linux-kernel - [PATCH AUTOSEL 5.4 122/130] mac80211: ignore country element TX power on 6 GHz

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Date:   Tue, 22 Dec 2020 21:18:05 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Johannes Berg <johannes.berg@...el.com>,
        Luca Coelho <luciano.coelho@...el.com>,
        Sasha Levin <sashal@...nel.org>,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 122/130] mac80211: ignore country element TX power on 6 GHz

From: Johannes Berg <johannes.berg@...el.com>

[ Upstream commit 2dedfe1dbdf27ac344584ed03c3876c85d2779fb ]

Updates to the 802.11ax draft are coming that deprecate the
country element in favour of the transmit power envelope
element, and make the maximum transmit power level field in
the triplets reserved, so if we parse them we'd use 0 dBm
transmit power.

Follow suit and completely ignore the element on 6 GHz for
purposes of determining TX power.

Signed-off-by: Johannes Berg <johannes.berg@...el.com>
Signed-off-by: Luca Coelho <luciano.coelho@...el.com>
Link: https://lore.kernel.org/r/iwlwifi.20201206145305.9abf9f6b4f88.Icb6e52af586edcc74f1f0360e8f6fc9ef2bfe8f5@changeid
Signed-off-by: Johannes Berg <johannes.berg@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 net/mac80211/mlme.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 236ddc6b891c2..ba1e5cac32adb 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1487,6 +1487,15 @@ ieee80211_find_80211h_pwr_constr(struct ieee80211_sub_if_data *sdata,
 	case NL80211_BAND_5GHZ:
 		chan_increment = 4;
 		break;
+	case NL80211_BAND_6GHZ:
+		/*
+		 * In the 6 GHz band, the "maximum transmit power level"
+		 * field in the triplets is reserved, and thus will be
+		 * zero and we shouldn't use it to control TX power.
+		 * The actual TX power will be given in the transmit
+		 * power envelope element instead.
+		 */
+		return false;
 	}
 
 	/* find channel */
-- 
2.27.0