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=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,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 9F5B1C282C4 for ; Tue, 12 Feb 2019 15:38:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6670B20811 for ; Tue, 12 Feb 2019 15:38:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=endlessm-com.20150623.gappssmtp.com header.i=@endlessm-com.20150623.gappssmtp.com header.b="zCg8eRoX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729347AbfBLPi5 (ORCPT ); Tue, 12 Feb 2019 10:38:57 -0500 Received: from mail-ed1-f67.google.com ([209.85.208.67]:37521 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726238AbfBLPi5 (ORCPT ); Tue, 12 Feb 2019 10:38:57 -0500 Received: by mail-ed1-f67.google.com with SMTP id m12so872829edv.4 for ; Tue, 12 Feb 2019 07:38:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=endlessm-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6pBqO3xp/1B0zFnqLcuHxvRhsA22yWdbUAXgQ9hiknQ=; b=zCg8eRoXWYBCsvybjdNlWj+M2/h3YmOBzi/7XcMpsOgtWZyBTfDzfFxs9XwhtBVn7T mRvFAAvf9bfpdznKU1/l08JzkwQQZ+iEoTylOSpMVyaPr88u7XU9a9275aT7QlImrFzp 8QzaIFTC0iPrvIABUzL7JbEbHMwA3n0/kAJSck02gsez/RipoQhcIshWMF0dKWfdMKAV TlX1t/RENSvqxsedrT/t6PuKQ/5+wP2XRIcBsBp6j+4sLPVA+bgVCCsJgo45rSncaj5V +jcgMX/b8DMGoovR1lEin4/lluBTqn1a/CAFtZXyuaJWQJXteeSdYaJ0EYp6ismOqQn/ MPEA== 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; bh=6pBqO3xp/1B0zFnqLcuHxvRhsA22yWdbUAXgQ9hiknQ=; b=haPmMZorBqhkqxvTigp9mvu7mJRd9uoytP4mdm6URL7JtQ7IvPxZKnQBRkzrs8wnnY GUicyLXiCEmyiT0eiFyId3k6r+KvnsJvq5Vt+yJoHp+nzQJRYuMTCCqjomPaS68lCzlJ vym9ni+8wGN69vnvre1hJUzNIc+ATx2X0Z/ojWG72HzjDwy2k7QUnaC70eefOU8F3FkR 2s/KzwqNAYpMIZv+b4Km8vLN4UqfCACl2j3VYUhg7+ZUW6HjipNaehqQjEoU4Imy9tf0 sXsjOhfOI4rT+fZ+3eEQxCXP2KAyiQoq9UKYLygSuxgzJSYhIf/4bNbSooaqlJIIG2DM gRGA== X-Gm-Message-State: AHQUAuZTpghOfhyvERcEVx+DzNk/GQzDAUc6OPTJ9mEjj4gbuun/C6no 2HM4OufKzGA9MjUZ7d4IW+iGDmwwzA/7d3MVuIBlAg== X-Google-Smtp-Source: AHgI3IaqXo4ydZf//Hn6G1eGoZsai+hu999Ws03JREaJu8Yt5Nhi1slh3Sw6Ef7qpTW+BCsvxCOOEEhxp79iAiXfAeQ= X-Received: by 2002:a17:906:9a2:: with SMTP id q2mr3177416eje.40.1549985935042; Tue, 12 Feb 2019 07:38:55 -0800 (PST) MIME-Version: 1.0 References: <20180111103006.GA17574@thinktank.home.org> <14c5f7f4-0d5b-cecd-b45b-3672b67da07a@gmail.com> In-Reply-To: From: Chris Chiu Date: Tue, 12 Feb 2019 23:38:44 +0800 Message-ID: Subject: Re: RTL8723bu: poor signal and connection troubles To: Carlo Caione Cc: Jes Sorensen , Barry Day , kvalo@codeaurora.org, linux-wireless@vger.kernel.org, mylene.josserand@free-electrons.com, Linux Upstreaming Team Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Tue, Jan 29, 2019 at 5:56 PM Chris Chiu wrote: > > On Mon, Jan 22, 2018 at 6:56 AM Carlo Caione wrote: > > > > On Sun, Jan 21, 2018 at 9:46 PM, Jes Sorensen wrote: > > > On 01/11/2018 05:30 AM, Barry Day wrote: > > > > > One issue with rtl8723bu is that it needs to coexist with the bluetooth > > > driver. When I wrote the rtl8723bu support that was no BT support for > > > the chip in the kernel and it worked fine, at least for me. However if > > > you load the BT driver for the dongle which someone pushed into the > > > kernel since then, it is likely to hijack the antennas causing the weak > > > signal you describe. > > > > Yeah, that's why when testing the dongle I carefully disabled BT and > > made sure no BT driver was probed at all. Still I can see the issue. > > I honestly doubt that the problem is caused by BT coexistence. Any > > other idea or suggestion to debug this problem? > > > > Thanks, > > > > -- > > Carlo Caione | +44.7384.69.16.04 | Endless > > This problem has been reported for 1 year, but it still persists now. > > I found that the problem disappeared after I resume from suspend. Before > suspend, the rssi observed from AP side for this dongle is quite poor. But > it comes back to normal after resume. The signal strength differs almost > 30dBm. So I compared/checked the RF/BB related register values > (in .init_phy_bb/.init_phy_rf/.set_tx_power) but they are identical with the > same routines in the driver from https://github.com/lwfinger/rtl8723bu > > The registers also remain the same across suspend/resume. Don't really > know why a simple suspend/resume could cause such difference. Can > anyone suggest which part I should look into to get more information? > > Chris I found one thing interesting. It does seem to be related to BT coexist just as Jes mentioned. Follow the steps below and the signal can always come back to normal. The '1-7:1.0' is one of the IDs for the rtl8723bu usb interface. 1. unbind btusb first, cd /sys/bus/usb/drivers/btusb; echo 1-7:1.0 > unbind 2. unload rtl8xxxu driver then reload it. The signal stays at poor level 3. bind the btusb. cd /sys/bus/usb/drivers/btusb; echo 1-7:1.0 > bind Seems that the BT firmware loaded is helpful for the only antenna config which is shared by WiFi/BT. If I load the BT firmware after rtl8xxxu driver, everything's fine. Can anyone suggest the next step? I've compared all registers and h2c cmds between vendor driver and rtl8xxxu driver. Basically, they're almost the same even the bt coexist related settings. So it's difficult to imagine why the same power on sequence setting and RF enable setting cause that huge signal difference. Chris