ath9k_htc: Add support for power save.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 81965b2..88f8bfd 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -3245,8 +3245,10 @@
 		pCap->hw_caps |= ATH9K_HW_CAP_RFSILENT;
 	}
 #endif
-
-	pCap->hw_caps &= ~ATH9K_HW_CAP_AUTOSLEEP;
+	if (AR_SREV_9271(ah))
+		pCap->hw_caps |= ATH9K_HW_CAP_AUTOSLEEP;
+	else
+		pCap->hw_caps &= ~ATH9K_HW_CAP_AUTOSLEEP;
 
 	if (AR_SREV_9280(ah) || AR_SREV_9285(ah))
 		pCap->hw_caps &= ~ATH9K_HW_CAP_4KB_SPLITTRANS;