ath9k: avoid accessing MRC registers on single-chain devices

They are not implemented, and accessing them might trigger errors

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

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_phy.c b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
index 39c3730..18a5aa4 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ar9003_phy.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
@@ -1172,6 +1172,10 @@ skip_ws_det:
                 * is_on == 0 means MRC CCK is OFF (more noise imm)
                 */
                bool is_on = param ? 1 : 0;
+
+               if (ah->caps.rx_chainmask == 1)
+                       break;
+
                REG_RMW_FIELD(ah, AR_PHY_MRC_CCK_CTRL,
                              AR_PHY_MRC_CCK_ENABLE, is_on);
                REG_RMW_FIELD(ah, AR_PHY_MRC_CCK_CTRL,