wifi: rtw89: release RX standby timer of beamformee CSI to save power

Originally, we keep RX standby timer to handle beamformee CSI, but this
spends power and causes system not entering power save mode. To improve
power consumption, release the timer if throughput becomes low.
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230307141848.26403-1-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/core.h

@@ -3168,6 +3168,7 @@ enum rtw89_flags {
 	RTW89_FLAG_RUNNING,
 	RTW89_FLAG_BFEE_MON,
 	RTW89_FLAG_BFEE_EN,
+	RTW89_FLAG_BFEE_TIMER_KEEP,
 	RTW89_FLAG_NAPI_RUNNING,
 	RTW89_FLAG_LEISURE_PS,
 	RTW89_FLAG_LOW_POWER_MODE,

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

@@ -4931,6 +4931,24 @@ u16 rtw89_mac_get_plt_cnt(struct rtw89_dev *rtwdev, u8 band)
 	return cnt;
 }
 
+static void rtw89_mac_bfee_standby_timer(struct rtw89_dev *rtwdev, u8 mac_idx,
+					 bool keep)
+{
+	u32 reg;
+
+	rtw89_debug(rtwdev, RTW89_DBG_BF, "set bfee standby_timer to %d\n", keep);
+	reg = rtw89_mac_reg_by_idx(R_AX_BFMEE_RESP_OPTION, mac_idx);
+	if (keep) {
+		set_bit(RTW89_FLAG_BFEE_TIMER_KEEP, rtwdev->flags);
+		rtw89_write32_mask(rtwdev, reg, B_AX_BFMEE_BFRP_RX_STANDBY_TIMER_MASK,
+				   BFRP_RX_STANDBY_TIMER_KEEP);
+	} else {
+		clear_bit(RTW89_FLAG_BFEE_TIMER_KEEP, rtwdev->flags);
+		rtw89_write32_mask(rtwdev, reg, B_AX_BFMEE_BFRP_RX_STANDBY_TIMER_MASK,
+				   BFRP_RX_STANDBY_TIMER_RELEASE);
+	}
+}
+
 static void rtw89_mac_bfee_ctrl(struct rtw89_dev *rtwdev, u8 mac_idx, bool en)
 {
 	u32 reg;
@@ -4967,9 +4985,9 @@ static int rtw89_mac_init_bfee(struct rtw89_dev *rtwdev, u8 mac_idx)
 	rtw89_write32(rtwdev, reg, CSI_RRSC_BMAP);
 
 	reg = rtw89_mac_reg_by_idx(R_AX_BFMEE_RESP_OPTION, mac_idx);
-	val32 = FIELD_PREP(B_AX_BFMEE_BFRP_RX_STANDBY_TIMER_MASK, BFRP_RX_STANDBY_TIMER);
-	val32 |= FIELD_PREP(B_AX_BFMEE_NDP_RX_STANDBY_TIMER_MASK, NDP_RX_STANDBY_TIMER);
+	val32 = FIELD_PREP(B_AX_BFMEE_NDP_RX_STANDBY_TIMER_MASK, NDP_RX_STANDBY_TIMER);
 	rtw89_write32(rtwdev, reg, val32);
+	rtw89_mac_bfee_standby_timer(rtwdev, mac_idx, true);
 	rtw89_mac_bfee_ctrl(rtwdev, mac_idx, true);
 
 	reg = rtw89_mac_reg_by_idx(R_AX_TRXPTCL_RESP_CSI_CTRL_0, mac_idx);
@@ -5181,6 +5199,19 @@ void _rtw89_mac_bf_monitor_track(struct rtw89_dev *rtwdev)
 	struct rtw89_vif *rtwvif;
 	bool en = stats->tx_tfc_lv <= stats->rx_tfc_lv;
 	bool old = test_bit(RTW89_FLAG_BFEE_EN, rtwdev->flags);
+	bool keep_timer = true;
+	bool old_keep_timer;
+
+	old_keep_timer = test_bit(RTW89_FLAG_BFEE_TIMER_KEEP, rtwdev->flags);
+
+	if (stats->tx_tfc_lv <= RTW89_TFC_LOW && stats->rx_tfc_lv <= RTW89_TFC_LOW)
+		keep_timer = false;
+
+	if (keep_timer != old_keep_timer) {
+		rtw89_for_each_rtwvif(rtwdev, rtwvif)
+			rtw89_mac_bfee_standby_timer(rtwdev, rtwvif->mac_idx,
+						     keep_timer);
+	}
 
 	if (en == old)
 		return;

drivers/net/wireless/realtek/rtw89/reg.h

@@ -3056,6 +3056,8 @@
 #define R_AX_BFMEE_RESP_OPTION_C1 0xED80
 #define B_AX_BFMEE_NDP_RX_STANDBY_TIMER_MASK GENMASK(31, 24)
 #define B_AX_BFMEE_BFRP_RX_STANDBY_TIMER_MASK GENMASK(23, 20)
+#define BFRP_RX_STANDBY_TIMER_KEEP 0x0
+#define BFRP_RX_STANDBY_TIMER_RELEASE 0x1
 #define B_AX_MU_BFRPTSEG_SEL_MASK GENMASK(18, 17)
 #define B_AX_BFMEE_NDP_RXSTDBY_SEL BIT(16)
 #define BFRP_RX_STANDBY_TIMER		0x0