From: Sven Eckelmann <seckelmann@datto.com>
Date: Tue, 11 Jun 2019 13:58:35 +0200
Subject: ath10k: fix max antenna gain unit

Most of the txpower for the ath10k firmware is stored as twicepower (0.5 dB
steps). This isn't the case for max_antenna_gain - which is still expected
by the firmware as dB.

The firmware is converting it from dB to the internal (twicepower)
representation when it calculates the limits of a channel. This can be seen
in tpc_stats when configuring "12" as max_antenna_gain. Instead of the
expected 12 (6 dB), the tpc_stats shows 24 (12 dB).

Tested on QCA9888 and IPQ4019 with firmware 10.4-3.5.3-00057.

Fixes: 02256930d9b8 ("ath10k: use proper tx power unit")
Signed-off-by: Sven Eckelmann <seckelmann@datto.com>

Forwarded: https://patchwork.kernel.org/patch/10986723/

--- a/ath10k-4.19/mac.c
+++ b/ath10k-4.19/mac.c
@@ -1185,7 +1185,7 @@ static int ath10k_monitor_vdev_start(str
 	arg.channel.min_power = 0;
 	arg.channel.max_power = channel->max_power * 2;
 	arg.channel.max_reg_power = channel->max_reg_power * 2;
-	arg.channel.max_antenna_gain = channel->max_antenna_gain * 2;
+	arg.channel.max_antenna_gain = channel->max_antenna_gain;
 
 	reinit_completion(&ar->vdev_setup_done);
 
@@ -1627,7 +1627,7 @@ static int ath10k_vdev_start_restart(str
 	arg.channel.min_power = 0;
 	arg.channel.max_power = chandef->chan->max_power * 2;
 	arg.channel.max_reg_power = chandef->chan->max_reg_power * 2;
-	arg.channel.max_antenna_gain = chandef->chan->max_antenna_gain * 2;
+	arg.channel.max_antenna_gain = chandef->chan->max_antenna_gain;
 
 	/* CT Firmware can support 32+ VDEVS, but can only support
 	 * beacon-ing devs with dev ids 0 - 31 due to firmware limitations.
@@ -3799,7 +3799,7 @@ static int ath10k_update_channel_list(st
 			ch->min_power = 0;
 			ch->max_power = channel->max_power * 2;
 			ch->max_reg_power = channel->max_reg_power * 2;
-			ch->max_antenna_gain = channel->max_antenna_gain * 2;
+			ch->max_antenna_gain = channel->max_antenna_gain;
 			ch->reg_class_id = 0; /* FIXME */
 
 			/* FIXME: why use only legacy modes, why not any