mac80211: ath10k: adjust tx power reduction for US regulatory domain

FCC allows maximum antenna gain of 6 dBi. 15.247(b)(4):

> (4) The conducted output power limit
> specified in paragraph (b) of this section
> is based on the use of antennas
> with directional gains that do not exceed
> 6 dBi. Except as shown in paragraph
> (c) of this section, if transmitting
> antennas of directional gain greater
> than 6 dBi are used, the conducted
> output power from the intentional radiator
> shall be reduced below the stated
> values in paragraphs (b)(1), (b)(2),
> and (b)(3) of this section, as appropriate,
> by the amount in dB that the
> directional gain of the antenna exceeds
> 6 dBi.

https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf

Signed-off-by: Sven Eckelmann <sven@narfation.org>
This commit is contained in:
Sven Eckelmann 2019-06-11 14:53:12 +02:00 committed by Christian Lamparter
parent f17529a122
commit 2f84bb1af2

View File

@ -0,0 +1,101 @@
From: Sven Eckelmann <seckelmann@datto.com>
Date: Wed, 28 Nov 2018 16:16:27 +0100
Subject: ath10k: adjust tx power reduction for US regulatory domain
FCC allows maximum antenna gain of 6 dBi. 15.247(b)(4):
> (4) The conducted output power limit
> specified in paragraph (b) of this section
> is based on the use of antennas
> with directional gains that do not exceed
> 6 dBi. Except as shown in paragraph
> (c) of this section, if transmitting
> antennas of directional gain greater
> than 6 dBi are used, the conducted
> output power from the intentional radiator
> shall be reduced below the stated
> values in paragraphs (b)(1), (b)(2),
> and (b)(3) of this section, as appropriate,
> by the amount in dB that the
> directional gain of the antenna exceeds
> 6 dBi.
https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf
Signed-off-by: Sven Eckelmann <seckelmann@datto.com>
Forwarded: no
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -988,6 +988,40 @@ static inline int ath10k_vdev_setup_sync
return 0;
}
+static u32 ath10k_get_max_antenna_gain(struct ath10k *ar,
+ u32 ch_max_antenna_gain)
+{
+ u32 max_antenna_gain;
+
+ if (ar->dfs_detector && ar->dfs_detector->region == NL80211_DFS_FCC) {
+ /* FCC allows maximum antenna gain of 6 dBi. 15.247(b)(4):
+ *
+ * > (4) The conducted output power limit
+ * > specified in paragraph (b) of this section
+ * > is based on the use of antennas
+ * > with directional gains that do not exceed
+ * > 6 dBi. Except as shown in paragraph
+ * > (c) of this section, if transmitting
+ * > antennas of directional gain greater
+ * > than 6 dBi are used, the conducted
+ * > output power from the intentional radiator
+ * > shall be reduced below the stated
+ * > values in paragraphs (b)(1), (b)(2),
+ * > and (b)(3) of this section, as appropriate,
+ * > by the amount in dB that the
+ * > directional gain of the antenna exceeds
+ * > 6 dBi.
+ *
+ * https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf
+ */
+ max_antenna_gain = 6;
+ } else {
+ max_antenna_gain = 0;
+ }
+
+ return max(ch_max_antenna_gain, max_antenna_gain);
+}
+
static int ath10k_monitor_vdev_start(struct ath10k *ar, int vdev_id)
{
struct cfg80211_chan_def *chandef = NULL;
@@ -1020,7 +1054,8 @@ 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;
+ arg.channel.max_antenna_gain = ath10k_get_max_antenna_gain(ar,
+ channel->max_antenna_gain);
reinit_completion(&ar->vdev_setup_done);
@@ -1462,7 +1497,8 @@ 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;
+ arg.channel.max_antenna_gain = ath10k_get_max_antenna_gain(ar,
+ chandef->chan->max_antenna_gain);
if (arvif->vdev_type == WMI_VDEV_TYPE_AP) {
arg.ssid = arvif->u.ap.ssid;
@@ -3139,7 +3175,8 @@ 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;
+ ch->max_antenna_gain = ath10k_get_max_antenna_gain(ar,
+ channel->max_antenna_gain);
ch->reg_class_id = 0; /* FIXME */
/* FIXME: why use only legacy modes, why not any