[PATCH] staging: rtl8723bs: remove dead antenna diversity infrastructure (FAT/SWAT)

[PATCH] staging: rtl8723bs: remove dead antenna diversity infrastructure (FAT/SWAT)

[Marinela Tatiana Selseth]

Deep analysis reveals that the driver contains major vestigial out-of-tree
architectural frameworks for Fast Antenna Training (FAT) and Software
Antenna Switching (SWAS) that are completely uninitialized, unread, or
write-only.

Remove the 'struct fat_t' definition from hal/odm.h and refactor the
fallback path in hal/rtl8723b_phycfg.c. Because the unassigned structural
member 'RxIdleAnt' naturally defaults to 0, the conditional path check
statically resolves to false, permanently routing RFPath to RF_PATH_B
whenever antenna diversity is active. Hardcode this layout behavior to
match factual reality and remove the now unused macro 'MAIN_ANT'.

Additionally, purge the write-only 'struct swat_t' infrastructure from
hal/odm.h and include/hal_data.h. Inside hal/odm.c, eliminate the dead
variable tracking assignments while explicitly preserving the hardware
register read to rDPDT_control as a dummy read to ensure initialization
sequencing and hardware timing remain completely unaltered.

Lastly, clean up legacy comment baggage across hal/odm.c and
hal/odm_DIG.c. Remove arbitrary spreadsheet digits and references to
unsupported legacy chipsets (92E, 8723A, 8821, 8812) to ensure inline
notes are highly focused on the active RTL8723B Bluetooth coexistence
parameters.

Signed-off-by: Marinela Tatiana Selseth <marinela.selseth@firmwaredesign.org>
---
 drivers/staging/rtl8723bs/hal/odm.c           |  12 +--
 drivers/staging/rtl8723bs/hal/odm.h           | 100 ------------------
 drivers/staging/rtl8723bs/hal/odm_DIG.c       |   5 +-
 .../staging/rtl8723bs/hal/rtl8723b_phycfg.c   |  11 +-
 drivers/staging/rtl8723bs/include/hal_data.h  |   1 -
 5 files changed, 11 insertions(+), 118 deletions(-)

diff --git a/drivers/staging/rtl8723bs/hal/odm.c b/drivers/staging/rtl8723bs/hal/odm.c
index f3989fa33d9f..00b938071dee 100644
--- a/drivers/staging/rtl8723bs/hal/odm.c
+++ b/drivers/staging/rtl8723bs/hal/odm.c
@@ -461,12 +461,8 @@ static void odm_RSSIMonitorCheck(struct dm_odm_t *pDM_Odm)
 /* 3 ============================================================ */
 static void odm_SwAntDetectInit(struct dm_odm_t *pDM_Odm)
 {
-	struct swat_t *pDM_SWAT_Table = &pDM_Odm->DM_SWAT_Table;
-
-	pDM_SWAT_Table->SWAS_NoLink_BK_Reg92c = rtw_read32(pDM_Odm->Adapter, rDPDT_control);
-	pDM_SWAT_Table->PreAntenna = MAIN_ANT;
-	pDM_SWAT_Table->CurAntenna = MAIN_ANT;
-	pDM_SWAT_Table->SWAS_NoLink_State = 0;
+	/* Dummy read rDPDT_control to preserve initialization hardware sequencing */
+	rtw_read32(pDM_Odm->Adapter, rDPDT_control);
 }
 
 /* 3 ============================================================ */
@@ -589,9 +585,7 @@ void ODM_DMWatchdog(struct dm_odm_t *pDM_Odm)
 
 	odm_RSSIMonitorCheck(pDM_Odm);
 
-	/* For CE Platform(SPRD or Tablet) */
-	/* 8723A or 8189ES platform */
-	/* NeilChen--2012--08--24-- */
+	/* For CE Platform (Spreadtrum or Tablet) */
 	/* Fix Leave LPS issue */
 	if (adapter_to_pwrctl(pDM_Odm->Adapter)->pwr_mode != PS_MODE_ACTIVE) {
 		/* in LPS mode */
diff --git a/drivers/staging/rtl8723bs/hal/odm.h b/drivers/staging/rtl8723bs/hal/odm.h
index 3532f0d79363..88f4b6f0c410 100644
--- a/drivers/staging/rtl8723bs/hal/odm.h
+++ b/drivers/staging/rtl8723bs/hal/odm.h
@@ -50,12 +50,6 @@
 #define	PSD_RESCAN		4
 #define	PSD_SCAN_INTERVAL	700 /* ms */
 
