sunvnet: add memory barrier before check for tx enable

In order to allow the underlying LDC and outstanding memory operations
to potentially catch up with the driver's Tx requests, add a memory
barrier before checking again for available tx descriptors.

Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Shannon Nelson 2017-02-13 10:57:00 -08:00 committed by David S. Miller
parent f2f3e210bf
commit fd263fb6e7
1 changed files with 1 additions and 0 deletions

View File

@ -1427,6 +1427,7 @@ int sunvnet_start_xmit_common(struct sk_buff *skb, struct net_device *dev,
dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
netif_tx_stop_queue(txq);
smp_rmb();
if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
netif_tx_wake_queue(txq);
}