[PATCH 2/4] wifi: mt76: mt7921: fix returned txpower

[Razvan Grigore <razvan.grigore@vampirebyte.ro>]

This bug was noticed by me and confirmed by many more people using this chipset with openwrt: https://github.com/openwrt/mt76/issues/783

It seems that for this particular chipset the mt76_phy->txpower_cur is never set, like in the case of other chipsets like mt7603, mt7615, etc. The driver is correctly calculating the TX power adjustment based on the number of antennas. However, the base TX power (phy->txpower_cur) is not being properly initialized or set to a meaningful value. It's starting at 0, so the final result is just the antenna gain compensation divided by 2.

Signed-off-by: Razvan Grigore <razvan.grigore@vampirebyte.ro>
---
 drivers/net/wireless/mediatek/mt76/mt7921/main.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/main.c b/drivers/net/wireless/mediatek/mt76/mt7921/main.c
index 13e58c328aff..9e8961533fd1 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/main.c
@@ -1251,6 +1251,8 @@ int mt7921_set_tx_sar_pwr(struct ieee80211_hw *hw,
 			  const struct cfg80211_sar_specs *sar)
 {
 	struct mt76_phy *mphy = hw->priv;
+	int tx_power;
+	struct mt76_power_limits limits_array;
 
 	if (sar) {
 		int err = mt76_init_sar_power(hw, sar);
@@ -1260,6 +1262,11 @@ int mt7921_set_tx_sar_pwr(struct ieee80211_hw *hw,
 	}
 	mt792x_init_acpi_sar_power(mt792x_hw_phy(hw), !sar);
 
+	tx_power = mt76_get_power_bound(mphy, hw->conf.power_level);
+	tx_power = mt76_get_rate_power_limits(mphy, mphy->chandef.chan,
+					      &limits_array, tx_power);
+	mphy->txpower_cur = tx_power;
+
 	return mt76_connac_mcu_set_rate_txpower(mphy);
 }
 
-- 
2.34.1