[PATCH net-next v2] net: mvneta: add support for hardware timestamps

[Russell King <rmk+kernel@armlinux.org.uk>]

Add support for hardware timestamps in (e.g.) the PHY by calling
skb_tx_timestamp() as close as reasonably possible to the point that
the hardware is instructed to send the queued packets.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
v2: add ethtool_op_get_ts_info(), remove FIXME from comment.

 drivers/net/ethernet/marvell/mvneta.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 476e73e502fe..01eedc3e54d9 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2985,6 +2985,13 @@ static netdev_tx_t mvneta_tx(struct sk_buff *skb, struct net_device *dev)
 		if (txq->count >= txq->tx_stop_threshold)
 			netif_tx_stop_queue(nq);
 
+		/* This is not really the true transmit point, since we batch
+		 * up several before hitting the hardware, but is the best we
+		 * can do without more complexity to walk the packets in the
+		 * pending section of the transmit queue.
+		 */
+		skb_tx_timestamp(skb);
+
 		if (!netdev_xmit_more() || netif_xmit_stopped(nq) ||
 		    txq->pending + frags > MVNETA_TXQ_DEC_SENT_MASK)
 			mvneta_txq_pend_desc_add(pp, txq, frags);
@@ -5357,6 +5364,7 @@ static const struct ethtool_ops mvneta_eth_tool_ops = {
 	.set_link_ksettings = mvneta_ethtool_set_link_ksettings,
 	.get_wol        = mvneta_ethtool_get_wol,
 	.set_wol        = mvneta_ethtool_set_wol,
+	.get_ts_info	= ethtool_op_get_ts_info,
 	.get_eee	= mvneta_ethtool_get_eee,
 	.set_eee	= mvneta_ethtool_set_eee,
 };
-- 
2.47.3