Add padding for small tx packets

target/linux/generic/pending-5.15/739-add-software-padding-ethernet-tx-path.patch

@@ -0,0 +1,18 @@
+diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+index 31968b8..d93d7fa 100644
+--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
++++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+@@ -1523,6 +1523,13 @@ static int mtk_tx_map(struct sk_buff *skb, struct net_device *dev,
+ 	int queue = skb_get_queue_mapping(skb);
+ 	int k = 0;
+
++	if (skb->len <= 40) {
++		if (skb_put_padto(skb, 60))
++			return -ENOMEM;
++		txd_info.size = skb_headlen(skb);
++		txd_info.last = !skb_is_nonlinear(skb);
++	}
++
+ 	txq = netdev_get_tx_queue(dev, queue);
+ 	itxd = ring->next_free;
+ 	itxd_pdma = qdma_to_pdma(ring, itxd);