diff --git a/sys/dev/ixl/ixl_txrx.c b/sys/dev/ixl/ixl_txrx.c
index e589bb839..61963848d 100644
--- a/sys/dev/ixl/ixl_txrx.c
+++ b/sys/dev/ixl/ixl_txrx.c
@@ -333,7 +333,6 @@ ixl_tso_setup(struct tx_ring *txr, if_pkt_info_t pi)
  *  	- return 0 on success, positive on failure
   *
   **********************************************************************/
-#define IXL_TXD_CMD (I40E_TX_DESC_CMD_EOP | I40E_TX_DESC_CMD_RS)
 
 static int
 ixl_isc_txd_encap(void *arg, if_pkt_info_t pi)
@@ -398,7 +397,10 @@ ixl_isc_txd_encap(void *arg, if_pkt_info_t pi)
 	}
 	/* Set the last descriptor for report */
 	txd->cmd_type_offset_bsz |=
-	    htole64(((u64)IXL_TXD_CMD << I40E_TXD_QW1_CMD_SHIFT));
+	    htole64(((u64)I40E_TX_DESC_CMD_EOP << I40E_TXD_QW1_CMD_SHIFT));
+	if (tx_intr)
+		txd->cmd_type_offset_bsz |=
+		    htole64(((u64)I40E_TX_DESC_CMD_RS << I40E_TXD_QW1_CMD_SHIFT));
 	/* Add to report status array (if using TX interrupts) */
 	if (!vsi->enable_head_writeback && tx_intr) {
 		txr->tx_rsq[txr->tx_rs_pidx] = pidx_last;
diff --git a/sys/net/iflib.c b/sys/net/iflib.c
index 85c29f850..2fd5cb182 100644
--- a/sys/net/iflib.c
+++ b/sys/net/iflib.c
@@ -190,6 +190,7 @@ struct iflib_ctx {
 	uint16_t ifc_sysctl_nrxqs;
 	uint16_t ifc_sysctl_qs_eq_override;
 	uint16_t ifc_sysctl_rx_budget;
+	uint16_t ifc_sysctl_nm_tx_tmr_us;
 	uint16_t ifc_sysctl_tx_abdicate;
 	uint16_t ifc_sysctl_core_offset;
 #define	CORE_OFFSET_UNSPECIFIED	0xffff
@@ -346,6 +347,9 @@ struct iflib_txq {
 	qidx_t		ift_size;
 	uint16_t	ift_id;
 	struct callout	ift_timer;
+#ifdef DEV_NETMAP
+	struct callout	ift_netmap_timer;
+#endif /* DEV_NETMAP */
 
 	if_txsd_vec_t	ift_sds;
 	uint8_t		ift_qstatus;
@@ -753,6 +757,7 @@ iflib_num_tx_descs(if_ctx_t ctx)
 MODULE_DEPEND(iflib, netmap, 1, 1, 1);
 
 static int netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, bool init);
+static void iflib_netmap_timer(void *arg);
 
 /*
  * device-specific sysctl variables:
@@ -1058,11 +1063,17 @@ iflib_netmap_txsync(struct netmap_kring *kring, int flags)
 			kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
 		}
 	}
+
 	if (!(ctx->ifc_flags & IFC_NETMAP_TX_IRQ))
 		if (kring->nr_hwtail != nm_prev(kring->nr_hwcur, lim)) {
-			callout_reset_on(&txq->ift_timer, hz < 2000 ? 1 : hz / 1000,
-			    iflib_timer, txq, txq->ift_timer.c_cpu);
-	}
+			uint16_t timer_us = ctx->ifc_sysctl_nm_tx_tmr_us;
+
+			if (timer_us == 0)
+				timer_us = 500;
+			callout_reset_sbt(&txq->ift_netmap_timer,
+			    timer_us * SBT_1US, SBT_1US, iflib_netmap_timer,
+			    txq, 0);
+		}
 	return (0);
 }
 
