e1000: remove races when changing mtu
this patch fixes a bug that occurs when routing packets and simultaneously
changing the mtu. the rx_buffer_len variable is used during the rx cleanup
and if that changes on the fly without stopping traffic bad things happen
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index cdbf4fb..2178e0d 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -3141,6 +3141,13 @@
break;
}
+ while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
+ msleep(1);
+ /* e1000_down has a dependency on max_frame_size */
+ hw->max_frame_size = max_frame;
+ if (netif_running(netdev))
+ e1000_down(adapter);
+
/* NOTE: netdev_alloc_skb reserves 16 bytes, and typically NET_IP_ALIGN
* means we reserve 2 more, this pushes us to allocate from the next
* larger slab size.
@@ -3169,11 +3176,16 @@
(max_frame == MAXIMUM_ETHERNET_VLAN_SIZE)))
adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE;
+ printk(KERN_INFO "e1000: %s changing MTU from %d to %d\n",
+ netdev->name, netdev->mtu, new_mtu);
netdev->mtu = new_mtu;
- hw->max_frame_size = max_frame;
if (netif_running(netdev))
- e1000_reinit_locked(adapter);
+ e1000_up(adapter);
+ else
+ e1000_reset(adapter);
+
+ clear_bit(__E1000_RESETTING, &adapter->flags);
return 0;
}