net: txq_trans_update() helper

We would like to get rid of netdev->trans_start = jiffies; that about all net
drivers have to use in their start_xmit() function, and use txq->trans_start
instead.

This can be done generically in core network, as suggested by David.

Some devices, (particularly loopback) dont need trans_start update, because
they dont have transmit watchdog. We could add a new device flag, or rely
on fact that txq->tran_start can be updated is txq->xmit_lock_owner is
different than -1. Use a helper function to hide our choice.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 67b4f3e3d4a..7ab31a7576a 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -302,8 +302,11 @@ static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
                 for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
                      tries > 0; --tries) {
                         if (__netif_tx_trylock(txq)) {
-                                if (!netif_tx_queue_stopped(txq))
+                                if (!netif_tx_queue_stopped(txq)) {
                                         status = ops->ndo_start_xmit(skb, dev);
+                                        if (status == NETDEV_TX_OK)
+                                                txq_trans_update(txq);
+                                }
                                 __netif_tx_unlock(txq);
 
                                 if (status == NETDEV_TX_OK)