wifi: rtw89: correct the DCFO tracking flow to improve CFO compensation

DCFO tracking compensate the CFO (carrier frequency offset) by digital
hardware that provides fine CFO estimation. Although the avg_cfo which
is a coarse information becomes zero, still we need DCFO tracking to
compensate the residual CFO. However, the original flow skips the case
when avg_cfo is zero, so we fix it to have expected performance.
Signed-off-by: Cheng-Chieh Hsieh <cj.hsieh@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20231016065115.751662-5-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/phy.c

@@ -2634,6 +2634,10 @@ static void rtw89_phy_cfo_crystal_cap_adjust(struct rtw89_dev *rtwdev,
 	s32 cfo_abs = abs(curr_cfo);
 	int sign;
 
+	if (curr_cfo == 0) {
+		rtw89_debug(rtwdev, RTW89_DBG_CFO, "curr_cfo=0\n");
+		return;
+	}
 	if (!cfo->is_adjust) {
 		if (cfo_abs > CFO_TRK_ENABLE_TH)
 			cfo->is_adjust = true;
@@ -2830,10 +2834,6 @@ static void rtw89_phy_cfo_dm(struct rtw89_dev *rtwdev)
 		new_cfo = rtw89_phy_average_cfo_calc(rtwdev);
 	else
 		new_cfo = rtw89_phy_multi_sta_cfo_calc(rtwdev);
-	if (new_cfo == 0) {
-		rtw89_debug(rtwdev, RTW89_DBG_CFO, "curr_cfo=0\n");
-		return;
-	}
 	if (cfo->divergence_lock_en) {
 		cfo->lock_cnt++;
 		if (cfo->lock_cnt > CFO_PERIOD_CNT) {