[PATCH net-next 5/9] sunvnet: add memory barrier before check for tx enable

[Shannon Nelson]

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.nel...@oracle.com>
---
 drivers/net/ethernet/sun/sunvnet_common.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/net/ethernet/sun/sunvnet_common.c 
b/drivers/net/ethernet/sun/sunvnet_common.c
index 5d0d386..98e758e 100644
--- a/drivers/net/ethernet/sun/sunvnet_common.c
+++ b/drivers/net/ethernet/sun/sunvnet_common.c
@@ -1467,6 +1467,7 @@ ldc_start_done:
        dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
        if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
                netif_tx_stop_queue(txq);
+               dma_wmb();
                if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
                        netif_tx_wake_queue(txq);
        }
-- 
1.7.1