From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
	Jakub Kicinski <kuba@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12 0793/1102] net: stmmac: add stmmac_tso_header_size()
Date: Thu, 17 Sep 2026 16:12:16 +0100
Message-ID: <20260917151600.379961937@linuxfoundation.org>
In-Reply-To: <20260917151539.408551884@linuxfoundation.org>
References: <20260917151539.408551884@linuxfoundation.org>
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6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

[ Upstream commit f799b5dab9c98a4b52a93d1c357916e0f0b7e663 ]

We will need to compute the size of the protocol headers in two places,
so move this into a separate function.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1w7ptJ-0000000Eat5-2ZlA@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 5e38d732ec67 ("net: stmmac: fix TX descriptor availability check for TSO traffic")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 20 ++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 548e2be390d23..409d36c1960c3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4151,6 +4151,18 @@ static void stmmac_flush_tx_descriptors(struct stmmac_priv *priv, int queue)
 	stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, queue);
 }
 
+static size_t stmmac_tso_header_size(struct sk_buff *skb)
+{
+	size_t size;
+
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
+		size = skb_transport_offset(skb) + sizeof(struct udphdr);
+	else
+		size = skb_tcp_all_headers(skb);
+
+	return size;
+}
+
 /**
  *  stmmac_tso_xmit - Tx entry point of the driver for oversized frames (TSO)
  *  @skb : the socket buffer
@@ -4222,13 +4234,11 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
 	first_tx = tx_q->cur_tx;
 
 	/* Compute header lengths */
-	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
-		proto_hdr_len = skb_transport_offset(skb) + sizeof(struct udphdr);
+	proto_hdr_len = stmmac_tso_header_size(skb);
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
 		hdr = sizeof(struct udphdr);
-	} else {
-		proto_hdr_len = skb_tcp_all_headers(skb);
+	else
 		hdr = tcp_hdrlen(skb);
-	}
 
 	/* Desc availability based on threshold should be enough safe */
 	if (unlikely(stmmac_tx_avail(priv, queue) <
-- 
2.53.0