[PATCH 10/19] wifi: rtw88: coex: reassert the antenna path when associating

[luka.gejak@linux.dev]

From: Luka Gejak <luka.gejak@linux.dev>

The vendor ConnectNotify() returns early without sending H2C commands
when BT is disabled, because the scan path has already established the
antenna configuration, coexistence table and PS-TDMA. What it does keep
is a register level reassertion of the PTA antenna at associate start,
without which the antenna can be left pointing at BT across the
authentication exchange.

Add that reassertion, and the pre-authentication H2C sequence that the
join path added later needs.

Signed-off-by: Luka Gejak <luka.gejak@linux.dev>
---
 drivers/net/wireless/realtek/rtw88/coex.c | 46 +++++++++++++++++++++++
 drivers/net/wireless/realtek/rtw88/coex.h |  1 +
 2 files changed, 47 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/coex.c b/drivers/net/wireless/realtek/rtw88/coex.c
index dbe3842b5f6b..dc74e479351d 100644
--- a/drivers/net/wireless/realtek/rtw88/coex.c
+++ b/drivers/net/wireless/realtek/rtw88/coex.c
@@ -1541,6 +1541,23 @@ static void rtw_coex_8723bs_fw_gnt_bt_low(struct rtw_dev *rtwdev)
 	rtw_fw_set_gnt_bt(rtwdev, 0);
 }
 
+static void rtw_coex_8723bs_force_assoc_pta_ant(struct rtw_dev *rtwdev)
+{
+	u32 ant_target;
+
+	if (!rtw_coex_8723bs_bt_disabled(rtwdev))
+		return;
+
+	ant_target = rtw_coex_8723bs_pta_ant_path(rtwdev);
+
+	rtw_coex_8723bs_fw_gnt_bt_low(rtwdev);
+	rtw_coex_set_ant_switch(rtwdev, COEX_SWITCH_CTRL_BY_PTA,
+				COEX_SWITCH_TO_NOCARE);
+	rtw_coex_8723bs_set_cck_pri(rtwdev, true);
+	rtw_coex_8723bs_write_bb_sel_btg(rtwdev, ant_target);
+	rtw_coex_8723bs_restore_pad_ctrl(rtwdev, true);
+}
+
 static void rtw_coex_8723bs_reassert_ant_buffer(struct rtw_dev *rtwdev)
 {
 	u8 sys_func_before;
@@ -1593,6 +1610,24 @@ void rtw_coex_8723bs_scan_workaround(struct rtw_dev *rtwdev)
 	rtw_coex_8723bs_restore_pad_ctrl(rtwdev, true);
 }
 
+/* Replayed immediately before start_clnt_join()/auth: BT_INFO + PS-TDMA type 8
+ * then the forced WiFi PTA antenna path, so the auth window is clean.
+ */
+void rtw_coex_8723bs_pre_auth_h2c(struct rtw_dev *rtwdev)
+{
+	lockdep_assert_held(&rtwdev->mutex);
+
+	if (!rtw_coex_8723bs_bt_disabled(rtwdev))
+		return;
+
+	rtw_fw_query_bt_info(rtwdev);
+	rtw_fw_coex_tdma_type(rtwdev, 0x08, 0x00, 0x00, 0x00, 0x00);
+	rtw_fw_coex_tdma_type(rtwdev, 0x08, 0x00, 0x00, 0x00, 0x00);
+	rtw_fw_coex_tdma_type(rtwdev, 0x08, 0x00, 0x00, 0x00, 0x00);
+	rtw_coex_8723bs_fw_gnt_bt_low(rtwdev);
+	rtw_coex_8723bs_force_assoc_pta_ant(rtwdev);
+}
+
 static const char *rtw_coex_get_algo_string(u8 algo)
 {
 	switch (algo) {
@@ -3115,6 +3150,17 @@ void rtw_coex_connect_notify(struct rtw_dev *rtwdev, u8 type)
 	if (coex->manual_control || coex->stop_dm)
 		return;
 
+	/* 8723BS SDIO BT-disabled: the vendor ConnectNotify() early-returns
+	 * without sending H2Cs; scan_workaround already established the PTA
+	 * path / coex table / PS-TDMA. Keep only the register-level PTA
+	 * reassertion at associate-start.
+	 */
+	if (rtw_coex_8723bs_bt_disabled(rtwdev)) {
+		if (type == COEX_ASSOCIATE_START)
+			rtw_coex_8723bs_force_assoc_pta_ant(rtwdev);
+		return;
+	}
+
 	rtw_coex_write_scbd(rtwdev, COEX_SCBD_ACTIVE | COEX_SCBD_ONOFF, true);
 
 	if (type == COEX_ASSOCIATE_5G_START) {
diff --git a/drivers/net/wireless/realtek/rtw88/coex.h b/drivers/net/wireless/realtek/rtw88/coex.h
index 72b1353c9313..c58ae0a50b30 100644
--- a/drivers/net/wireless/realtek/rtw88/coex.h
+++ b/drivers/net/wireless/realtek/rtw88/coex.h
@@ -431,5 +431,6 @@ static inline void rtw_coex_active_query_bt_info(struct rtw_dev *rtwdev)
 }
 
 void rtw_coex_8723bs_scan_workaround(struct rtw_dev *rtwdev);
+void rtw_coex_8723bs_pre_auth_h2c(struct rtw_dev *rtwdev);
 
 #endif
-- 
2.55.0