From: Sven Eckelmann 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 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; @@ -3143,7 +3179,8 @@ 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