mt76: fix tx status reporting for non-probing frames

On MT76x2, the hardware does not report tx status in the FIFO register,
if the packet id is 0.
Change the allocation of packet IDs to use 0 for no-ack packets, 1 for
non-probing packets and 2-255 for packets with tx status requested.
Fixes rate control issues
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -239,7 +239,9 @@ struct mt76_rx_tid {
 #define MT_TX_CB_TXS_FAILED		BIT(2)
 
 #define MT_PACKET_ID_MASK		GENMASK(7, 0)
-#define MT_PACKET_ID_NO_ACK		MT_PACKET_ID_MASK
+#define MT_PACKET_ID_NO_ACK		0
+#define MT_PACKET_ID_NO_SKB		1
+#define MT_PACKET_ID_FIRST		2
 
 #define MT_TX_STATUS_SKB_TIMEOUT	HZ
 

drivers/net/wireless/mediatek/mt76/mt76x02_mac.c

@@ -433,7 +433,7 @@ void mt76x02_send_tx_status(struct mt76x02_dev *dev,
 	}
 
 	if (wcid) {
-		if (stat->pktid)
+		if (stat->pktid >= MT_PACKET_ID_FIRST)
 			status.skb = mt76_tx_status_skb_get(mdev, wcid,
 							    stat->pktid, &list);
 		if (status.skb)

drivers/net/wireless/mediatek/mt76/mt76x02_txrx.c

@@ -177,7 +177,7 @@ int mt76x02_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr,
 	if (ret < 0)
 		return ret;
 
-	if (pid && pid != MT_PACKET_ID_NO_ACK)
+	if (pid >= MT_PACKET_ID_FIRST)
 		qsel = MT_QSEL_MGMT;
 
 	*tx_info = FIELD_PREP(MT_TXD_INFO_QSEL, qsel) |

drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c

@@ -87,8 +87,7 @@ int mt76x02u_tx_prepare_skb(struct mt76_dev *mdev, void *data,
 	pid = mt76_tx_status_skb_add(mdev, wcid, skb);
 	txwi->pktid = pid;
 
-	if ((pid && pid != MT_PACKET_ID_NO_ACK) ||
-	    q2ep(q->hw_idx) == MT_EP_OUT_HCCA)
+	if (pid >= MT_PACKET_ID_FIRST || q2ep(q->hw_idx) == MT_EP_OUT_HCCA)
 		qsel = MT_QSEL_MGMT;
 	else
 		qsel = MT_QSEL_EDCA;

drivers/net/wireless/mediatek/mt76/tx.c

@@ -170,21 +170,22 @@ mt76_tx_status_skb_add(struct mt76_dev *dev, struct mt76_wcid *wcid,
 	int pid;
 
 	if (!wcid)
-		return 0;
+		return MT_PACKET_ID_NO_ACK;
 
 	if (info->flags & IEEE80211_TX_CTL_NO_ACK)
 		return MT_PACKET_ID_NO_ACK;
 
 	if (!(info->flags & (IEEE80211_TX_CTL_REQ_TX_STATUS |
 			     IEEE80211_TX_CTL_RATE_CTRL_PROBE)))
-		return 0;
+		return MT_PACKET_ID_NO_SKB;
 
 	spin_lock_bh(&dev->status_list.lock);
 
 	memset(cb, 0, sizeof(*cb));
 	wcid->packet_id = (wcid->packet_id + 1) & MT_PACKET_ID_MASK;
-	if (!wcid->packet_id || wcid->packet_id == MT_PACKET_ID_NO_ACK)
-		wcid->packet_id = 1;
+	if (wcid->packet_id == MT_PACKET_ID_NO_ACK ||
+	    wcid->packet_id == MT_PACKET_ID_NO_SKB)
+		wcid->packet_id = MT_PACKET_ID_FIRST;
 
 	pid = wcid->packet_id;
 	cb->wcid = wcid->idx;