em(4): Don't write ITR, if the NIC is not running yet.

diff --git a/sys/dev/netif/em/if_em.c b/sys/dev/netif/em/if_em.c
index 29f72ca..31bf443 100644 (file)
--- a/sys/dev/netif/em/if_em.c
+++ b/sys/dev/netif/em/if_em.c
@@ -3983,7 +3983,9 @@ em_sysctl_int_throttle(SYSCTL_HANDLER_ARGS)
                adapter->int_throttle_ceil = 1000000000 / 256 / throttle;
        else
                adapter->int_throttle_ceil = 0;
-       E1000_WRITE_REG(&adapter->hw, E1000_ITR, throttle);
+
+       if (ifp->if_flags & IFF_RUNNING)
+               E1000_WRITE_REG(&adapter->hw, E1000_ITR, throttle);
 
        lwkt_serialize_exit(ifp->if_serializer);