ath9k: disable TPC support for now until bugs have been found and fixed

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44768 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/kernel/mac80211/patches/309-ath9k-disable-TPC-support-again-for-now.patch

+From: Felix Fietkau <nbd@openwrt.org>
+Date: Sun, 15 Mar 2015 08:02:37 +0100
+Subject: [PATCH] ath9k: disable TPC support again (for now)
+
+TPC support has been observed to cause some tx power fluctuations on
+some devices with at least AR934x and AR938x chips.
+Disable it for now until the bugs have been found and fixed
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/wireless/ath/ath9k/hw.c
++++ b/drivers/net/wireless/ath/ath9k/hw.c
+@@ -424,7 +424,7 @@ static void ath9k_hw_init_defaults(struc
+ 	ah->power_mode = ATH9K_PM_UNDEFINED;
+ 	ah->htc_reset_init = true;
+ 
+-	ah->tpc_enabled = true;
++	ah->tpc_enabled = false;
+ 
+ 	ah->ani_function = ATH9K_ANI_ALL;
+ 	if (!AR_SREV_9300_20_OR_LATER(ah))