@@ -1263,28 +1274,12 @@ iflib_netmap_rxq_init(if_ctx_t ctx, iflib_rxq_t rxq)
 }
 
 static void
-iflib_netmap_timer_adjust(if_ctx_t ctx, iflib_txq_t txq, uint32_t *reset_on)
+iflib_netmap_timer(void *arg)
 {
-	struct netmap_kring *kring;
-	uint16_t txqid;
-
-	txqid = txq->ift_id;
-	kring = netmap_kring_on(NA(ctx->ifc_ifp), txqid, NR_TX);
-	if (kring == NULL)
-		return;
+	iflib_txq_t txq = arg;
+	if_ctx_t ctx = txq->ift_ctx;
 
-	if (kring->nr_hwcur != nm_next(kring->nr_hwtail, kring->nkr_num_slots - 1)) {
-		bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
-		    BUS_DMASYNC_POSTREAD);
-		if (ctx->isc_txd_credits_update(ctx->ifc_softc, txqid, false))
-			netmap_tx_irq(ctx->ifc_ifp, txqid);
-		if (!(ctx->ifc_flags & IFC_NETMAP_TX_IRQ)) {
-			if (hz < 2000)
-				*reset_on = 1;
-			else
-				*reset_on = hz / 1000;
-		}
-	}
+	netmap_tx_irq(ctx->ifc_ifp, txq->ift_id);
 }
 
 #define iflib_netmap_detach(ifp) netmap_detach(ifp)
@@ -1296,8 +1291,6 @@ iflib_netmap_timer_adjust(if_ctx_t ctx, iflib_txq_t txq, uint32_t *reset_on)
 
 #define iflib_netmap_attach(ctx) (0)
 #define netmap_rx_irq(ifp, qid, budget) (0)
-#define netmap_tx_irq(ifp, qid) do {} while (0)
-#define iflib_netmap_timer_adjust(ctx, txq, reset_on)
 #endif
 
 #if defined(__i386__) || defined(__amd64__)
@@ -2287,7 +2280,6 @@ iflib_timer(void *arg)
 	if_ctx_t ctx = txq->ift_ctx;
 	if_softc_ctx_t sctx = &ctx->ifc_softc_ctx;
 	uint64_t this_tick = ticks;
-	uint32_t reset_on = hz / 2;
 
 	if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING))
 		return;
@@ -2312,17 +2304,13 @@ iflib_timer(void *arg)
 		}
 		txq->ift_cleaned_prev = txq->ift_cleaned;
 	}
-#ifdef DEV_NETMAP
-	if (if_getcapenable(ctx->ifc_ifp) & IFCAP_NETMAP)
-		iflib_netmap_timer_adjust(ctx, txq, &reset_on);
-#endif
 	/* handle any laggards */
 	if (txq->ift_db_pending)
 		GROUPTASK_ENQUEUE(&txq->ift_task);
 
 	sctx->isc_pause_frames = 0;
 	if (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING) 
-		callout_reset_on(&txq->ift_timer, reset_on, iflib_timer, txq, txq->ift_timer.c_cpu);
+		callout_reset_on(&txq->ift_timer, hz / 2, iflib_timer, txq, txq->ift_timer.c_cpu);
 	return;
 
  hung:
@@ -2396,6 +2384,9 @@ iflib_init_locked(if_ctx_t ctx)
 	for (i = 0, txq = ctx->ifc_txqs; i < sctx->isc_ntxqsets; i++, txq++) {
 		CALLOUT_LOCK(txq);
 		callout_stop(&txq->ift_timer);
+#ifdef DEV_NETMAP
+		callout_stop(&txq->ift_netmap_timer);
+#endif /* DEV_NETMAP */
 		CALLOUT_UNLOCK(txq);
 		iflib_netmap_txq_init(ctx, txq);
 	}
@@ -2485,6 +2476,9 @@ iflib_stop(if_ctx_t ctx)
 
 		CALLOUT_LOCK(txq);
 		callout_stop(&txq->ift_timer);
+#ifdef DEV_NETMAP
+		callout_stop(&txq->ift_netmap_timer);
+#endif /* DEV_NETMAP */
 		CALLOUT_UNLOCK(txq);
 
