dpaa_eth: copy timestamp fields to new skb in A-050385 workaround

The timestamp fields should be copied to new skb too in
A-050385 workaround for later TX timestamping handling.

Fixes: 3c68b8ff ("dpaa_eth: FMan erratum A050385 workaround")
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Camelia Groza <camelia.groza@nxp.com>
Link: https://lore.kernel.org/r/20201201075258.1875-1-yangbo.lu@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/dpaa/dpaa_eth.c

@@ -2120,6 +2120,15 @@ static int dpaa_a050385_wa(struct net_device *net_dev, struct sk_buff **s)
 	skb_copy_header(new_skb, skb);
 	new_skb->dev = skb->dev;
 
+	/* Copy relevant timestamp info from the old skb to the new */
+	if (priv->tx_tstamp) {
+		skb_shinfo(new_skb)->tx_flags = skb_shinfo(skb)->tx_flags;
+		skb_shinfo(new_skb)->hwtstamps = skb_shinfo(skb)->hwtstamps;
+		skb_shinfo(new_skb)->tskey = skb_shinfo(skb)->tskey;
+		if (skb->sk)
+			skb_set_owner_w(new_skb, skb->sk);
+	}
+
 	/* We move the headroom when we align it so we have to reset the
 	 * network and transport header offsets relative to the new data
 	 * pointer. The checksum offload relies on these offsets.
@@ -2127,7 +2136,6 @@ static int dpaa_a050385_wa(struct net_device *net_dev, struct sk_buff **s)
 	skb_set_network_header(new_skb, skb_network_offset(skb));
 	skb_set_transport_header(new_skb, skb_transport_offset(skb));
 
-	/* TODO: does timestamping need the result in the old skb? */
 	dev_kfree_skb(skb);
 	*s = new_skb;