[PATCH 6.6 266/283] net: mscc: ocelot: extract ocelot_xmit_timestamp() helper

Sasha Levin
2026-02-28T18:10:52Z

From: Ziyi Guo <n7l8m4@u.northwestern.edu>

[ Upstream commit 29372f07f7969a2f0490793226ecf6c8c6bde0fa ]

Extract the PTP timestamp handling logic from ocelot_port_xmit() into a
separate ocelot_xmit_timestamp() helper function. This is a pure
refactor with no behavioral change.

The helper returns false if the skb was consumed (freed) due to a
timestamp request failure, and true if the caller should continue with
frame injection. The rew_op value is returned via pointer.

This prepares for splitting ocelot_port_xmit() into separate FDMA and
register injection paths in a subsequent patch.

Signed-off-by: Ziyi Guo <n7l8m4@u.northwestern.edu>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20260208225602.1339325-2-n7l8m4@u.northwestern.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 026f6513c588 ("net: mscc: ocelot: add missing lock protection in ocelot_port_xmit_inj()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mscc/ocelot_net.c | 36 ++++++++++++++++----------
1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 21a87a3fc5562..e2b475bf58e6c 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -551,33 +551,41 @@ static int ocelot_port_stop(struct net_device *dev)
return 0;
}

-static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
+static bool ocelot_xmit_timestamp(struct ocelot *ocelot, int port,
+ struct sk_buff *skb, u32 *rew_op)
{
- struct ocelot_port_private *priv = netdev_priv(dev);
- struct ocelot_port *ocelot_port = &priv->port;
- struct ocelot *ocelot = ocelot_port->ocelot;
- int port = priv->port.index;
- u32 rew_op = 0;
-
- if (!static_branch_unlikely(&ocelot_fdma_enabled) &&
- !ocelot_can_inject(ocelot, 0))
- return NETDEV_TX_BUSY;
-
- /* Check if timestamping is needed */
if (ocelot->ptp && (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
struct sk_buff *clone = NULL;

if (ocelot_port_txtstamp_request(ocelot, port, skb, &clone)) {
kfree_skb(skb);
- return NETDEV_TX_OK;
+ return false;
}

if (clone)
OCELOT_SKB_CB(skb)->clone = clone;

- rew_op = ocelot_ptp_rew_op(skb);
+ *rew_op = ocelot_ptp_rew_op(skb);
}

+ return true;
+}
+
+static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ocelot_port_private *priv = netdev_priv(dev);
+ struct ocelot_port *ocelot_port = &priv->port;
+ struct ocelot *ocelot = ocelot_port->ocelot;
+ int port = priv->port.index;
+ u32 rew_op = 0;
+
+ if (!static_branch_unlikely(&ocelot_fdma_enabled) &&
+ !ocelot_can_inject(ocelot, 0))
+ return NETDEV_TX_BUSY;
+
+ if (!ocelot_xmit_timestamp(ocelot, port, skb, &rew_op))
+ return NETDEV_TX_OK;
+
if (static_branch_unlikely(&ocelot_fdma_enabled)) {
ocelot_fdma_inject_frame(ocelot, port, rew_op, skb, dev);
} else {
--
2.51.0