Commit a264b981 authored Jul 30, 2013 by Uwe Kleine-König Committed by David S. Miller Jul 30, 2013

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



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>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a0db856a

drivers/net/ethernet/freescale/fec_main.c

+0 −5

Original line number	Diff line number	Diff line
		@@ -294,11 +294,6 @@ 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;