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From:   Peter Oh <peter.oh@eero.com>
Date:   Wed, 11 Sep 2019 09:28:51 -0700
Message-ID: <CALhWmc2qPf-qCrx3JdejkOi-SQnURnehF43byCk-nZtCDWoJ3Q@mail.gmail.com>
Subject: Re: [PATCH] Can't scan on ETSI domains when operating ch is DFS
To:     Aaron Komisar <aaron.komisar@tandemg.com>
Cc:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
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On Wed, Sep 11, 2019 at 12:59 AM Aaron Komisar
<aaron.komisar@tandemg.com> wrote:
>
> In non-ETSI reg domains scan is blocked when operating channel is a DFS ch.
> For ETSI domains, however, once DFS channel is marked as available afer
> the CAC, this channel will remain available even after leaving this channel.
> Therefore a new CAC will not be required when scan is done.
>
> In cfg80211 scan is not blocked for ETSI reg domains.
> This patch enables scan in mac80211 as well when operating channel is a radar
> channel for ETSI reg domains.
>
> Signed-off-by: Aaron Komisar <aaron.komisar@tandemg.com>
> ---
>  include/net/cfg80211.h | 8 ++++++++
>  net/mac80211/scan.c    | 6 ++++--
>  net/wireless/reg.c     | 1 +
>  net/wireless/reg.h     | 8 --------
>  4 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index 5253e7f667bd..5349898ed3e6 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -5546,6 +5546,14 @@ const struct ieee80211_reg_rule *freq_reg_info(struct wiphy *wiphy,
>  const char *reg_initiator_name(enum nl80211_reg_initiator initiator);
>
>  /**
> + * regulatory_pre_cac_allowed - if pre-CAC allowed in the current dfs domain
> + * @wiphy: wiphy for which pre-CAC capability is checked.
> +
> + * Pre-CAC is allowed only in ETSI domain.
> + */
> +bool regulatory_pre_cac_allowed(struct wiphy *wiphy);
> +
> +/**
>   * DOC: Internal regulatory db functions
>   *
>   */
> diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
> index adf94ba1ed77..812ff820844b 100644
> --- a/net/mac80211/scan.c
> +++ b/net/mac80211/scan.c
> @@ -523,7 +523,8 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local,
>  static bool ieee80211_can_scan(struct ieee80211_local *local,
>                                struct ieee80211_sub_if_data *sdata)
>  {
> -       if (ieee80211_is_radar_required(local))
> +       if (ieee80211_is_radar_required(local) &&
> +           !regulatory_pre_cac_allowed(local->hw.wiphy))
"pre-CAC allowed" doesn't mean that you can use the channel without CAC is done.
>                 return false;
>
>         if (!list_empty(&local->roc_list))
> @@ -630,7 +631,8 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
>
>         lockdep_assert_held(&local->mtx);
>
> -       if (local->scan_req || ieee80211_is_radar_required(local))
> +       if (local->scan_req || (ieee80211_is_radar_required(local) &&
> +           !regulatory_pre_cac_allowed(local->hw.wiphy)))
>                 return -EBUSY;
>
>         if (!ieee80211_can_scan(local, sdata)) {
> diff --git a/net/wireless/reg.c b/net/wireless/reg.c
> index 5311d0ae2454..50d3242c4985 100644
> --- a/net/wireless/reg.c
> +++ b/net/wireless/reg.c
> @@ -3883,6 +3883,7 @@ bool regulatory_pre_cac_allowed(struct wiphy *wiphy)
>
>         return pre_cac_allowed;
>  }
> +EXPORT_SYMBOL(regulatory_pre_cac_allowed);
>
>  void regulatory_propagate_dfs_state(struct wiphy *wiphy,
>                                     struct cfg80211_chan_def *chandef,
> diff --git a/net/wireless/reg.h b/net/wireless/reg.h
> index 504133d76de4..dc8f689bd469 100644
> --- a/net/wireless/reg.h
> +++ b/net/wireless/reg.h
> @@ -156,14 +156,6 @@ bool regulatory_indoor_allowed(void);
>  #define REG_PRE_CAC_EXPIRY_GRACE_MS 2000
>
>  /**
> - * regulatory_pre_cac_allowed - if pre-CAC allowed in the current dfs domain
> - * @wiphy: wiphy for which pre-CAC capability is checked.
> -
> - * Pre-CAC is allowed only in ETSI domain.
> - */
> -bool regulatory_pre_cac_allowed(struct wiphy *wiphy);
> -
> -/**
>   * regulatory_propagate_dfs_state - Propagate DFS channel state to other wiphys
>   * @wiphy - wiphy on which radar is detected and the event will be propagated
>   *     to other available wiphys having the same DFS domain
> --
> 2.11.0
>