Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,T_MIXED_ES,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB2CCC65BAE for ; Fri, 14 Dec 2018 02:06:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 705D220879 for ; Fri, 14 Dec 2018 02:06:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nestlabs.com header.i=@nestlabs.com header.b="SEAGXT1i" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 705D220879 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nestlabs.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-bluetooth-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728811AbeLNCGf (ORCPT ); Thu, 13 Dec 2018 21:06:35 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:53502 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728596AbeLNCGe (ORCPT ); Thu, 13 Dec 2018 21:06:34 -0500 Received: by mail-it1-f196.google.com with SMTP id g85so6821407ita.3 for ; Thu, 13 Dec 2018 18:06:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nestlabs.com; s=google; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc:content-transfer-encoding; bh=FOp8BCzmS1cZ1jZTllPz62tuGB6nDZj+BhCPx/tA05Q=; b=SEAGXT1i6ecxIVh5qe7F1HkZ7MLhKID7AZ1fMexwamvblJkKxyyzC7c7W8Dut6aKZp xXgNx4TUIDjc23qs4xNjJeUwYSYiXZTRyOXtyR0dSm6A3euSaceHc+qqO1SODI/JJsHw GT4OdW+15uD+gMrdXN3bJSd8f3eVu0YdtnN6A= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc:content-transfer-encoding; bh=FOp8BCzmS1cZ1jZTllPz62tuGB6nDZj+BhCPx/tA05Q=; b=DQTCGsoA7OHc4VsNliIdLAIQf8VvvFzzDgNdHqOnL/XT6P6cgMjsYWkh8ip2OguTE5 ZqWY3dr6HDWgkhYAHq29i/LrjOwQIaX1h1PjX60AwYk7R5rVUln85AKdK5qfuROkshZW ePtv70BMEjsRZhhtlBEmuRhLmdqklSSKWdUJnH7NeybnGtl6aCPNpb1txs2CxDI3OLyo LRFyB3y3n40hzIwC+YPA20a4cO5+peOeWnCb0CpzXC3mzTmxH7tcM0eyR//f64XovJwp FKbggRVQF5HoimGbQuh+uMtxoGqmqHhJX/d5j0D3kF0hdgs4A0DVw+GchxkfBvL49zFE jbOA== X-Gm-Message-State: AA+aEWYL2Ycs1B9BV1b9KnDhMRg9bDcMhSpBUrgehxpt3gYSxhdoMLWV pctQwCk/+aMEdoFiX9rH4o2cjvH7DzaQSwHCKdelUg== X-Google-Smtp-Source: AFSGD/UEeAHvcLvJoRyF8Ie02yvtFx+VIi3srYNfXBRll+z8IMfdpE52gww0OwvkD84P//NkZUiYmCahU85jwacKOVs= X-Received: by 2002:a24:b8c6:: with SMTP id m189mr1587909ite.72.1544753193254; Thu, 13 Dec 2018 18:06:33 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Reply-To: yunhanw@nestlabs.com From: Yunhan Wang Date: Thu, 13 Dec 2018 18:06:22 -0800 Message-ID: Subject: Re: BLE advertisement re-enabling after ble connection goes away To: Luiz Augusto von Dentz Cc: Martin Turon , Marcel Holtmann , linux-bluetooth@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org Hi, Luiz Thanks for your reply. A little bit confused here. There is no code in bluez that directly re-enable advertisement, if there is, could you show the code location in bluez? Bluetooth in kernel is responsible for re-enabling advertisement? The responsibility for re-enabling the advertising is kernel instead of bluez and user application code. Thanks Best wishes Yunhan On Thu, Dec 13, 2018 at 5:21 PM Luiz Augusto von Dentz wrote: > > Hi Yunhan, > > You already answered your question, it is reenabled by > hci_req_reenable_advertising > > > On Fri, Dec 14, 2018 at 1:13 AM Yunhan Wang wrote: > > > > Hi, Luiz > > > > Rephrasing a little bit.. > > > > From what you describes, it seems Bluez is taking the responsibility > > to reenable the advertisement in peripheral side after the previous > > ble connection goes > > away. > > > > When I did local test, the ble peripheral is using bluez, I create > > gatt server and ble advertisment using Bluez DBus API, when remote > > connection in central disconnects, I see kernel in Bluez in peripheral > > side do receive > > HCI_EV_DISCONN_COMPLETE event, and trigger > > hci_req_reenable_advertising. > > > > Maybe you can share the code location where Bluez is reenabling the > > advertisement after ble connection goes away? > > > > Thanks > > Best wishes > > On