Shuyu Wei <wsy2220 at gmail.com> : [...] > diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c > index a3a9392..c2447b0 100644 > --- a/drivers/net/ethernet/arc/emac_main.c > +++ b/drivers/net/ethernet/arc/emac_main.c > @@ -686,6 +686,9 @@ static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev) > > skb_tx_timestamp(skb); > > + /* Make sure timestamp is set */ > + smp_wmb(); Should be dma_wmb() (see davem's message). It's completely unrelated to SMP. -- Ueimor