ath9k_hw: fix chain swap setting when setting rx chainmask to 5

commit 959f049d upstream.

commit 24171dd9 upstream.

Chain swapping should only be enabled when the EEPROM chainmask is set to 5,
regardless of what the runtime chainmask is.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: keep the special case for AR_SREV_9462 here]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/wireless/ath/ath9k/ar9003_phy.c

@@ -545,33 +545,20 @@ static void ar9003_hw_init_bb(struct ath_hw *ah,
 
 void ar9003_hw_set_chain_masks(struct ath_hw *ah, u8 rx, u8 tx)
 {
-	switch (rx) {
-	case 0x5:
+	if (ah->caps.tx_chainmask == 5 || ah->caps.rx_chainmask == 5)
 		REG_SET_BIT(ah, AR_PHY_ANALOG_SWAP,
 			    AR_PHY_SWAP_ALT_CHAIN);
-	case 0x3:
-	case 0x1:
-	case 0x2:
-	case 0x7:
+
 	REG_WRITE(ah, AR_PHY_RX_CHAINMASK, rx);
 	REG_WRITE(ah, AR_PHY_CAL_CHAINMASK, rx);
-		break;
-	default:
-		break;
-	}
 
 	if ((ah->caps.hw_caps & ATH9K_HW_CAP_APM) && (tx == 0x7))
-		REG_WRITE(ah, AR_SELFGEN_MASK, 0x3);
+		tx = 3;
 	else if (AR_SREV_9462(ah))
 		/* xxx only when MCI support is enabled */
-		REG_WRITE(ah, AR_SELFGEN_MASK, 0x3);
-	else
-		REG_WRITE(ah, AR_SELFGEN_MASK, tx);
+		tx = 3;
 
-	if (tx == 0x5) {
-		REG_SET_BIT(ah, AR_PHY_ANALOG_SWAP,
-			    AR_PHY_SWAP_ALT_CHAIN);
-	}
+	REG_WRITE(ah, AR_SELFGEN_MASK, tx);
 }
 
 /*