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,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 E0A00C65BAE for ; Thu, 13 Dec 2018 23:10:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70BD72054F for ; Thu, 13 Dec 2018 23:10:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nestlabs.com header.i=@nestlabs.com header.b="d/OEKH5u" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70BD72054F 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 S1726281AbeLMXKj (ORCPT ); Thu, 13 Dec 2018 18:10:39 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:55327 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbeLMXKi (ORCPT ); Thu, 13 Dec 2018 18:10:38 -0500 Received: by mail-it1-f196.google.com with SMTP id o19so6287702itg.5 for ; Thu, 13 Dec 2018 15:10:38 -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=SOpMkYPdQbr2MzH/Re3fPRrwAt9o7A06k3W2O+tY6MU=; b=d/OEKH5u3fiUbnmjmyWM7s76JbWtGd7c9on8BknT6duZf9Jc5seAYrl3yktppLUVWE tKsMt9yD80tx8j/OnT+K626UZj1Ti+eWTK6A6QSVDRkUaeWdn+NQSBIBCqoUUNnECXga pel2MHCyAspp0PT4eZGQxlSfhGrHjWCFRScr4= 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=SOpMkYPdQbr2MzH/Re3fPRrwAt9o7A06k3W2O+tY6MU=; b=Xh6w9GB40Jaoz7RXEBST5U+mQTG+pCWL07xCVUFhN76w8i66xWp7LxLEWMj9LkqRpI JyxjDv5LZbXwBlxk9vpxym2IKe0Ve9kGuP3RRWA4SUSJRebvs0g6lyuEywsFFQfGN6Z0 ZLiBSZreFvVJaW243C/xSCBN7gGnhjCSVmCxD+NMqlomHPbxrH2ic9PfJUv0YTYTOaf7 /gauwrCc2na+85hw5EXf6PYQlwDPleNFNiRc5xNs+lDfEtsbGvDlUKTFwBN0lsSAGj0q NlpS7CRUYZF5MQgmNuEF0Y0t1UCgXvZfCKhxSMkmIFgYnIW1on8xLbTto6GSVc5wTO0+ YfWQ== X-Gm-Message-State: AA+aEWaiNpjgphrbRO1J2J2QDQjLhBYYZBi4CLJKnEblFGhXFQmYsl5H yZ0lvX4Z5RyknkfRp5YMVRRzRg5Ho0s5wwi9u9BVxA== X-Google-Smtp-Source: AFSGD/WAKYhB/CiTCmzsRDpd45/28hC5ug9svEFy/8deN+R/YkKyUQkVFvCeXXUKUFj67az0PgWd9qmzaJbqilLK5HM= X-Received: by 2002:a02:c88:: with SMTP id 8mr679752jan.87.1544742637480; Thu, 13 Dec 2018 15:10:37 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Reply-To: yunhanw@nestlabs.com From: Yunhan Wang Date: Thu, 13 Dec 2018 15:10:25 -0800 Message-ID: Subject: Re: BLE advertisement re-enabling after ble connection goes away To: Martin Turon , Luiz Augusto von Dentz , Marcel Holtmann Cc: 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 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 observatio= n is that when working with raw hci over such sockets, auto-reenable does n= ot 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)); > > Also, which API allows the user to control the advertising instances you = describe? Are they automatically created by the kernel when HCI is sent to= a raw socket to enable advertising? > > 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-enabling th= e 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 mor= e convenient than having the user to reprogram the advertisement on every d= isconnection. >> >> 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-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 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 i= s >>> > 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 o= r >>> > bluez or application would re-enable the ble advertisement after ble >>> > disconnection happens? >>> > >>> > Thanks >>> > Best wishes >>> > Yunhan.