ath9k: Fix TX99 support

The patch 300-ath9k-force-rx_clear-when-disabling-rx.patch broke TX99 support
in ath9k. Fix the patch by only applying rx_clear if TX99 mode is not used.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>

package/kernel/mac80211/patches/300-ath9k-force-rx_clear-when-disabling-rx.patch

@@ -3,15 +3,16 @@ Date: Sun, 7 Jun 2015 13:53:35 +0200
 Subject: [PATCH] ath9k: force rx_clear when disabling rx
 
 This makes stopping Rx more reliable and should reduce the frequency of
-Rx related DMA stop warnings
+Rx related DMA stop warnings. Don't use rx_clear in TX99 mode.
 
 Cc: stable@vger.kernel.org
 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
 ---
 
 --- a/drivers/net/wireless/ath/ath9k/mac.c
 +++ b/drivers/net/wireless/ath/ath9k/mac.c
-@@ -677,13 +677,15 @@ void ath9k_hw_startpcureceive(struct ath
+@@ -677,13 +677,18 @@ void ath9k_hw_startpcureceive(struct ath
  
  	ath9k_ani_reset(ah, is_scanning);
  
@@ -24,8 +25,11 @@ Signed-off-by: Felix Fietkau <nbd@openwrt.org>
  void ath9k_hw_abortpcurecv(struct ath_hw *ah)
  {
 -	REG_SET_BIT(ah, AR_DIAG_SW, AR_DIAG_RX_ABORT | AR_DIAG_RX_DIS);
-+	REG_SET_BIT(ah, AR_DIAG_SW,
-+		    AR_DIAG_RX_DIS | AR_DIAG_RX_ABORT | AR_DIAG_FORCE_RX_CLEAR);
++	u32 reg = AR_DIAG_RX_DIS | AR_DIAG_RX_ABORT;
++
++	if (!config_enabled(CPTCFG_ATH9K_TX99))
++		reg |= AR_DIAG_FORCE_RX_CLEAR;
++	REG_SET_BIT(ah, AR_DIAG_SW, reg);
  
  	ath9k_hw_disable_mib_counters(ah);
  }