[PATCH v1] net: stmmac: Modify the judgment condition of "tx_avail" from 1 to 2

[2694439648 at qq.com]

From: "hailong.fan" <hailong.fan at siengine.com>

    Under certain conditions, a WARN_ON will be triggered
    if avail equals 1.

    For example, when a VLAN packet is to send,
    stmmac_vlan_insert consumes one unit of space,
    and the data itself consumes another.
    actually requiring 2 units of space in total.

    ---
    V0-V1:
       1. Stop their queues earlier

Signed-off-by: hailong.fan <hailong.fan at siengine.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 7b90ecd3a..738a0c94d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4529,7 +4529,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 		}
 	}
 
-	if (unlikely(stmmac_tx_avail(priv, queue) < nfrags + 1)) {
+	if (unlikely(stmmac_tx_avail(priv, queue) < nfrags + 2)) {
 		if (!netif_tx_queue_stopped(netdev_get_tx_queue(dev, queue))) {
 			netif_tx_stop_queue(netdev_get_tx_queue(priv->dev,
 								queue));
@@ -4675,7 +4675,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 		print_pkt(skb->data, skb->len);
 	}
 
-	if (unlikely(stmmac_tx_avail(priv, queue) <= (MAX_SKB_FRAGS + 1))) {
+	if (unlikely(stmmac_tx_avail(priv, queue) <= (MAX_SKB_FRAGS + 2))) {
 		netif_dbg(priv, hw, priv->dev, "%s: stop transmitted packets\n",
 			  __func__);
 		netif_tx_stop_queue(netdev_get_tx_queue(priv->dev, queue));
-- 
2.34.1