately
+	 */
+	for (i = 0; i < ARRAY_SIZE(dev->phys); i++)
+		if (dev->phys[i])
+			mt76_rx_amsdu_purge(dev->phys[i]);
 }
 EXPORT_SYMBOL_GPL(mt76_unregister_device);
 
-- 
2.45.2