Commit b5ca88eb authored Jul 08, 2008 by Jesse Brandeburg Committed by Jeff Garzik Jul 11, 2008

ixgb: fix race on rx_buffer_len in mtu change



some random coverage testing found that when changing mtu
under heavy traffic load, NAPI would use the rx_buffer_len variable
after it had been changed by change_mtu.

Similar to e1000 bugs found long ago.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

parent 34336635

drivers/net/ixgb/ixgb_main.c

+7 −3

Original line number	Diff line number	Diff line
		@@ -1573,14 +1573,18 @@ ixgb_change_mtu(struct net_device *netdev, int new_mtu)
		return -EINVAL;
		}

		if (old_max_frame == max_frame)
		return 0;

		if (netif_running(netdev))
		ixgb_down(adapter, true);

		adapter->rx_buffer_len = max_frame + 8; /* + 8 for errata */

		netdev->mtu = new_mtu;

		if ((old_max_frame != max_frame) && netif_running(netdev)) {
		ixgb_down(adapter, true);
		if (netif_running(netdev))
		ixgb_up(adapter);
		}

		return 0;
		}

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