bge(4) patch to allow but disable by-default, TSO4

--- sys/dev/bge/if_bge.c.orig   2013-05-12 08:52:43.000000000 -0700
+++ sys/dev/bge/if_bge.c        2013-05-12 08:52:27.000000000 -0700
@@ -3697,7 +3697,11 @@ bge_attach(device_t dev)
        ifp->if_capabilities = IFCAP_HWCSUM | IFCAP_VLAN_HWTAGGING |
            IFCAP_VLAN_MTU;
        if ((sc->bge_flags & (BGE_FLAG_TSO | BGE_FLAG_TSO3)) != 0) {
-               ifp->if_hwassist |= CSUM_TSO;
+               /* BCM57{17,19} showing resets in the lab with TSO enabled.
+                * Disabling CSUM_TSO by-default for this hardware until
+                * testing can prove stable with segment offload enabled. */
+               if (!BGE_IS_5717_PLUS(sc))
+                       ifp->if_hwassist |= CSUM_TSO;
                ifp->if_capabilities |= IFCAP_TSO4 | IFCAP_VLAN_HWTSO;
        }
 #ifdef IFCAP_VLAN_HWCSUM