--- /dev/null
+From: Felix Fietkau <nbd@nbd.name>
+Date: Wed, 19 Jul 2017 08:49:31 +0200
+Subject: [PATCH] ath9k: adjust tx power reduction for US regulatory domain
+
+FCC regulatory rules allow for up to 3 dBi antenna gain. Account for
+this in the EEPROM based tx power reduction code.
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/drivers/net/wireless/ath/ath9k/hw.c
++++ b/drivers/net/wireless/ath/ath9k/hw.c
+@@ -2954,6 +2954,10 @@ void ath9k_hw_apply_txpower(struct ath_h
+ if (ant_gain > max_gain)
+ ant_reduction = ant_gain - max_gain;
+
++ /* FCC allows maximum antenna gain of 3 dBi */
++ if (reg->region == NL80211_DFS_FCC)
++ ant_reduction = min_t(int, ant_reduction - 6, 0);
++
+ ah->eep_ops->set_txpower(ah, chan, ctl, ant_reduction, new_pwr, test);
+ }
+