wifi: mt76: mt7915: fix chainmask handling for non-dbdc phys on band 1

On single-adie mt7986 the only phy is bound to band 1, but its chainmask
is stored unshifted, because dev->chainshift is still zero while the
eeprom is parsed for the main phy. mt7915_set_antenna() on the other
hand shifts by chainshift * band_idx, so the representation of the
chainmask changed as soon as the antenna configuration was touched.
Until then, mt7915_mcu_set_chan_info() passed rx_path = 0 to the
firmware, since shifting the unshifted mask down clears all bits.

Keep the unshifted form for that case and add helpers for the band local
chainmask, so that only the band 1 phy of a dbdc device uses the shifted
form.

Fixes: 3eb50cc90534 ("wifi: mt76: mt7915: rely on band_idx of mt76_phy")
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Felix Fietkau <[email protected]>

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;

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);

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],
 	};

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;

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;