-/* 8723A High Power IGI Setting */
-#define		DM_DIG_HIGH_PWR_IGI_LOWER_BOUND	0x22
-#define			DM_DIG_Gmode_HIGH_PWR_IGI_LOWER_BOUND 0x28
-#define		DM_DIG_HIGH_PWR_THRESHOLD	0x3a
-#define		DM_DIG_LOW_PWR_THRESHOLD	0x14
-
 /* ANT Test */
 #define			ANTTESTALL		0x00		/* Ant A or B will be Testing */
 #define		ANTTESTA		0x01		/* Ant A will be Testing */
@@ -63,11 +57,6 @@
 
 #define	PS_MODE_ACTIVE 0x01
 
-/* for 8723A Ant Definition--2012--06--07 due to different IC may be different ANT define */
-#define		MAIN_ANT		1		/* Ant A or Ant Main */
-#define		AUX_ANT		2		/* AntB or Ant Aux */
-#define		MAX_ANT		3		/*  3 for AP using */
-
 /* Antenna Diversity Type */
 #define	SW_ANTDIV	0
 #define	HW_ANTDIV	1
@@ -123,54 +112,6 @@ struct rxhp_t {
 #define	TRAFFIC_HIGH	1
 #define	TRAFFIC_UltraLOW	2
 
-struct swat_t { /* _SW_Antenna_Switch_ */
-	u8 Double_chk_flag;
-	u8 try_flag;
-	s32 PreRSSI;
-	u8 CurAntenna;
-	u8 PreAntenna;
-	u8 RSSI_Trying;
-	u8 TestMode;
-	u8 bTriggerAntennaSwitch;
-	u8 SelectAntennaMap;
-	u8 RSSI_target;
-	u8 reset_idx;
-	u16 Single_Ant_Counter;
-	u16 Dual_Ant_Counter;
-	u16 Aux_FailDetec_Counter;
-	u16 Retry_Counter;
-
-	/*  Before link Antenna Switch check */
-	u8 SWAS_NoLink_State;
-	u32 SWAS_NoLink_BK_Reg860;
-	u32 SWAS_NoLink_BK_Reg92c;
-	u32 SWAS_NoLink_BK_Reg948;
-	bool ANTA_ON;	/* To indicate Ant A is or not */
-	bool ANTB_ON;	/* To indicate Ant B is on or not */
-	bool Pre_Aux_FailDetec;
-	bool RSSI_AntDect_bResult;
-	u8 Ant2G;
-
-	s32 RSSI_sum_A;
-	s32 RSSI_sum_B;
-	s32 RSSI_cnt_A;
-	s32 RSSI_cnt_B;
-
-	u64 lastTxOkCnt;
-	u64 lastRxOkCnt;
-	u64 TXByteCnt_A;
-	u64 TXByteCnt_B;
-	u64 RXByteCnt_A;
-	u64 RXByteCnt_B;
-	u8 TrafficLoad;
-	u8 Train_time;
-	u8 Train_time_flag;
-	struct timer_list SwAntennaSwitchTimer;
-	struct timer_list SwAntennaSwitchTimer_8723B;
-	u32 PktCnt_SWAntDivByCtrlFrame;
-	bool bSWAntDivByCtrlFrame;
-};
-
 /* Remove Edca by YuChen */
 
 struct odm_rate_adaptive {
@@ -557,45 +498,6 @@ struct odm_rf_cal_t { /* ODM_RF_Calibration_Structure */
 
 };
 
