Return-path: Received: from mail-yb0-f194.google.com ([209.85.213.194]:33949 "EHLO mail-yb0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727392AbeH3ARe (ORCPT ); Wed, 29 Aug 2018 20:17:34 -0400 Received: by mail-yb0-f194.google.com with SMTP id t10-v6so2537221ybb.1 for ; Wed, 29 Aug 2018 13:19:04 -0700 (PDT) From: Jes Sorensen Subject: Re: rtl8723bu: low signal, fails to associate To: James Cameron , linux-wireless@vger.kernel.org, Mylene JOSSERAND , Stefan Pappalardo , Carlo Caione References: <20180824013645.GB761@us.netrek.org> Message-ID: (sfid-20180829_221924_214105_19383B91) Date: Wed, 29 Aug 2018 16:19:01 -0400 MIME-Version: 1.0 In-Reply-To: <20180824013645.GB761@us.netrek.org> Content-Type: text/plain; charset=utf-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 08/23/2018 09:36 PM, James Cameron wrote: > G'day Carlo, Mylene, and James, > > Thanks for your earlier reports about RTL8723bu. Have you any more > recent experiences you might share? > > I'm evaluating a sample laptop which worked fine with Windows 10, but > not very well with Ubuntu 18.04, and kernel v4.15 or kernel v4.18.4. > > The laptop is by Hena, model NT16-PRO-C-E, with a wireless device on > internal USB (0x0bda:0xb720) which loads rtl8xxxu, identifying as > RTL8723BU. > > http://dev.laptop.org/~quozl/z/1ft0qv.txt (dmesg) > > Symptoms are low RSSI on scan, very short range, and often a failure > to associate over a distance of two metres in a radio quiet location. > > Symptoms began after first power off, which suggests that device > registers programmed by the previous operating system Windows 10 had > not been reset by reboot into the Ubuntu 18.04 installer. The device > worked fine in Ubuntu 18.04 before the first power off. > > Jes, let me know if there is anything I can do to help. It's been a while since I had time to look at the 8723bu support, and rtl8xxxu doesn't have BT coexist support. I notice that your laptop does load the bluetooth module for 8723bu which I believe fiddles with the antenna configuration and is likely to take control of the antennas. I suspect this is why you see low signal quality on the WiFi side. If you blacklist the BT module, does it work better? Jes