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,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 28A0DC65BAE for ; Fri, 14 Dec 2018 01:21:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7CD820879 for ; Fri, 14 Dec 2018 01:21:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rmDbTsMB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7CD820879 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.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 S1727775AbeLNBVk (ORCPT ); Thu, 13 Dec 2018 20:21:40 -0500 Received: from mail-ot1-f67.google.com ([209.85.210.67]:45204 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727638AbeLNBVk (ORCPT ); Thu, 13 Dec 2018 20:21:40 -0500 Received: by mail-ot1-f67.google.com with SMTP id 32so3861897ota.12 for ; Thu, 13 Dec 2018 17:21:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=fydq/tOKBTvj6972atheSIrka+aZdpikddvn/rPgw4A=; b=rmDbTsMBQGR0+nseEDpPen2alE49fjG6krcVtFeRhJQJSR7TAapElhbdg/N6ey6bGW Vr3pqDtfqTJohYBbCIRjgcM0I8AxYcimWmJczVZzSr4tCROJe+tcSU2Tbhm7L0h57pVZ RgagDmmz7eENERDq510Bo/eopEx9qE6JwGxW+9QJHzZHPtg5T5v7nvHmqf0I7bXJrrKf uEIo6ZN4H2ca/v5j8CWGN3z1b4+rCKpmYqILATXd5/zMDF9+LgJeQC8bqi5QE4w5GK3D GbH71k5UFI961l3Naie/iepjvr8fCkFa8jibaFbgftmuk92ADb0VgBMYPC8guPvBgbWS jQ2A== 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:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=fydq/tOKBTvj6972atheSIrka+aZdpikddvn/rPgw4A=; b=NVLOzXLAaPnSRd6ygcNAKw3CFL8HFEK6zv07jCuRPftvvhKo+T3GJkyflg+s8Pb0VP G53ks9FgkF5PWmeOrA8ZBjfuvgaHSZFN+d+dt3RmscQbddeDkQHEcMWrCxjyaiAoJvxA UOzl8pUvW2YrS1Ni9XVF9gYP93FQuxNQoxZoMW6iNZ5WZonmjE+WFShNGXedqXRAcGHD 4bn15u9Qak5BeWkIVFrGyASDEdaRNQF2mIB7Eq5oJbZjS6JNQH4Eln6BuBAXTT442135 kxMAqqjFVxg6vko452to1FrzJXruhoEYdtnBTV0IS6t/Gt725et+pj75FDML69AwNEn3 HZYg== X-Gm-Message-State: AA+aEWbG6HNDKgtTdm6/6V/v8ZL9GafBHHUrmdyRFCtEw3ga7lshN88n I/s+XKGPXkpmQ37soiw/cjZFj4elR2BEvMWWWVY= X-Google-Smtp-Source: AFSGD/X1v6pMpWGRubFXWDMhwvoTIEKi2YEuNeibbe1Lf6yoLAl+YY1KdO1zUsNOniicrXqu9TGKK33y943PmWYMcas= X-Received: by 2002:a9d:4c01:: with SMTP id l1mr784284otf.242.1544750498980; Thu, 13 Dec 2018 17:21:38 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Luiz Augusto von Dentz Date: Fri, 14 Dec 2018 03:21:24 +0200 Message-ID: Subject: Re: BLE advertisement re-enabling after ble connection goes away To: Yunhan Wang Cc: mturon@google.com, 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 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 wrote: > > > > 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 wrote: > > > > > > Hi Luiz, > > > > > > Is this behavior also expected on raw hci sockets? Because my observ= ation is that when working with raw hci over such sockets, auto-reenable do= es 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 instances = you describe? Are they automatically created by the kernel when HCI is sen= t 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-api= .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-enablin= g the advertisement if there is any instance active, but the user can stop = this by removing its instance once a connection is made, this is considered= more convenient than having the user to reprogram the advertisement on eve= ry 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-enablin= g > > >>> 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 w= rote: > > >>> > > > >>> > 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, "T= he > > >>> > device shall remain in general discoverable mode until a connecti= on 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 advertis= ing > > >>> > is bluez or kernel or application code? In other words, does kern= el or > > >>> > bluez or application would re-enable the ble advertisement after = ble > > >>> > disconnection happens? > > >>> > > > >>> > Thanks > > >>> > Best wishes > > >>> > Yunhan. --=20 Luiz Augusto von Dentz