[PATCH 4.18 093/158] ath9k_hw: fix channel maximum power level test

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Felix Fietkau <nbd@xxxxxxxx>

[ Upstream commit 461d8a6bb9879b0e619752d040292e67aa06f1d2 ]

The tx power applied by set_txpower is limited by the CTL (conformance
test limit) entries in the EEPROM. These can change based on the user
configured regulatory domain.
Depending on the EEPROM data this can cause the tx power to become too
limited, if the original regdomain CTLs impose lower limits than the CTLs
of the user configured regdomain.

To fix this issue, set the initial channel limits without any CTL
restrictions and only apply the CTL at run time when setting the channel
and the real tx power.

Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/wireless/ath/ath9k/hw.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -2942,16 +2942,19 @@ void ath9k_hw_apply_txpower(struct ath_h
 	struct ath_regulatory *reg = ath9k_hw_regulatory(ah);
 	struct ieee80211_channel *channel;
 	int chan_pwr, new_pwr;
+	u16 ctl = NO_CTL;
 
 	if (!chan)
 		return;
 
+	if (!test)
+		ctl = ath9k_regd_get_ctl(reg, chan);
+
 	channel = chan->chan;
 	chan_pwr = min_t(int, channel->max_power * 2, MAX_RATE_POWER);
 	new_pwr = min_t(int, chan_pwr, reg->power_limit);
 
-	ah->eep_ops->set_txpower(ah, chan,
-				 ath9k_regd_get_ctl(reg, chan),
+	ah->eep_ops->set_txpower(ah, chan, ctl,
 				 get_antenna_gain(ah, chan), new_pwr, test);
 }