[PATCH] net/fec: Don't let ndo_start_xmit return NETDEV_TX_BUSY without link

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Don't test for having link and let hardware deal with this situation.

Without this patch I see a machine running an -rt patched Linux being
stuck in sch_direct_xmit when it looses link while there is still a
packet to be sent. In this case the fec_enet_start_xmit routine returned
NETDEV_TX_BUSY which makes the network stack reschedule the packet and
so sch_direct_xmit calls fec_enet_start_xmit again.
I failed to reproduce a complete hang without -rt, but I think the
problem exists there, too.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Hello,

this is a new variant of "[PATCH] net/fec: call netif_carrier_off when
not having link" that drops calling netif_carrier_{on,off} in
fec_restart because the phy library already handles that.

I think this is 3.11 material assuming you are ok with the patch now.

Best regards
Uwe

 drivers/net/ethernet/freescale/fec_main.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index ed61160..792d729 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -280,11 +280,6 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	unsigned short	status;
 	unsigned int index;
 
-	if (!fep->link) {
-		/* Link is down or auto-negotiation is in progress. */
-		return NETDEV_TX_BUSY;
-	}
-
 	/* Fill in a Tx ring entry */
 	bdp = fep->cur_tx;
 
-- 
1.8.3.2