ath9k: Fix eifs/usec timeout for AR9287 v1.3+

For AR9287 v1.3+ chips, MAC runs at 117MHz. But the initvals
IFS parameters are loaded based on 44/88MHz clockrate. So
eifs/usec from ini should not be used for AR9287 v1.3+.
The mentioned values are tested on 2 chain HT40 mode.
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -997,8 +997,14 @@ void ath9k_hw_init_global_settings(struct ath_hw *ah)
 		slottime = 21;
 		sifstime = 64;
 	} else {
-		eifs = REG_READ(ah, AR_D_GBL_IFS_EIFS)/common->clockrate;
-		reg = REG_READ(ah, AR_USEC);
+		if (AR_SREV_9287(ah) && AR_SREV_9287_13_OR_LATER(ah)) {
+			eifs = AR_D_GBL_IFS_EIFS_ASYNC_FIFO;
+			reg = AR_USEC_ASYNC_FIFO;
+		} else {
+			eifs = REG_READ(ah, AR_D_GBL_IFS_EIFS)/
+				common->clockrate;
+			reg = REG_READ(ah, AR_USEC);
+		}
 		rx_lat = MS(reg, AR_USEC_RX_LAT);
 		tx_lat = MS(reg, AR_USEC_TX_LAT);
 

drivers/net/wireless/ath/ath9k/reg.h

@@ -619,6 +619,7 @@
 #define AR_D_GBL_IFS_EIFS         0x10b0
 #define AR_D_GBL_IFS_EIFS_M       0x0000FFFF
 #define AR_D_GBL_IFS_EIFS_RESV0   0xFFFF0000
+#define AR_D_GBL_IFS_EIFS_ASYNC_FIFO 363
 
 #define AR_D_GBL_IFS_MISC        0x10f0
 #define AR_D_GBL_IFS_MISC_LFSR_SLICE_SEL        0x00000007
@@ -1503,6 +1504,7 @@ enum {
 #define AR_USEC_TX_LAT_S     14
 #define AR_USEC_RX_LAT       0x1F800000
 #define AR_USEC_RX_LAT_S     23
+#define AR_USEC_ASYNC_FIFO   0x12E00074
 
 #define AR_RESET_TSF        0x8020
 #define AR_RESET_TSF_ONCE   0x01000000