From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Tue, 8 Jul 2014 11:40:38 +0000 (+0100)
Subject: net: fec: quiesce packet processing when taking link down in fec_enet_adjust_link()
X-Git-Tag: pci-v3.17-changes-2~59^2~202^2~1
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f208ce10046888052d3a5e9fc88b7c1b819877d2;p=users%2Fdwmw2%2Flinux.git

net: fec: quiesce packet processing when taking link down in fec_enet_adjust_link()

When the link goes down, the adjust_link method will be called, but
there is no synchronisation to ensure that we won't be processing some
last remaining packets via the NAPI handlers while performing a reset of
the device.

Add the necessary synchronisation to ensure that packet processing
is complete before we stop and reset the FEC.

Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 124d3c5f80464..0186fec1f7f9d 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1530,7 +1530,11 @@ static void fec_enet_adjust_link(struct net_device *ndev)
 		}
 	} else {
 		if (fep->link) {
+			napi_disable(&fep->napi);
+			netif_tx_lock_bh(ndev);
 			fec_stop(ndev);
+			netif_tx_unlock_bh(ndev);
+			napi_enable(&fep->napi);
 			fep->link = phy_dev->link;
 			status_change = 1;
 		}