ath9k_hw: clean up tx power handling

The code for handling various restrictions concerning regulatory limits,
antenna gain, etc. is very convoluted and duplicated across various
EEPROM parsing implementations, making it hard to review.

This patch partially cleans up the mess by unifying regulatory limit
handling in one function and simplifying handling of antenna gain.
It also removes unused transmit power scaling arrays from the EEPROM code,
which belonged to an unimplemented API that isn't supposed to be in
the driver anyway.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 12 insertions, 31 deletions

diff --git a/drivers/net/wireless/ath/ath9k/eeprom_def.c b/drivers/net/wireless/ath/ath9k/eeprom_def.c
index eda681fc7ba6..e175e2078a39 100644
--- a/drivers/net/wireless/ath/ath9k/eeprom_def.c
+++ b/drivers/net/wireless/ath/ath9k/eeprom_def.c
@@ -400,6 +400,7 @@ static u32 ath9k_hw_def_get_eeprom(struct ath_hw *ah,
 	struct ar5416_eeprom_def *eep = &ah->eeprom.def;
 	struct modal_eep_header *pModal = eep->modalHeader;
 	struct base_eep_header *pBase = &eep->baseEepHeader;
+	int band = 0;
 
 	switch (param) {
 	case EEP_NFTHRESH_5:
@@ -467,6 +468,14 @@ static u32 ath9k_hw_def_get_eeprom(struct ath_hw *ah,
 			return pBase->pwr_table_offset;
 		else
 			return AR5416_PWR_TABLE_OFFSET_DB;
+	case EEP_ANTENNA_GAIN_2G:
+		band = 1;
+		/* fall through */
+	case EEP_ANTENNA_GAIN_5G:
+		return max_t(u8, max_t(u8,
+			pModal[band].antennaGainCh[0],
+			pModal[band].antennaGainCh[1]),
+			pModal[band].antennaGainCh[2]);
 	default:
 		return 0;
 	}
@@ -986,21 +995,15 @@ static void ath9k_hw_set_def_power_per_rate_table(struct ath_hw *ah,
 						  struct ath9k_channel *chan,
 						  int16_t *ratesArray,
 						  u16 cfgCtl,
-						  u16 AntennaReduction,
-						  u16 twiceMaxRegulatoryPower,
+						  u16 antenna_reduction,
 						  u16 powerLimit)
 {
 #define REDUCE_SCALED_POWER_BY_TWO_CHAIN     6  /* 10*log10(2)*2 */
 #define REDUCE_SCALED_POWER_BY_THREE_CHAIN   9 /* 10*log10(3)*2 */
 
-	struct ath_regulatory *regulatory = ath9k_hw_regulatory(ah);
 	struct ar5416_eeprom_def *pEepData = &ah->eeprom.def;
 	u16 twiceMaxEdgePower = MAX_RATE_POWER;
-	static const u16 tpScaleReductionTable[5] =
-		{ 0, 3, 6, 9, MAX_RATE_POWER };
-
 	int i;
-	int16_t twiceLargestAntenna;
 	struct cal_ctl_data *rep;
 	struct cal_target_power_leg targetPowerOfdm, targetPowerCck = {
 		0, { 0, 0, 0, 0}
@@ -1012,7 +1015,7 @@ static void ath9k_hw_set_def_power_per_rate_table(struct ath_hw *ah,
 	struct cal_target_power_ht targetPowerHt20, targetPowerHt40 = {
 		0, {0, 0, 0, 0}
 	};
-	u16 scaledPower = 0, minCtlPower, maxRegAllowedPower;
+	u16 scaledPower = 0, minCtlPower;
 	static const u16 ctlModesFor11a[] = {
 		CTL_11A, CTL_5GHT20, CTL_11A_EXT, CTL_5GHT40
 	};
@@ -1031,27 +1034,7 @@ static void ath9k_hw_set_def_power_per_rate_table(struct ath_hw *ah,
 
 	ath9k_hw_get_channel_centers(ah, chan, &centers);
 
-	twiceLargestAntenna = max(
-		pEepData->modalHeader
-			[IS_CHAN_2GHZ(chan)].antennaGainCh[0],
-		pEepData->modalHeader
-			[IS_CHAN_2GHZ(chan)].antennaGainCh[1]);
-
-	twiceLargestAntenna = max((u8)twiceLargestAntenna,
-				  pEepData->modalHeader
-				  [IS_CHAN_2GHZ(chan)].antennaGainCh[2]);
-
-	twiceLargestAntenna = (int16_t)min(AntennaReduction -
-					   twiceLargestAntenna, 0);
-
-	maxRegAllowedPower = twiceMaxRegulatoryPower + twiceLargestAntenna;
-
-	if (regulatory->tp_scale != ATH9K_TP_SCALE_MAX) {
-		maxRegAllowedPower -=
-			(tpScaleReductionTable[(regulatory->tp_scale)] * 2);
-	}
-
-	scaledPower = min(powerLimit, maxRegAllowedPower);
+	scaledPower = powerLimit - antenna_reduction;
 
 	switch (ar5416_get_ntxchains(tx_chainmask)) {
 	case 1:
@@ -1256,7 +1239,6 @@ static void ath9k_hw_def_set_txpower(struct ath_hw *ah,
 				    struct ath9k_channel *chan,
 				    u16 cfgCtl,
 				    u8 twiceAntennaReduction,
-				    u8 twiceMaxRegulatoryPower,
 				    u8 powerLimit, bool test)
 {
 #define RT_AR_DELTA(x) (ratesArray[x] - cck_ofdm_delta)
@@ -1278,7 +1260,6 @@ static void ath9k_hw_def_set_txpower(struct ath_hw *ah,
 	ath9k_hw_set_def_power_per_rate_table(ah, chan,
 					       &ratesArray[0], cfgCtl,
 					       twiceAntennaReduction,
-					       twiceMaxRegulatoryPower,
 					       powerLimit);
 
 	ath9k_hw_set_def_power_cal_table(ah, chan);