[PATCH net] net: lan78xx: advertise tx software timestamping support

[Markus Bloechl]

lan78xx already calls skb_tx_timestamp() in its lan78xx_start_xmit().
Override .get_ts_info to also advertise this capability
(SOF_TIMESTAMPING_TX_SOFTWARE) via ethtool.

Signed-off-by: Markus Blöchl <markus.bloechl@xxxxxxxxxxxxx>
---

Notes:
	The main motivation for this patch was that e.g. linuxptp refuses
	to start if the driver lacks support for the required timestamping
	features.

	I also recognized that many usb ethernet drivers which use the usbnet
	infrastructure do not override .get_ts_info accordingly, despite calling
	skb_tx_timestamp() indirectly in their .ndo_start_xmit handler
	via usbnet_start_xmit().
	For most of them the .get_ts_info override from usbnet is lost when
	they override .ethtool_ops again.
	Should they all receive a similar patch?

 drivers/net/usb/lan78xx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 6acc5e904518..02bce40a67e5 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -1645,6 +1645,7 @@ static const struct ethtool_ops lan78xx_ethtool_ops = {
 	.get_strings	= lan78xx_get_strings,
 	.get_wol	= lan78xx_get_wol,
 	.set_wol	= lan78xx_set_wol,
+	.get_ts_info	= ethtool_op_get_ts_info,
 	.get_eee	= lan78xx_get_eee,
 	.set_eee	= lan78xx_set_eee,
 	.get_pauseparam	= lan78xx_get_pause,

base-commit: a6f8ee58a8e35f7e4380a5efce312e2a5bc27497