Index: sys/dev/cxgbe/cxgbei/cxgbei.c
===================================================================
--- sys/dev/cxgbe/cxgbei/cxgbei.c
+++ sys/dev/cxgbe/cxgbei/cxgbei.c
@@ -315,13 +315,13 @@
 
 	tp = intotcpcb(inp);
 	MPASS(icp->icp_seq == tp->rcv_nxt);
-	MPASS(tp->rcv_wnd >= pdu_len);
 	tp->rcv_nxt += pdu_len;
-	tp->rcv_wnd -= pdu_len;
 	tp->t_rcvtime = ticks;
 
-	/* update rx credits */
-	t4_rcvd(&toep->td->tod, tp);	/* XXX: sc->tom_softc.tod */
+	/*
+	 * Don't update the window size or return credits since RX
+	 * flow control is disabled.
+	 */
 
 	so = inp->inp_socket;
 	sb = &so->so_rcv;
Index: sys/dev/cxgbe/cxgbei/icl_cxgbei.c
===================================================================
--- sys/dev/cxgbe/cxgbei/icl_cxgbei.c
+++ sys/dev/cxgbe/cxgbei/icl_cxgbei.c
@@ -591,6 +591,9 @@
 	t4_set_tcb_field(sc, toep->ctrlq, toep, W_TCB_ULP_TYPE,
 	    V_TCB_ULP_TYPE(M_TCB_ULP_TYPE) | V_TCB_ULP_RAW(M_TCB_ULP_RAW), val,
 	    0, 0);
+
+	val = V_TF_RX_FLOW_CONTROL_DISABLE(1ULL);
+	t4_set_tcb_field(sc, toep->ctrlq, toep, W_TCB_T_FLAGS, val, val, 0, 0);
 }
 
 /*