--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1846,7 +1846,8 @@ static void ath9k_set_power_sleep(struct
 	}
 
 	/* Clear Bit 14 of AR_WA after putting chip into Full Sleep mode. */
-	REG_WRITE(ah, AR_WA, ah->WARegVal & ~AR_WA_D3_L1_DISABLE);
+	if (AR_SREV_9300_20_OR_LATER(ah))
+		REG_WRITE(ah, AR_WA, ah->WARegVal & ~AR_WA_D3_L1_DISABLE);
 }
 
 /*
