e1000e: flow control thresholds not correct when changing mtu

When changing MTU, save it off prior to resetting otherwise the flow control
thresholds may be miscalculated.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index 63458270ce1b..fad8f9ea0043 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -4305,8 +4305,10 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
 
         while (test_and_set_bit(__E1000_RESETTING, &adapter->state))
                 msleep(1);
-        /* e1000e_down has a dependency on max_frame_size */
+        /* e1000e_down -> e1000e_reset dependent on max_frame_size & mtu */
         adapter->max_frame_size = max_frame;
+        e_info("changing MTU from %d to %d\n", netdev->mtu, new_mtu);
+        netdev->mtu = new_mtu;
         if (netif_running(netdev))
                 e1000e_down(adapter);
 
@@ -4336,9 +4338,6 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
                 adapter->rx_buffer_len = ETH_FRAME_LEN + VLAN_HLEN
                                          + ETH_FCS_LEN;
 
-        e_info("changing MTU from %d to %d\n", netdev->mtu, new_mtu);
-        netdev->mtu = new_mtu;
-
         if (netif_running(netdev))
                 e1000e_up(adapter);
         else