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

diff --git a/drivers/net/wireless/realtek/rtw89/phy.c b/drivers/net/wireless/realtek/rtw89/phy.c
index c7d8faa6265c732196b1ab25a6fce0d414c17bcd..3b671a314e6089eed71ca40cdbb07b3051dff2af 100644 (file)
--- a/drivers/net/wireless/realtek/rtw89/phy.c
+++ b/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) {