ath9k: Store the correct max TX power level

This patch fixes a bug where the max power level
was being calculated incorrectly.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath9k/eeprom.c

@@ -2615,6 +2615,21 @@ static int ath9k_hw_def_set_txpower(struct ath_hw *ah,
 	else
 		ah->regulatory.max_power_level = ratesArray[i];
 
+	switch(ar5416_get_ntxchains(ah->txchainmask)) {
+	case 1:
+		break;
+	case 2:
+		ah->regulatory.max_power_level += INCREASE_MAXPOW_BY_TWO_CHAIN;
+		break;
+	case 3:
+		ah->regulatory.max_power_level += INCREASE_MAXPOW_BY_THREE_CHAIN;
+		break;
+	default:
+		DPRINTF(ah->ah_sc, ATH_DBG_EEPROM,
+			"Invalid chainmask configuration\n");
+		break;
+	}
+
 	return 0;
 }
 

drivers/net/wireless/ath9k/eeprom.h

@@ -75,6 +75,9 @@
 #define SUB_NUM_CTL_MODES_AT_5G_40 2
 #define SUB_NUM_CTL_MODES_AT_2G_40 3
 
+#define INCREASE_MAXPOW_BY_TWO_CHAIN     6  /* 10*log10(2)*2 */
+#define INCREASE_MAXPOW_BY_THREE_CHAIN   10 /* 10*log10(3)*2 */
+
 #define AR_EEPROM_MAC(i)	(0x1d+(i))
 #define ATH9K_POW_SM(_r, _s)	(((_r) & 0x3f) << (_s))
 #define FREQ2FBIN(x, y)		((y) ? ((x) - 2300) : (((x) - 4800) / 5))