From 3854de7b38be742cf7558476956d12414cb274f2 Mon Sep 17 00:00:00 2001
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Tue, 21 Apr 2026 08:43:07 +0200
Subject: [PATCH] net: airoha: stop net_device TX queue before updating CPU
 index

Currently, airoha_eth driver updates the CPU index register prior of
verifying whether the number of free descriptors has fallen below the
threshold.
Move net_device TX queue length check before updating the TX CPU index
in order to update TX CPU index even if there are more packets to be
transmitted but the net_device TX queue is going to be stopped
accounting the inflight packets.

Fixes: 1d304174106c ("net: airoha: Implement BQL support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260421-airoha-xmit-stop-condition-v1-1-e670d6a48467@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -2094,17 +2094,16 @@ static netdev_tx_t airoha_dev_xmit(struc
 
 	skb_tx_timestamp(skb);
 	netdev_tx_sent_queue(txq, skb->len);
+	if (q->ndesc - q->queued < q->free_thr) {
+		netif_tx_stop_queue(txq);
+		q->txq_stopped = true;
+	}
 
 	if (netif_xmit_stopped(txq) || !netdev_xmit_more())
 		airoha_qdma_rmw(qdma, REG_TX_CPU_IDX(qid),
 				TX_RING_CPU_IDX_MASK,
 				FIELD_PREP(TX_RING_CPU_IDX_MASK, index));
 
-	if (q->ndesc - q->queued < q->free_thr) {
-		netif_tx_stop_queue(txq);
-		q->txq_stopped = true;
-	}
-
 	spin_unlock_bh(&q->lock);
 
 	return NETDEV_TX_OK;
