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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Tue, 27 Oct 2020 15:05:12 -0700
Message-ID: <CABBYNZ+OdP5dyG8BsEZNu5_6oiOoeF=piSXNnyzfv+6uO0QjiQ@mail.gmail.com>
Subject: Re: [Bluez PATCH v4 08/10] advertising: Expose SupportedCapabilities
 for advertising
To:     Daniel Winkler <danielwinkler@google.com>
Cc:     Luiz Augusto Von Dentz <luiz.von.dentz@intel.com>,
        "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>,
        ChromeOS Bluetooth Upstreaming 
        <chromeos-bluetooth-upstreaming@chromium.org>,
        Sonny Sasaka <sonnysasaka@chromium.org>,
        Alain Michaud <alainm@chromium.org>
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Precedence: bulk

Hi Daniel,

On Thu, Oct 1, 2020 at 4:07 PM Daniel Winkler <danielwinkler@google.com> wrote:
>
> To help our advertising clients understand the device capabilities, this
> patch adds a SupportedCapabilities dbus endpoint for the advertising
> manager. The primary reason behind this is to provide the valid LE tx
> power range the controller supports (populated if controller supports
> BT5), so a client can know the valid power range before requesting a tx
> power for their advertisement.
>
> I also thought it would be useful to indicate the max advertising data
> length and scan response length in this endpoint, since some clients
> will find it useful to set their advertising data (currently
> experimental feature) or scan response data (possible future feature)
> directly.
>
> This patch has been tested on Hatch (BT5 support) and Kukui (No BT5
> support) chromebooks to verify that the dbus endpoint contains the
> correct data.
>
> Reviewed-by: Sonny Sasaka <sonnysasaka@chromium.org>
> Reviewed-by: Alain Michaud <alainm@chromium.org>
> ---
>
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
>  src/advertising.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
>
> diff --git a/src/advertising.c b/src/advertising.c
> index 41d0658c8..f76831594 100644
> --- a/src/advertising.c
> +++ b/src/advertising.c
> @@ -1619,12 +1619,46 @@ static gboolean get_supported_secondary(const GDBusPropertyTable *property,
>         return TRUE;
>  }
>
> +static gboolean get_supported_cap(const GDBusPropertyTable *property,
> +                                       DBusMessageIter *iter, void *data)
> +{
> +       struct btd_adv_manager *manager = data;
> +       DBusMessageIter dict;
> +       int16_t min_tx_power = manager->min_tx_power;
> +       int16_t max_tx_power = manager->max_tx_power;
> +
> +       dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY,
> +                                       DBUS_DICT_ENTRY_BEGIN_CHAR_AS_STRING
> +                                       DBUS_TYPE_STRING_AS_STRING
> +                                       DBUS_TYPE_VARIANT_AS_STRING
> +                                       DBUS_DICT_ENTRY_END_CHAR_AS_STRING,
> +                                       &dict);
> +
> +       if (min_tx_power != ADV_TX_POWER_NO_PREFERENCE)
> +               dict_append_entry(&dict, "MinTxPower", DBUS_TYPE_INT16,
> +                               &min_tx_power);
> +
> +       if (max_tx_power != ADV_TX_POWER_NO_PREFERENCE)
> +               dict_append_entry(&dict, "MaxTxPower", DBUS_TYPE_INT16,
> +                               &max_tx_power);
> +
> +       dict_append_entry(&dict, "MaxAdvLen", DBUS_TYPE_BYTE,
> +                       &manager->max_adv_len);
> +       dict_append_entry(&dict, "MaxScnRspLen", DBUS_TYPE_BYTE,
> +                       &manager->max_scan_rsp_len);
> +
> +       dbus_message_iter_close_container(iter, &dict);
> +
> +       return TRUE;
> +}
> +
>  static const GDBusPropertyTable properties[] = {
>         { "ActiveInstances", "y", get_active_instances, NULL, NULL },
>         { "SupportedInstances", "y", get_instances, NULL, NULL },
>         { "SupportedIncludes", "as", get_supported_includes, NULL, NULL },
>         { "SupportedSecondaryChannels", "as", get_supported_secondary, NULL,
>                                                         secondary_exits },
> +       { "SupportedCapabilities", "a{sv}", get_supported_cap, NULL, NULL},

Lets mark this as experimental for now.

>         { }
>  };
>
> --
> 2.28.0.709.gb0816b6eb0-goog
>


-- 
Luiz Augusto von Dentz