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Reply-To: yunhanw@nestlabs.com
From:   Yunhan Wang <yunhanw@nestlabs.com>
Date:   Thu, 13 Dec 2018 13:38:19 -0800
Message-ID: <CALvjcs9iYvgxN4YWzirw_Fxx30cDKYCyir+ZmpgsuBvcTJN+Zg@mail.gmail.com>
Subject: Re: BLE advertisement re-enabling after ble connection goes away
To:     Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        linux-bluetooth@vger.kernel.org,
        Marcel Holtmann <marcel@holtmann.org>,
        Martin Turon <mturon@google.com>
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+Martin

Hi, Luiz and Marcel

When I take a look at the bluetooth code, it seems it is re-enabling
ble advertisement after ble connection goes away. Any idea?

https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git/tree/net/bluetooth/hci_event.c#n2634
https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git/tree/net/bluetooth/hci_event.c#n2712
https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git/tree/net/bluetooth/hci_request.c#n1386
https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git/tree/net/bluetooth/hci_request.c#n1734

Thanks
Best wishes
Yunhan
On Wed, Dec 5, 2018 at 6:54 PM Yunhan Wang <yunhanw@nestlabs.com> wrote:
>
> Hi, Luiz and Marcel
>
> May I have a question on ble behavior on BLE re-advertisement?
>
> According to Bluetooth spec Vol. 3 (the host volume), 9.2.4.2, "The
> device shall remain in general discoverable mode until a connection is
> established or the Host terminates the mode."
>
> There is no description on re-enabling the advertising "after"
> disconnection, so the responsibility for re-enabling the advertising
> is bluez or kernel or application code? In other words, does kernel or
> bluez or application would re-enable the ble advertisement after ble
> disconnection happens?
>
> Thanks
> Best wishes
> Yunhan.