1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index bf57b3cb16ab..0bc00991d310 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -779,6 +779,7 @@ efx_realloc_channels(struct efx_nic *efx, u32 rxq_entries, u32 txq_entries)
                                                 tx_queue->txd.entries);
         }
 
+        efx_device_detach_sync(efx);
         efx_stop_all(efx);
         efx_stop_interrupts(efx, true);
 
@@ -832,6 +833,7 @@ out:
 
         efx_start_interrupts(efx, true);
         efx_start_all(efx);
+        netif_device_attach(efx->net_dev);
         return rc;
 
 rollback:
@@ -1641,8 +1643,12 @@ static void efx_stop_all(struct efx_nic *efx)
         /* Flush efx_mac_work(), refill_workqueue, monitor_work */
         efx_flush_all(efx);
 
-        /* Stop the kernel transmit interface late, so the watchdog
-         * timer isn't ticking over the flush */
+        /* Stop the kernel transmit interface.  This is only valid if
+         * the device is stopped or detached; otherwise the watchdog
+         * may fire immediately.
+         */
+        WARN_ON(netif_running(efx->net_dev) &&
+                netif_device_present(efx->net_dev));
         netif_tx_disable(efx->net_dev);
 
         efx_stop_datapath(efx);
@@ -1963,16 +1969,18 @@ static int efx_change_mtu(struct net_device *net_dev, int new_mtu)
         if (new_mtu > EFX_MAX_MTU)
                 return -EINVAL;
 
-        efx_stop_all(efx);
-
         netif_dbg(efx, drv, efx->net_dev, "changing MTU to %d\n", new_mtu);
 
+        efx_device_detach_sync(efx);
+        efx_stop_all(efx);
+
         mutex_lock(&efx->mac_lock);
         net_dev->mtu = new_mtu;
         efx->type->reconfigure_mac(efx);
         mutex_unlock(&efx->mac_lock);
 
         efx_start_all(efx);
+        netif_device_attach(efx->net_dev);
         return 0;
 }