[PATCH 2/3] net: arc_emac: reset txbd_curr and txbd_dirty pointers to zero

[Alexander Kochetkov]

EMAC reset internal tx ring pointer to zero at statup.
txbd_curr and txbd_dirty can be different from zero.
That cause ethernet transfer hang (no packets transmitted).

In order to reproduce, run on device:
    ifconfig eth0 down
    ifconfig eth0 up

Signed-off-by: Alexander Kochetkov <al.kochet@xxxxxxxxx>

---
CC: stable@xxxxxxxxxxxxxxx # 3.18.x-
---
 drivers/net/ethernet/arc/emac_main.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c
index 63a63e3..4f6e5be 100644
--- a/drivers/net/ethernet/arc/emac_main.c
+++ b/drivers/net/ethernet/arc/emac_main.c
@@ -447,6 +447,9 @@ static int arc_emac_open(struct net_device *ndev)
 		*last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;
 	}
 
+	priv->txbd_curr = 0;
+	priv->txbd_dirty = 0;
+
 	/* Clean Tx BD's */
 	memset(priv->txbd, 0, TX_RING_SZ);
 
-- 
1.7.9.5