Index: head/sys/dev/e1000/if_em.h
===================================================================
--- head/sys/dev/e1000/if_em.h
+++ head/sys/dev/e1000/if_em.h
@@ -269,7 +269,7 @@
 #define HW_DEBUGOUT1(S, A)          if (DEBUG_HW) printf(S "\n", A)
 #define HW_DEBUGOUT2(S, A, B)       if (DEBUG_HW) printf(S "\n", A, B)
 
-#define EM_MAX_SCATTER		64
+#define EM_MAX_SCATTER		40
 #define EM_VFTA_SIZE		128
 #define EM_TSO_SIZE		(65535 + sizeof(struct ether_vlan_header))
 #define EM_TSO_SEG_SIZE		4096	/* Max dma segment size */
Index: head/sys/dev/e1000/if_em.c
===================================================================
--- head/sys/dev/e1000/if_em.c
+++ head/sys/dev/e1000/if_em.c
@@ -3193,9 +3193,11 @@
 	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
 	if_setioctlfn(ifp, em_ioctl);
 	if_setgetcounterfn(ifp, em_get_counter);
+
 	/* TSO parameters */
 	ifp->if_hw_tsomax = IP_MAXPACKET;
-	ifp->if_hw_tsomaxsegcount = EM_MAX_SCATTER;
+	/* Take m_pullup(9)'s in em_xmit() w/ TSO into acount. */
+	ifp->if_hw_tsomaxsegcount = EM_MAX_SCATTER - 5;
 	ifp->if_hw_tsomaxsegsize = EM_TSO_SEG_SIZE;
 
 #ifdef EM_MULTIQUEUE
Index: head/sys/dev/e1000/if_igb.h
===================================================================
--- head/sys/dev/e1000/if_igb.h
+++ head/sys/dev/e1000/if_igb.h
@@ -278,7 +278,7 @@
 #define HW_DEBUGOUT1(S, A)          if (DEBUG_HW) printf(S "\n", A)
 #define HW_DEBUGOUT2(S, A, B)       if (DEBUG_HW) printf(S "\n", A, B)
 
-#define IGB_MAX_SCATTER		64
+#define IGB_MAX_SCATTER		40
 #define IGB_VFTA_SIZE		128
 #define IGB_BR_SIZE		4096	/* ring buf size */
 #define IGB_TSO_SIZE		(65535 + sizeof(struct ether_vlan_header))
Index: head/sys/dev/e1000/if_igb.c
===================================================================
--- head/sys/dev/e1000/if_igb.c
+++ head/sys/dev/e1000/if_igb.c
@@ -3139,6 +3139,12 @@
 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
 	ifp->if_ioctl = igb_ioctl;
 	ifp->if_get_counter = igb_get_counter;
+
+	/* TSO parameters */
+	ifp->if_hw_tsomax = IP_MAXPACKET;
+	ifp->if_hw_tsomaxsegcount = IGB_MAX_SCATTER;
+	ifp->if_hw_tsomaxsegsize = IGB_TSO_SEG_SIZE;
+
 #ifndef IGB_LEGACY_TX
 	ifp->if_transmit = igb_mq_start;
 	ifp->if_qflush = igb_qflush;
Index: head/sys/dev/e1000/if_lem.h
===================================================================
--- head/sys/dev/e1000/if_lem.h
+++ head/sys/dev/e1000/if_lem.h
@@ -236,10 +236,8 @@
 #define HW_DEBUGOUT1(S, A)          if (DEBUG_HW) printf(S "\n", A)
 #define HW_DEBUGOUT2(S, A, B)       if (DEBUG_HW) printf(S "\n", A, B)
 
-#define EM_MAX_SCATTER		64
+#define EM_MAX_SCATTER		40
 #define EM_VFTA_SIZE		128
-#define EM_TSO_SIZE		(65535 + sizeof(struct ether_vlan_header))
-#define EM_TSO_SEG_SIZE		4096	/* Max dma segment size */
 #define EM_MSIX_MASK		0x01F00000 /* For 82574 use */
 #define ETH_ZLEN		60
 #define ETH_ADDR_LEN		6