diff --git a/sys/dev/cxgbe/common/t4_hw.c b/sys/dev/cxgbe/common/t4_hw.c
index 8a225849930..8d109b389f0 100644
--- a/sys/dev/cxgbe/common/t4_hw.c
+++ b/sys/dev/cxgbe/common/t4_hw.c
@@ -6745,10 +6745,11 @@ static unsigned int t4_get_mps_bg_map(struct adapter *adap, int idx)
 	if (adap->params.mps_bg_map)
 		return ((adap->params.mps_bg_map >> (idx << 3)) & 0xff);
 
-	n = G_NUMPORTS(t4_read_reg(adap, A_MPS_CMN_CTL));
-	if (n == 0)
+	n = adap->params.nports;
+	MPASS(n > 0 && n <= MAX_NPORTS);
+	if (n == 1)
 		return idx == 0 ? 0xf : 0;
-	if (n == 1 && chip_id(adap) <= CHELSIO_T5)
+	if (n == 2 && chip_id(adap) <= CHELSIO_T5)
 		return idx < 2 ? (3 << (2 * idx)) : 0;
 	return 1 << idx;
 }
@@ -6758,12 +6759,12 @@ static unsigned int t4_get_mps_bg_map(struct adapter *adap, int idx)
  */
 static unsigned int t4_get_rx_e_chan_map(struct adapter *adap, int idx)
 {
-	u32 n = G_NUMPORTS(t4_read_reg(adap, A_MPS_CMN_CTL));
+	const u32 n = adap->params.nports;
 	const u32 all_chan = (1 << adap->chip_params->nchan) - 1;
 
-	if (n == 0)
+	if (n == 1)
 		return idx == 0 ? all_chan : 0;
-	if (n == 1 && chip_id(adap) <= CHELSIO_T5)
+	if (n == 2 && chip_id(adap) <= CHELSIO_T5)
 		return idx < 2 ? (3 << (2 * idx)) : 0;
 	return 1 << idx;
 }