NET: fec: only enable napi if we are successful

If napi is left enabled after a failed attempt to bring the interface
up, we BUG:

fec 2188000.ethernet eth0: no PHY, assuming direct connection to switch
libphy: PHY fixed-0:00 not found
fec 2188000.ethernet eth0: could not attach to PHY
------------[ cut here ]------------
kernel BUG at include/linux/netdevice.h:502!
Internal error: Oops - BUG: 0 [#1] SMP ARM
...
PC is at fec_enet_open+0x4d0/0x500
LR is at __dev_open+0xa4/0xfc

Only enable napi after we are past all the failure paths.

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

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index e3ffd7aee02f..f49f43fef2aa 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2079,8 +2079,6 @@ fec_enet_open(struct net_device *ndev)
 
         fec_enet_clk_enable(ndev, true);
 
-        napi_enable(&fep->napi);
-
         /* I should reset the ring buffers here, but I don't yet know
          * a simple way to do that.
          */
@@ -2096,6 +2094,7 @@ fec_enet_open(struct net_device *ndev)
                 return ret;
         }
 
+        napi_enable(&fep->napi);
         phy_start(fep->phy_dev);
         netif_tx_start_all_queues(ndev);
         fep->opened = 1;