-/*  ODM Dynamic common info value definition */
-struct fat_t { /* _FAST_ANTENNA_TRAINNING_ */
-	u8 Bssid[6];
-	u8 antsel_rx_keep_0;
-	u8 antsel_rx_keep_1;
-	u8 antsel_rx_keep_2;
-	u8 antsel_rx_keep_3;
-	u32 antSumRSSI[7];
-	u32 antRSSIcnt[7];
-	u32 antAveRSSI[7];
-	u8 FAT_State;
-	u32 TrainIdx;
-	u8 antsel_a[ODM_ASSOCIATE_ENTRY_NUM];
-	u8 antsel_b[ODM_ASSOCIATE_ENTRY_NUM];
-	u8 antsel_c[ODM_ASSOCIATE_ENTRY_NUM];
-	u32 MainAnt_Sum[ODM_ASSOCIATE_ENTRY_NUM];
-	u32 AuxAnt_Sum[ODM_ASSOCIATE_ENTRY_NUM];
-	u32 MainAnt_Cnt[ODM_ASSOCIATE_ENTRY_NUM];
-	u32 AuxAnt_Cnt[ODM_ASSOCIATE_ENTRY_NUM];
-	u8 RxIdleAnt;
-	bool	bBecomeLinked;
-	u32 MinMaxRSSI;
-	u8 idx_AntDiv_counter_2G;
-	u32 CCK_counter_main;
-	u32 CCK_counter_aux;
-	u32 OFDM_counter_main;
-	u32 OFDM_counter_aux;
-
-	u32 CCK_CtrlFrame_Cnt_main;
-	u32 CCK_CtrlFrame_Cnt_aux;
-	u32 OFDM_CtrlFrame_Cnt_main;
-	u32 OFDM_CtrlFrame_Cnt_aux;
-	u32 MainAnt_CtrlFrame_Sum;
-	u32 AuxAnt_CtrlFrame_Sum;
-	u32 MainAnt_CtrlFrame_Cnt;
-	u32 AuxAnt_CtrlFrame_Cnt;
-
-};
-
 enum {
 	NO_ANTDIV			= 0xFF,
 	CG_TRX_HW_ANTDIV		= 0x01,
@@ -828,7 +730,6 @@ struct dm_odm_t { /* DM_Out_Source_Dynamic_Mechanism_Structure */
 	struct odm_mac_status_info *pMacInfo;
 
 	/* ODM Structure */
-	struct fat_t DM_FatTable;
 	struct dig_t DM_DigTable;
 	struct ps_t DM_PSTable;
 	struct dynamic_primary_CCA DM_PriCCA;
@@ -836,7 +737,6 @@ struct dm_odm_t { /* DM_Out_Source_Dynamic_Mechanism_Structure */
 	struct ra_t DM_RA_Table;
 	struct false_ALARM_STATISTICS FalseAlmCnt;
 	struct false_ALARM_STATISTICS FlaseAlmCntBuddyAdapter;
-	struct swat_t DM_SWAT_Table;
 	bool RSSI_test;
 	struct cfo_tracking DM_CfoTrack;
 
diff --git a/drivers/staging/rtl8723bs/hal/odm_DIG.c b/drivers/staging/rtl8723bs/hal/odm_DIG.c
index c862c86b7695..44932b2c9f9f 100644
--- a/drivers/staging/rtl8723bs/hal/odm_DIG.c
+++ b/drivers/staging/rtl8723bs/hal/odm_DIG.c
@@ -395,10 +395,9 @@ void odm_DIG(void *pDM_VOID)
 	dm_dig_min = DM_DIG_MIN_NIC;
 	DIG_MaxOfMin = DM_DIG_MAX_AP;
 
-	/* 1 Adjust boundary by RSSI */
+	/* Adjust boundary by RSSI */
 	if (pDM_Odm->bLinked && bPerformance) {
-		/* 2 Modify DIG upper bound */
-		/* 4 Modify DIG upper bound for 92E, 8723A\B, 8821 & 8812 BT */
+		/* Modify DIG upper bound for 8723B BT */
 		if (pDM_Odm->bBtLimitedDig == 1)
 			offset = 10;
 		else
diff --git a/drivers/staging/rtl8723bs/hal/rtl8723b_phycfg.c b/drivers/staging/rtl8723bs/hal/rtl8723b_phycfg.c
index 3c99621311e5..18fb3fe4ecfd 100644
--- a/drivers/staging/rtl8723bs/hal/rtl8723b_phycfg.c
+++ b/drivers/staging/rtl8723bs/hal/rtl8723b_phycfg.c
@@ -527,13 +527,14 @@ u8 PHY_GetTxPowerIndex(
 void PHY_SetTxPowerLevel8723B(struct adapter *Adapter, u8 Channel)
 {
 	struct hal_com_data *pHalData = GET_HAL_DATA(Adapter);
-	struct dm_odm_t *pDM_Odm = &pHalData->odmpriv;
-	struct fat_t *pDM_FatTable = &pDM_Odm->DM_FatTable;
 	u8 RFPath = RF_PATH_A;
 
