Return-path: Received: from mail-qk0-f173.google.com ([209.85.220.173]:38863 "EHLO mail-qk0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750742AbeCIJfl (ORCPT ); Fri, 9 Mar 2018 04:35:41 -0500 Received: by mail-qk0-f173.google.com with SMTP id s198so2949231qke.5 for ; Fri, 09 Mar 2018 01:35:41 -0800 (PST) Subject: Re: brcmfmac signal/interference issues To: Steve deRosier References: <5A8D36B7.1010201@broadcom.com> <5A8FE4D9.80608@broadcom.com> <5AA114A9.8050801@broadcom.com> Cc: Daniel Drake , franky.lin@broadcom.com, hante.meuleman@broadcom.com, chi-hsien.lin@cypress.com, Wright Feng , linux-wireless , brcm80211-dev-list.pdl@broadcom.com, brcm80211-dev-list@cypress.com, Linux Upstreaming Team From: Arend van Spriel Message-ID: <5AA25567.60102@broadcom.com> (sfid-20180309_103546_390528_D35C5ECF) Date: Fri, 9 Mar 2018 10:35:35 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 3/8/2018 4:54 PM, Steve deRosier wrote: > On Thu, Mar 8, 2018 at 2:47 AM, Arend van Spriel > wrote: >> On 2/23/2018 2:49 PM, Daniel Drake wrote: >>> >>> On Fri, Feb 23, 2018 at 12:54 PM, Arend van Spriel >>> wrote: >>>> >>>> Yup. Windows firmware talks NDIS. If you run 'strings 4345r6rtecdc.bin | >>>> tail -1' you can see the firmware build target and it likely has 'ndis' >>>> in >>>> it. >> >> >> Hi Daniel, >> >> Bit late response. Sorry. >> >>> >>> 43455c0-roml/sdio-ag-ndis-vista-pktfilter-d0c-pno-aoe-p2p-dhdoid-ndoe-gtkoe-mfp-proptxstatus-dmatxrc-keepalive-ap-ampduretry-pclose-txbf >>> >>> Yes, ndis. So no easy way to run the same firmware on the 2 OSes. >> >> >> Indeed. I could try building nearly same firmware target. Can you provide >> the firmware version as well. >> >> Now reading over your orignal email again: >> >>> If I place both antenna terminals inside the Linux MiniPC case, the >>> Linux pings are bad but the Windows pings are fine. >>> >>> If I place both antenna terminals inside the Windows MiniPC case, it >>> is the same: Linux pings are bad, but the Windows pings are fine. >>> >>> And when the Linux antenna is placed outside of both cases, the Linux >>> pings are fine. I've repeated these tests a handful of times in quick >>> succession to make sure that I'm not going crazy and that this is not >>> a case of the problem intermittency causing misleading results. These >>> findings appear very solid. >> >> So it picks up something in the PC. Some sources of interference that I have >> seen before are USB3 and HDMI. Maybe try to shield those if present and see >> if that helps. The nvram contains sensitivity parameters, but as you stated >> you are using the same nvram for windows and linux for now we can rule it >> out for debugging the issue. >> > > Hi Daniel, > > I'll jump in here too... > > Did you check the Bluetooth? I don't know if this chip has it or if > it's an independent chip on this board, but if Linux is leaving it > powered up but not properly configured you could have issues. And in > some designs, the BT and WiFi will share a single antenna. Note that > I'm not saying you've configured BT to run, I'm actually suggesting > that the pin that enables it is on, but you might not be loading the > BT drivers and firmware and so the thing is just in a wonky > uninitialized state. Or you do have it enabled and should try turning > it off. Either way. > > And WiFi/BT coex has always been a bit of a problem (speaking > generally, I don't know the status with this particular chip) in > Linux. I see WiFi and BT interfering with each other frequently in my > testing setups with my dev boards. Often I can magically make problems > go away by simply pulling the enable line high (which is "off"). Thanks, Steve Disabling BT was indeed suggested, but indeed pulling BT_REG_ON high will ensure there is nothing active on BT side. In BT the firmware is generally speaking on-chip with possibility to download firmware patch to the device. However, if no driver does hci initialization I would expect BT to be passive/silent, but I guess your magic proves otherwise ;-) Regards, Arend