 		/* clean any enqueued buffers */
@@ -3882,7 +3876,6 @@ _task_fn_admin(void *context)
 	iflib_txq_t txq;
 	int i;
 	bool oactive, running, do_reset, do_watchdog, in_detach;
-	uint32_t reset_on = hz / 2;
 
 	STATE_LOCK(ctx);
 	running = (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING);
@@ -3910,12 +3903,7 @@ _task_fn_admin(void *context)
 	}
 	IFDI_UPDATE_ADMIN_STATUS(ctx);
 	for (txq = ctx->ifc_txqs, i = 0; i < sctx->isc_ntxqsets; i++, txq++) {
-#ifdef DEV_NETMAP
-		reset_on = hz / 2;
-		if (if_getcapenable(ctx->ifc_ifp) & IFCAP_NETMAP)
-			iflib_netmap_timer_adjust(ctx, txq, &reset_on);
-#endif
-		callout_reset_on(&txq->ift_timer, reset_on, iflib_timer, txq, txq->ift_timer.c_cpu);
+		callout_reset_on(&txq->ift_timer, hz / 2, iflib_timer, txq, txq->ift_timer.c_cpu);
 	}
 	IFDI_LINK_INTR_ENABLE(ctx);
 	if (do_reset)
@@ -5088,6 +5076,9 @@ iflib_pseudo_deregister(if_ctx_t ctx)
 	tqg = qgroup_if_io_tqg;
 	for (txq = ctx->ifc_txqs, i = 0; i < NTXQSETS(ctx); i++, txq++) {
 		callout_drain(&txq->ift_timer);
+#ifdef DEV_NETMAP
+		callout_drain(&txq->ift_netmap_timer);
+#endif /* DEV_NETMAP */
 		if (txq->ift_task.gt_uniq != NULL)
 			taskqgroup_detach(tqg, &txq->ift_task);
 	}
@@ -5174,6 +5165,9 @@ iflib_device_deregister(if_ctx_t ctx)
 	tqg = qgroup_if_io_tqg;
 	for (txq = ctx->ifc_txqs, i = 0; i < NTXQSETS(ctx); i++, txq++) {
 		callout_drain(&txq->ift_timer);
+#ifdef DEV_NETMAP
+		callout_drain(&txq->ift_netmap_timer);
+#endif /* DEV_NETMAP */
 		if (txq->ift_task.gt_uniq != NULL)
 			taskqgroup_detach(tqg, &txq->ift_task);
 	}
@@ -5583,8 +5577,6 @@ iflib_queues_alloc(if_ctx_t ctx)
 		} else {
 			txq->ift_br_offset = 0;
 		}
-		/* XXX fix this */
-		txq->ift_timer.c_cpu = cpu;
 
 		if (iflib_txsd_alloc(txq)) {
 			device_printf(dev, "Critical Failure setting up TX buffers\n");
@@ -5597,6 +5589,9 @@ iflib_queues_alloc(if_ctx_t ctx)
 		    device_get_nameunit(dev), txq->ift_id);
 		mtx_init(&txq->ift_mtx, txq->ift_mtx_name, NULL, MTX_DEF);
 		callout_init_mtx(&txq->ift_timer, &txq->ift_mtx, 0);
+#ifdef DEV_NETMAP
+		callout_init_mtx(&txq->ift_netmap_timer, &txq->ift_mtx, 0);
+#endif /* DEV_NETMAP */
 
 		err = ifmp_ring_alloc(&txq->ift_br, 2048, txq, iflib_txq_drain,
 				      iflib_txq_can_drain, M_IFLIB, M_WAITOK);
@@ -6610,6 +6605,9 @@ iflib_add_device_sysctl_pre(if_ctx_t ctx)
 	SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "rx_budget",
 		       CTLFLAG_RWTUN, &ctx->ifc_sysctl_rx_budget, 0,
 		       "set the RX budget");
+	SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "nm_tx_tmr_us",
+		       CTLFLAG_RWTUN, &ctx->ifc_sysctl_nm_tx_tmr_us, 0,
+		       "set the TX netmap timer period");
 	SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "tx_abdicate",
 		       CTLFLAG_RWTUN, &ctx->ifc_sysctl_tx_abdicate, 0,
 		       "cause TX to abdicate instead of running to completion");