-	if (pHalData->AntDivCfg) {/*  antenna diversity Enable */
-		RFPath = ((pDM_FatTable->RxIdleAnt == MAIN_ANT) ? RF_PATH_A : RF_PATH_B);
-	} else { /*  antenna diversity disable */
+	if (pHalData->AntDivCfg) {/* antenna diversity enable */
+		/* Antenna diversity forces path B because Fast Antenna Training
+		 * (FAT) logic is unhandled in this staging driver baseline.
+		 */
+		RFPath = RF_PATH_B;
+	} else { /* antenna diversity disable */
 		RFPath = pHalData->ant_path;
 	}
 
diff --git a/drivers/staging/rtl8723bs/include/hal_data.h b/drivers/staging/rtl8723bs/include/hal_data.h
index c345b632bf53..0f346e2a3b17 100644
--- a/drivers/staging/rtl8723bs/include/hal_data.h
+++ b/drivers/staging/rtl8723bs/include/hal_data.h
@@ -209,7 +209,6 @@ struct hal_com_data {
 	u8 RegReg542;
 	u16 RegRRSR;
 
-	u8 CurAntenna;
 	u8 AntDivCfg;
 	u8 AntDetection;
 	u8 ant_path; /* for 8723B s0/s1 selection */
-- 
2.43.0

Re: [PATCH] staging: rtl8723bs: remove dead antenna diversity infrastructure (FAT/SWAT)

[Greg Kroah-Hartman]

On Fri, Oct 02, 2026 at 07:33:41PM -0500, Marinela Tatiana Selseth wrote:
> Deep analysis reveals that the driver contains major vestigial out-of-tree
> architectural frameworks for Fast Antenna Training (FAT) and Software
> Antenna Switching (SWAS) that are completely uninitialized, unread, or
> write-only.

what tool did this "deep analysis"?

> 
> Remove the 'struct fat_t' definition from hal/odm.h and refactor the
> fallback path in hal/rtl8723b_phycfg.c. Because the unassigned structural
> member 'RxIdleAnt' naturally defaults to 0, the conditional path check
> statically resolves to false, permanently routing RFPath to RF_PATH_B
> whenever antenna diversity is active. Hardcode this layout behavior to
> match factual reality and remove the now unused macro 'MAIN_ANT'.
> 
> Additionally, purge the write-only 'struct swat_t' infrastructure from
> hal/odm.h and include/hal_data.h. Inside hal/odm.c, eliminate the dead
> variable tracking assignments while explicitly preserving the hardware
> register read to rDPDT_control as a dummy read to ensure initialization
> sequencing and hardware timing remain completely unaltered.
> 
> Lastly, clean up legacy comment baggage across hal/odm.c and
> hal/odm_DIG.c. Remove arbitrary spreadsheet digits and references to
> unsupported legacy chipsets (92E, 8723A, 8821, 8812) to ensure inline
> notes are highly focused on the active RTL8723B Bluetooth coexistence
> parameters.
> 
> Signed-off-by: Marinela Tatiana Selseth <marinela.selseth@firmwaredesign.org>
> ---
>  drivers/staging/rtl8723bs/hal/odm.c           |  12 +--
>  drivers/staging/rtl8723bs/hal/odm.h           | 100 ------------------
>  drivers/staging/rtl8723bs/hal/odm_DIG.c       |   5 +-
>  .../staging/rtl8723bs/hal/rtl8723b_phycfg.c   |  11 +-
>  drivers/staging/rtl8723bs/include/hal_data.h  |   1 -
>  5 files changed, 11 insertions(+), 118 deletions(-)
> 
> diff --git a/drivers/staging/rtl8723bs/hal/odm.c b/drivers/staging/rtl8723bs/hal/odm.c
> index f3989fa33d9f..00b938071dee 100644
> --- a/drivers/staging/rtl8723bs/hal/odm.c
> +++ b/drivers/staging/rtl8723bs/hal/odm.c
> @@ -461,12 +461,8 @@ static void odm_RSSIMonitorCheck(struct dm_odm_t *pDM_Odm)
>  /* 3 ============================================================ */
>  static void odm_SwAntDetectInit(struct dm_odm_t *pDM_Odm)
>  {
> -	struct swat_t *pDM_SWAT_Table = &pDM_Odm->DM_SWAT_Table;
> -
> -	pDM_SWAT_Table->SWAS_NoLink_BK_Reg92c = rtw_read32(pDM_Odm->Adapter, rDPDT_control);
> -	pDM_SWAT_Table->PreAntenna = MAIN_ANT;
> -	pDM_SWAT_Table->CurAntenna = MAIN_ANT;
> -	pDM_SWAT_Table->SWAS_NoLink_State = 0;
> +	/* Dummy read rDPDT_control to preserve initialization hardware sequencing */
> +	rtw_read32(pDM_Odm->Adapter, rDPDT_control);

While it's nice to preserve this, how about testing on real hardware to
see if it too can be dropped?

thanks,

greg k-h