Thu, Dec 13, 2018 at 3:10 PM Yunhan Wang wrot= e: > > > > > > Hi, Luiz > > > > > > From what you describes, it seems Bluez is taking the responsibility > > > to reenable the advertisement after the previous ble connection goes > > > away. > > > > > > When I did local test, the ble peripheral is using bluez, I create > > > gatt server and ble advertisment using Bluez DBus API, when remote > > > connection in central disconnects, I see kernel in Bluez do receive > > > HCI_EV_DISCONN_COMPLETE event, and trigger > > > hci_req_reenable_advertising. > > > > > > Maybe you can share the code location where Bluez is reenabling the > > > advertisement after ble connection goes away? > > > > > > Thanks > > > Best wishes > > > Yunhan > > > > > > On Thu, Dec 13, 2018 at 2:30 PM Martin Turon wrot= e: > > > > > > > > Hi Luiz, > > > > > > > > Is this behavior also expected on raw hci sockets? Because my obse= rvation is that when working with raw hci over such sockets, auto-reenable = does not occur. > > > > > > > > #define BTPROTO_HCI 1 > > > > #define HCI_CHANNEL_USER 1 > > > > > > > > struct sockaddr_hci shci; > > > > shci.hci_family =3D AF_BLUETOOTH; > > > > shci.hci_dev =3D s_ble_hci_device; > > > > shci.hci_channel =3D HCI_CHANNEL_USER; > > > > > > > > s =3D socket(PF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); > > > > rc =3D bind(s, (struct sockaddr *)&shci, sizeof(shci)); > > Raw socket commands might actually work but here you are using it with > a user channel which afaik disables the stack processing. > > > > > Also, which API allows the user to control the advertising instance= s you describe? Are they automatically created by the kernel when HCI is s= ent to a raw socket to enable advertising? > > Nope you need to use the management interface to use the advertising > instances, or better yet use the D-Bus API: > > https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/advertising-a= pi.txt > > > > > Thanks, > > > > Martin > > > > > > > > _____________________________ > > > > Martin Turon | Google > > > > > > > > > > > > > > > > On Thu, Dec 13, 2018 at 1:49 PM Luiz Augusto von Dentz wrote: > > > >> > > > >> Hi Yunhan, > > > >> > > > >> The BlueZ API operates a bit different than HCI, it keeps re-enabl= ing the advertisement if there is any instance active, but the user can sto= p this by removing its instance once a connection is made, this is consider= ed more convenient than having the user to reprogram the advertisement on e= very disconnection. > > > >> > > > >> On Thu, 13 Dec 2018, 18:38 Yunhan Wang > > >>> > > > >>> +Martin > > > >>> > > > >>> Hi, Luiz and Marcel > > > >>> > > > >>> When I take a look at the bluetooth code, it seems it is re-enabl= ing > > > >>> ble advertisement after ble connection goes away. Any idea? > > > >>> > > > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetoo= th.git/tree/net/bluetooth/hci_event.c#n2634 > > > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetoo= th.git/tree/net/bluetooth/hci_event.c#n2712 > > > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetoo= th.git/tree/net/bluetooth/hci_request.c#n1386 > > > >>> https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetoo= th.git/tree/net/bluetooth/hci_request.c#n1734 > > > >>> > > > >>> Thanks > > > >>> Best wishes > > > >>> Yunhan > > > >>> On Wed, Dec 5, 2018 at 6:54 PM Yunhan Wang = 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 connec= tion 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 advert= ising > > > >>> > is bluez or kernel or application code? In other words, does ke= rnel or > > > >>> > bluez or application would re-enable the ble advertisement afte= r ble > > > >>> > disconnection happens? > > > >>> > > > > >>> > Thanks > > > >>> > Best wishes > > > >>> > Yunhan. > > > > -- > Luiz Augusto von Dentz