Index: adapter.h
===================================================================
--- adapter.h	(revision 225414)
+++ adapter.h	(working copy)
@@ -533,7 +532,9 @@
 	char fw_version[32];
 	struct adapter_params params;
 	struct t4_virt_res vres;
+	struct tp_err_stats err_stats;
 
+	struct callout tick;
 	struct sysctl_ctx_list ctx; /* from first_port_up to last_port_down */
 	struct sysctl_oid *oid_fwq;
 	struct sysctl_oid *oid_ctrlq;
Index: t4_main.c
===================================================================
--- t4_main.c	(revision 225414)
+++ t4_main.c	(working copy)
@@ -327,6 +318,7 @@
 static void reg_block_dump(struct adapter *, uint8_t *, unsigned int,
     unsigned int);
 static void t4_get_regs(struct adapter *, struct t4_regdump *, uint8_t *);
+static void t4_tick(void *);
 static void cxgbe_tick(void *);
 static int t4_sysctls(struct adapter *);
 static int cxgbe_sysctls(struct port_info *);
@@ -427,6 +419,7 @@
 	    device_get_nameunit(dev));
 	mtx_init(&sc->sc_lock, sc->lockname, 0, MTX_DEF);
 	sx_init(&sc->userq_lock, "userq");
+	callout_init_mtx(&sc->tick, &sc->sc_lock, 0);
 
 	rc = map_bars(sc);
 	if (rc != 0)
@@ -725,6 +718,8 @@
 #endif
 	t4_set_desc(sc);
 
+	callout_reset(&sc->tick, hz, t4_tick, sc);
+	
 done:
 	if (rc != 0)
 		t4_detach(dev);
@@ -756,6 +751,7 @@
 	if (sc->cdev)
 		destroy_dev(sc->cdev);
 
+	callout_drain(&sc->tick);
 	bus_generic_detach(dev);
 	for (i = 0; i < MAX_NPORTS; i++) {
 		pi = sc->port[i];
@@ -838,7 +834,7 @@
 	pi->ifp = ifp;
 	ifp->if_softc = pi;
 
-	callout_init(&pi->tick, CALLOUT_MPSAFE);
+	callout_init_mtx(&pi->tick, &pi->pi_lock, 0);
 	pi->tq = taskqueue_create("cxgbe_taskq", M_NOWAIT,
 	    taskqueue_thread_enqueue, &pi->tq);
 	if (pi->tq == NULL) {
@@ -903,6 +899,7 @@
 	if (rc != 0)
 		device_printf(dev, "port uninit failed: %d.\n", rc);
 
+	callout_drain(&pi->tick);
 	taskqueue_free(pi->tq);
 
 	ifmedia_removeall(&pi->media);
@@ -2101,7 +2098,6 @@
 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
 	callout_stop(&pi->tick);
 	PORT_UNLOCK(pi);
-	callout_drain(&pi->tick);
 
 	/*
 	 * Stop and then free the queues' resources, including the queues
@@ -2520,6 +2516,18 @@
 }
 
 static void
+t4_tick(void *arg)
+{
+	struct adapter *sc = arg;
+	struct tp_err_stats *st = &sc->err_stats;
+
+	ADAPTER_LOCK_ASSERT_OWNED(sc);
+	t4_tp_get_err_stats(sc, st);
+
+	callout_schedule(&sc->tick, hz);
+}
+
+static void
 cxgbe_tick(void *arg)
 {
 	struct port_info *pi = arg;
@@ -2528,11 +2536,8 @@
 	int i, drops;
 	struct port_stats *s = &pi->stats;
 
-	PORT_LOCK(pi);
-	if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
-		PORT_UNLOCK(pi);
-		return;	/* without scheduling another callout */
-	}
+	PORT_LOCK_ASSERT_OWNED(pi);
+	KASSERT(ifp->if_drv_flags & IFF_DRV_RUNNING, ("interface down"));
 
 	t4_get_port_stats(pi->adapter, pi->tx_chan, s);
 
@@ -2555,7 +2560,6 @@
 	    s->rx_fcs_err + s->rx_len_err;
 
 	callout_schedule(&pi->tick, hz);
-	PORT_UNLOCK(pi);
 }
 
 static int
@@ -2566,6 +2570,10 @@
 	struct sysctl_oid_list *children;
 
 	ctx = device_get_sysctl_ctx(sc->dev);
+
+	/*
+	 * dev.t4nex.X.
+	 */
 	oid = device_get_sysctl_tree(sc->dev);
 	children = SYSCTL_CHILDREN(oid);
 
@@ -2598,6 +2606,23 @@
 	    sysctl_devlog, "A", "device log");
 #endif
 
+	/*
+	 * dev.t4nex.X.stats.
+	 */
+	oid = SYSCTL_ADD_NODE(ctx, children, OID_AUTO, "stats", CTLFLAG_RD,
+	    NULL, "adapter statistics");
+	children = SYSCTL_CHILDREN(oid);
+	
+	/* We get these from err_stats and they may be stale by up to 1s */
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "cong_drops0", CTLFLAG_RD,
+	    &sc->err_stats.tnlCongDrops[0], 0, "channel 0 congestion drops");
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "cong_drops1", CTLFLAG_RD,
+	    &sc->err_stats.tnlCongDrops[1], 0, "channel 1 congestion drops");
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "cong_drops2", CTLFLAG_RD,
+	    &sc->err_stats.tnlCongDrops[2], 0, "channel 2 congestion drops");
+	SYSCTL_ADD_UINT(ctx, children, OID_AUTO, "cong_drops3", CTLFLAG_RD,
+	    &sc->err_stats.tnlCongDrops[3], 0, "channel 3 congestion drops");
+
 	return (0);
 }
 
@@ -2775,7 +2800,7 @@
 	SYSCTL_ADD_UQUAD(ctx, children, OID_AUTO, #name, CTLFLAG_RD, \
 	    &pi->stats.name, desc)
 
-	/* We get these from port_stats and they may be stale by upto 1s */
+	/* We get these from port_stats and they may be stale by up to 1s */
 	SYSCTL_ADD_T4_PORTSTAT(rx_ovflow0,
 	    "# drops due to buffer-group 0 overflows");
 	SYSCTL_ADD_T4_PORTSTAT(rx_ovflow1,