openwrtv4/package/mac80211/patches/542-ath9k_fix_half_quarter_sifs.patch

--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1007,31 +1007,35 @@ void ath9k_hw_init_global_settings(struc
 	if (IS_CHAN_HALF_RATE(chan)) {
 		eifs = 175;
 
-		if (!AR_SREV_9300_20_OR_LATER(ah))
+		if (!AR_SREV_9300_20_OR_LATER(ah)) {
 			rx_lat = 10;
-		else
+			sifstime = 8;
+		} else {
 			rx_lat *= 2;
+			sifstime = 32;
+		}
 
 		tx_lat *= 2;
 		if (IS_CHAN_A_FAST_CLOCK(ah, chan))
 			tx_lat += 11;
 
 		slottime = 13;
-		sifstime = 32;
 	} else if (IS_CHAN_QUARTER_RATE(chan)) {
 		eifs = 340;
 
-		if (!AR_SREV_9300_20_OR_LATER(ah))
+		if (!AR_SREV_9300_20_OR_LATER(ah)) {
 			rx_lat = 20;
-		else
+			sifstime = 8;
+		} else {
 			rx_lat = (rx_lat * 4) - 1;
+			sifstime = 64;
+		}
 
 		tx_lat *= 4;
 		if (IS_CHAN_A_FAST_CLOCK(ah, chan))
 		    tx_lat += 22;
 
 		slottime = 21;
-		sifstime = 64;
 	} else {
 		if (AR_SREV_9287(ah) && AR_SREV_9287_13_OR_LATER(ah)) {
 			eifs = AR_D_GBL_IFS_EIFS_ASYNC_FIFO;