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From:   Ping-Ke Shih <pkshih@realtek.com>
To:     <kvalo@kernel.org>
CC:     <cj.hsieh@realtek.com>, <hsuan8331@realtek.com>,
        <linux-wireless@vger.kernel.org>
Subject: [PATCH 4/5] wifi: rtw89: correct the DCFO tracking flow to improve CFO compensation
Date:   Mon, 16 Oct 2023 14:51:14 +0800
Message-ID: <20231016065115.751662-5-pkshih@realtek.com>
In-Reply-To: <20231016065115.751662-1-pkshih@realtek.com>
References: <20231016065115.751662-1-pkshih@realtek.com>
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From: Cheng-Chieh Hsieh <cj.hsieh@realtek.com>

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>
---
 drivers/net/wireless/realtek/rtw89/phy.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/phy.c b/drivers/net/wireless/realtek/rtw89/phy.c
index c7d8faa6265c..3b671a314e60 100644
--- 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) {
-- 
2.25.1