package/kernel/mac80211/patches/ath/981-ath10k-adjust-tx-power-reduction-for-US-regulatory-d.patch

   1 From: Sven Eckelmann <seckelmann@datto.com>
   2 Date: Wed, 28 Nov 2018 16:16:27 +0100
   3 Subject: ath10k: adjust tx power reduction for US regulatory domain
   4
   5 FCC allows maximum antenna gain of 6 dBi. 15.247(b)(4):
   6
   7 > (4) The conducted output power limit
   8 > specified in paragraph (b) of this section
   9 > is based on the use of antennas
  10 > with directional gains that do not exceed
  11 > 6 dBi. Except as shown in paragraph
  12 > (c) of this section, if transmitting
  13 > antennas of directional gain greater
  14 > than 6 dBi are used, the conducted
  15 > output power from the intentional radiator
  16 > shall be reduced below the stated
  17 > values in paragraphs (b)(1), (b)(2),
  18 > and (b)(3) of this section, as appropriate,
  19 > by the amount in dB that the
  20 > directional gain of the antenna exceeds
  21 > 6 dBi.
  22
  23 https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf
  24
  25 Signed-off-by: Sven Eckelmann <seckelmann@datto.com>
  26
  27 Forwarded: no
  28
  29 --- a/drivers/net/wireless/ath/ath10k/mac.c
  30 +++ b/drivers/net/wireless/ath/ath10k/mac.c
  31 @@ -1009,6 +1009,40 @@ static inline int ath10k_vdev_setup_sync
  32         return ar->last_wmi_vdev_start_status;
  33  }
  34
  35 +static u32 ath10k_get_max_antenna_gain(struct ath10k *ar,
  36 +                                      u32 ch_max_antenna_gain)
  37 +{
  38 +       u32 max_antenna_gain;
  39 +
  40 +       if (ar->dfs_detector && ar->dfs_detector->region == NL80211_DFS_FCC) {
  41 +               /* FCC allows maximum antenna gain of 6 dBi. 15.247(b)(4):
  42 +                *
  43 +                * > (4) The conducted output power limit
  44 +                * > specified in paragraph (b) of this section
  45 +                * > is based on the use of antennas
  46 +                * > with directional gains that do not exceed
  47 +                * > 6 dBi. Except as shown in paragraph
  48 +                * > (c) of this section, if transmitting
  49 +                * > antennas of directional gain greater
  50 +                * > than 6 dBi are used, the conducted
  51 +                * > output power from the intentional radiator
  52 +                * > shall be reduced below the stated
  53 +                * > values in paragraphs (b)(1), (b)(2),
  54 +                * > and (b)(3) of this section, as appropriate,
  55 +                * > by the amount in dB that the
  56 +                * > directional gain of the antenna exceeds
  57 +                * > 6 dBi.
  58 +                *
  59 +                * https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf
  60 +                */
  61 +               max_antenna_gain = 6;
  62 +       } else {
  63 +               max_antenna_gain = 0;
  64 +       }
  65 +
  66 +       return max(ch_max_antenna_gain, max_antenna_gain);
  67 +}
  68 +
  69  static int ath10k_monitor_vdev_start(struct ath10k *ar, int vdev_id)
  70  {
  71         struct cfg80211_chan_def *chandef = NULL;
  72 @@ -1041,7 +1075,8 @@ static int ath10k_monitor_vdev_start(str
  73         arg.channel.min_power = 0;
  74         arg.channel.max_power = channel->max_power * 2;
  75         arg.channel.max_reg_power = channel->max_reg_power * 2;
  76 -       arg.channel.max_antenna_gain = channel->max_antenna_gain;
  77 +       arg.channel.max_antenna_gain = ath10k_get_max_antenna_gain(ar,
  78 +                                               channel->max_antenna_gain);
  79
  80         reinit_completion(&ar->vdev_setup_done);
  81         reinit_completion(&ar->vdev_delete_done);
  82 @@ -1487,7 +1522,8 @@ static int ath10k_vdev_start_restart(str
  83         arg.channel.min_power = 0;
  84         arg.channel.max_power = chandef->chan->max_power * 2;
  85         arg.channel.max_reg_power = chandef->chan->max_reg_power * 2;
  86 -       arg.channel.max_antenna_gain = chandef->chan->max_antenna_gain;
  87 +       arg.channel.max_antenna_gain = ath10k_get_max_antenna_gain(ar,
  88 +                                       chandef->chan->max_antenna_gain);
  89
  90         if (arvif->vdev_type == WMI_VDEV_TYPE_AP) {
  91                 arg.ssid = arvif->u.ap.ssid;
  92 @@ -3168,7 +3204,8 @@ static int ath10k_update_channel_list(st
  93                         ch->min_power = 0;
  94                         ch->max_power = channel->max_power * 2;
  95                         ch->max_reg_power = channel->max_reg_power * 2;
  96 -                       ch->max_antenna_gain = channel->max_antenna_gain;
  97 +                       ch->max_antenna_gain = ath10k_get_max_antenna_gain(ar,
  98 +                                               channel->max_antenna_gain);
  99                         ch->reg_class_id = 0; /* FIXME */
 100
 101                         /* FIXME: why use only legacy modes, why not any