From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751216AbeEBFpC (ORCPT ); Wed, 2 May 2018 01:45:02 -0400 Received: from rtits2.realtek.com ([211.75.126.72]:55000 "EHLO rtits2.realtek.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751111AbeEBFo7 (ORCPT ); Wed, 2 May 2018 01:44:59 -0400 Authenticated-By: X-SpamFilter-By: BOX Solutions SpamTrap 5.62 with qID w425idLh009662, This message is accepted by code: ctloc85258 From: Pkshih To: =?utf-8?B?Sm/Do28gUGF1bG8gUmVjaGkgVml0YQ==?= , "Larry Finger" CC: Steve deRosier , =?utf-8?B?6I6K5b2l5a6j?= , Birming Chiu , Shaofu , Steven Ting , Chaoming_Li , Kalle Valo , linux-wireless , Network Development , LKML , Daniel Drake , =?utf-8?B?Sm/Do28gUGF1bG8gUmVjaGkgVml0YQ==?= , "linux@endlessm.com" Subject: RE: RTL8723BE performance regression Thread-Topic: RTL8723BE performance regression Thread-Index: AQHTy7eSN578mCBr2kKVBzf45sjLwaPvW7kAgAACkICAAAPHAIAru2GAgADJ6dA= Date: Wed, 2 May 2018 05:44:38 +0000 Message-ID: <5B2DA6FDDF928F4E855344EE0A5C39D13BEC14C0@RTITMBSV07.realtek.com.tw> References: <059b40f0-b8e2-b55f-92d5-a859ba4204a4@lwfinger.net> In-Reply-To: Accept-Language: en-US, zh-TW Content-Language: zh-TW X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.21.69.146] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w425jDEM029030 > -----Original Message----- > From: João Paulo Rechi Vita [mailto:jprvita@gmail.com] > Sent: Wednesday, May 02, 2018 6:41 AM > To: Larry Finger > Cc: Steve deRosier; 莊彥宣; Pkshih; Birming Chiu; Shaofu; Steven Ting; Chaoming_Li; Kalle Valo; > linux-wireless; Network Development; LKML; Daniel Drake; João Paulo Rechi Vita; linux@endlessm.com > Subject: Re: RTL8723BE performance regression > > On Tue, Apr 3, 2018 at 7:51 PM, Larry Finger wrote: > > On 04/03/2018 09:37 PM, João Paulo Rechi Vita wrote: > >> > >> On Tue, Apr 3, 2018 at 7:28 PM, Larry Finger > >> wrote: > >> > >> (...) > >> > >>> As the antenna selection code changes affected your first bisection, do > >>> you > >>> have one of those HP laptops with only one antenna and the incorrect > >>> coding > >>> in the FUSE? > >> > >> > >> Yes, that is why I've been passing ant_sel=1 during my tests -- this > >> was needed to achieve a good performance in the past, before this > >> regression. I've also opened the laptop chassis and confirmed the > >> antenna cable is plugged to the connector labeled with "1" on the > >> card. > >> > >>> If so, please make sure that you still have the same signal > >>> strength for good and bad cases. I have tried to keep the driver and the > >>> btcoex code in sync, but there may be some combinations of antenna > >>> configuration and FUSE contents that cause the code to fail. > >>> > >> > >> What is the recommended way to monitor the signal strength? > > > > > > The btcoex code is developed for multiple platforms by a different group > > than the Linux driver. I think they made a change that caused ant_sel to > > switch from 1 to 2. At least numerous comments at > > github.com/lwfinger/rtlwifi_new claimed they needed to make that change. > > > > Mhy recommended method is to verify the wifi device name with "iw dev". Then > > using that device > > > > sudo iw dev scan | egrep "SSID|signal" > > > > I have confirmed that the performance regression is indeed tied to > signal strength: on the good cases signal was between -16 and -8 dBm, > whereas in bad cases signal was always between -50 to - 40 dBm. I've > also switched to testing bandwidth in controlled LAN environment using > iperf3, as suggested by Steve deRosier, with the DUT being the only > machine connected to the 2.4 GHz radio and the machine running the > iperf3 server connected via ethernet. > We have new experimental results in commit af8a41cccf8f46 ("rtlwifi: cleanup 8723be ant_sel definition"). You can use the above commit and do the same experiments (with ant_sel=0, 1 and 2) in your side, and then share your results. Since performance is tied to signal strength, you can only share signal strength. Regards PK