diff --git a/mt7915/eeprom.c b/mt7915/eeprom.c
index eb92cbf1..fe7b29eb 100644
--- a/mt7915/eeprom.c
+++ b/mt7915/eeprom.c
@@ -257,7 +257,7 @@ void mt7915_eeprom_parse_hw_cap(struct mt7915_dev *dev,
 	nss = min_t(u8, min_t(u8, nss_max, nss), path);
 
 	mphy->chainmask = BIT(path) - 1;
-	if (band)
+	if (band && dev->dbdc_support)
 		mphy->chainmask <<= dev->chainshift;
 	mphy->antenna_mask = BIT(nss) - 1;
 	dev->chainmask |= mphy->chainmask;
diff --git a/mt7915/main.c b/mt7915/main.c
index 157b891d..1f4e997c 100644
--- a/mt7915/main.c
+++ b/mt7915/main.c
@@ -1161,7 +1161,7 @@ mt7915_set_antenna(struct ieee80211_hw *hw, int radio_idx, u32 tx_ant, u32 rx_an
 	struct mt7915_dev *dev = mt7915_hw_dev(hw);
 	struct mt7915_phy *phy = mt7915_hw_phy(hw);
 	int max_nss = hweight8(hw->wiphy->available_antennas_tx);
-	u8 chainshift = dev->chainshift;
+	u8 shift = mt7915_band_chainshift(phy);
 	u8 band = phy->mt76->band_idx;
 
 	if (!tx_ant || tx_ant != rx_ant || ffs(tx_ant) > max_nss)
@@ -1174,9 +1174,9 @@ mt7915_set_antenna(struct ieee80211_hw *hw, int radio_idx, u32 tx_ant, u32 rx_an
 	/* handle a variant of mt7916/mt7981 which has 3T3R but nss2 on 5 GHz band */
 	if ((is_mt7916(&dev->mt76) || is_mt7981(&dev->mt76)) &&
 	    band && hweight8(tx_ant) == max_nss)
-		phy->mt76->chainmask = (dev->chainmask >> chainshift) << chainshift;
+		phy->mt76->chainmask = (dev->chainmask >> shift) << shift;
 	else
-		phy->mt76->chainmask = tx_ant << (chainshift * band);
+		phy->mt76->chainmask = tx_ant << shift;
 
 	mt76_set_stream_caps(phy->mt76, true);
 	mt7915_set_stream_vht_txbf_caps(phy);
diff --git a/mt7915/mcu.c b/mt7915/mcu.c
index a2170b01..12356621 100644
--- a/mt7915/mcu.c
+++ b/mt7915/mcu.c
@@ -2839,7 +2839,7 @@ int mt7915_mcu_set_chan_info(struct mt7915_phy *phy, int cmd)
 		.center_ch = ieee80211_frequency_to_channel(freq1),
 		.bw = mt76_connac_chan_bw(chandef),
 		.tx_path_num = hweight16(phy->mt76->chainmask),
-		.rx_path = phy->mt76->chainmask >> (dev->chainshift * band),
+		.rx_path = mt7915_band_chainmask(phy),
 		.band_idx = band,
 		.channel_band = ch_band[chandef->chan->band],
 	};
diff --git a/mt7915/mt7915.h b/mt7915/mt7915.h
index 8ba26ef5..7ee9bed8 100644
--- a/mt7915/mt7915.h
+++ b/mt7915/mt7915.h
@@ -411,6 +411,24 @@ mt7915_ext_phy(struct mt7915_dev *dev)
 	return phy->priv;
 }
 
+/* without dbdc, the chainmask is stored unshifted, even if the phy is
+ * bound to band 1
+ */
+static inline u8 mt7915_band_chainshift(struct mt7915_phy *phy)
+{
+	struct mt7915_dev *dev = phy->dev;
+
+	if (!dev->dbdc_support)
+		return 0;
+
+	return phy->mt76->band_idx * dev->chainshift;
+}
+
+static inline u16 mt7915_band_chainmask(struct mt7915_phy *phy)
+{
+	return phy->mt76->chainmask >> mt7915_band_chainshift(phy);
+}
+
 static inline u32 mt7915_check_adie(struct mt7915_dev *dev, bool sku)
 {
 	u32 mask = sku ? MT_CONNINFRA_SKU_MASK : MT_ADIE_TYPE_MASK;
diff --git a/mt7915/testmode.c b/mt7915/testmode.c
index 618a5c2b..7576973f 100644
--- a/mt7915/testmode.c
+++ b/mt7915/testmode.c
@@ -694,9 +694,7 @@ mt7915_tm_set_params(struct mt76_phy *mphy, struct nlattr **tb,
 {
 	struct mt76_testmode_data *td = &mphy->test;
 	struct mt7915_phy *phy = mphy->priv;
-	struct mt7915_dev *dev = phy->dev;
-	u32 chainmask = mphy->chainmask, changed = 0;
-	bool ext_phy = phy != &dev->phy;
+	u32 chainmask = mt7915_band_chainmask(phy), changed = 0;
 	int i;
 
 	BUILD_BUG_ON(NUM_TM_CHANGED >= 32);
@@ -705,7 +703,6 @@ mt7915_tm_set_params(struct mt76_phy *mphy, struct nlattr **tb,
 	    td->state == MT76_TM_STATE_OFF)
 		return 0;
 
-	chainmask = ext_phy ? chainmask >> dev->chainshift : chainmask;
 	if (td->tx_antenna_mask > chainmask)
 		return -EINVAL;