ath9k: disable RIFS search for AR91xx based chips

@@ -1326,6 +1326,16 @@ static void ath9k_hw_override_ini(struct
 	 * Necessary to avoid issues on AR5416 2.0
 	 */
 	REG_WRITE(ah, 0x9800 + (651 << 2), 0x11);
+
+	/*
+	 * Disable RIFS search on some chips to avoid baseband
+	 * hang issues.
+	 */
+	if (AR_SREV_9100(ah) || AR_SREV_9160(ah)) {
+		val = REG_READ(ah, AR_PHY_HEAVY_CLIP_FACTOR_RIFS);
+		val &= ~AR_PHY_RIFS_INIT_DELAY;
+		REG_WRITE(ah, AR_PHY_HEAVY_CLIP_FACTOR_RIFS, val);
+	}
 }
 
 static u32 ath9k_hw_def_ini_fixup(struct ath_hw *ah,

@@ -384,6 +384,9 @@ bool ath9k_hw_set_rf_regs(struct ath_hw 
 
 #define AR_PHY_HEAVY_CLIP_ENABLE         0x99E0
 
+#define AR_PHY_HEAVY_CLIP_FACTOR_RIFS    0x99EC
+#define AR_PHY_RIFS_INIT_DELAY         0x03ff0000
+
 #define AR_PHY_M_SLEEP      0x99f0
 #define AR_PHY_REFCLKDLY    0x99f4
 #define AR_PHY_REFCLKPD     0x99f8