From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933275AbeEHIhn (ORCPT ); Tue, 8 May 2018 04:37:43 -0400 Received: from rtits2.realtek.com ([211.75.126.72]:50748 "EHLO rtits2.realtek.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932644AbeEHIhh (ORCPT ); Tue, 8 May 2018 04:37:37 -0400 Authenticated-By: X-SpamFilter-By: BOX Solutions SpamTrap 5.62 with qID w488bHhp029504, This message is accepted by code: ctloc85258 From: Pkshih To: "jprvita@gmail.com" CC: "linux-kernel@vger.kernel.org" , "Larry.Finger@lwfinger.net" , "jprvita@endlessm.com" , Birming Chiu , "drake@endlessm.com" , Chaoming_Li , "kvalo@codeaurora.org" , =?utf-8?B?6I6K5b2l5a6j?= , "derosier@gmail.com" , Steven Ting , "netdev@vger.kernel.org" , "linux@endlessm.com" , Shaofu , "linux-wireless@vger.kernel.org" Subject: Re: RTL8723BE performance regression Thread-Topic: RTL8723BE performance regression Thread-Index: AQHTy7eSN578mCBr2kKVBzf45sjLwaPvW7kAgAACkICAAAPHAIAru2GAgADJ6dD//7BOgIAI5T6AgAC1FQA= Date: Tue, 8 May 2018 08:37:16 +0000 Message-ID: <1525768634.2885.11.camel@realtek.com> References: <059b40f0-b8e2-b55f-92d5-a859ba4204a4@lwfinger.net> <5B2DA6FDDF928F4E855344EE0A5C39D13BEC14C0@RTITMBSV07.realtek.com.tw> <1525240713.3735.3.camel@realtek.com> 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" Content-ID: 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 w488bpg5029286 On Mon, 2018-05-07 at 14:49 -0700, João Paulo Rechi Vita wrote: > On Tue, May 1, 2018 at 10:58 PM, Pkshih wrote: > > On Wed, 2018-05-02 at 05:44 +0000, Pkshih wrote: > >> > >> > -----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@endless > m.c > >> om > >> > 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. > >> > > > > Please pay attention to cold reboot once ant_sel is changed. > > >  > I've tested the commit mentioned above and it fixes the problem on top > of v4.16 (in addition to the latest wireless-drivers-next also been > fixed as it already contains such commit). On v4.15, we also need the > following commits before "af8a41cccf8f rtlwifi: cleanup 8723be ant_sel > definition" to have a good performance again: >  >   874e837d67d0 rtlwifi: fill FW version and subversion >   a44709bba70f rtlwifi: btcoex: Add power_on_setting routine >   40d9dd4f1c5d rtlwifi: btcoex: Remove global variables from btcoex v4.15 isn't longterm version and had been EOL. >  > Surprisingly, it seems forcing ant_sel=1 is not needed anymore on > these machines, as the shown by the numbers bellow (ant_sel=0 means > that actually no parameter was passed to the module). I have powered > off the machine and done a cold boot for every test. It seems > something have changed in the antenna auto-selection code since v4.11, > the latest point where I could confirm we definitely need to force > ant_sel=1. I've been trying to understand what causes this difference, > but haven't made progress on that so far, so any suggestions are > appreciated (we are trying to decide if we can confidently drop the > downstream DMI quirks for these specific machines). >  I think your rtl8723be module programed correct efuse content, so it works properly with ant_sel=0, and quirk isn't required for your machine. >   w-d-n ant_sel=0: -14.00 dBm,  69.5 Mbps -> good >   w-d-n ant_sel=1: -10.00 dBm,  41.1 Mbps -> good >   w-d-n ant_sel=2: -44.00 dBm,   607 kbps -> bad >  >   v4.16 ant_sel=0: -12.00 dBm,  63.0 Mbps -> good >   v4.16 ant_sel=1: - 8.00 dBm,  69.0 Mbps -> good >   v4.16 ant_sel=2: -50.00 dBm,   224 kbps -> bad >  >   v4.15 ant_sel=0: - 8.00 dBm,  33.0 Mbps -> good >   v4.15 ant_sel=1: -10.00 dBm,  38.1 Mbps -> good >   v4.15 ant_sel=2: -48.00 dBm,   206 kbps -> bad >  With your results, the efuse content is programmed as one or two antenna on AUX path. Regards, PK