Return-path: Received: from mail-oi0-f65.google.com ([209.85.218.65]:37184 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726117AbeHWUgn (ORCPT ); Thu, 23 Aug 2018 16:36:43 -0400 MIME-Version: 1.0 In-Reply-To: <87in41nxfx.fsf@kamboji.qca.qualcomm.com> References: <20180208052801.15670-1-kai.heng.feng@canonical.com> <56d650e6-d26f-087c-4e86-2e5d4e859414@nbd.name> <87k1vmeip8.fsf@kamboji.qca.qualcomm.com> <7170e2d5-a59d-8260-fa8e-f02f583b773f@nbd.name> <6A0F65EF-A7C4-469F-8FAF-CBE314676237@canonical.com> <9AF82E83-2EBE-4076-BAFA-EEA44B1DB423@canonical.com> <87in41nxfx.fsf@kamboji.qca.qualcomm.com> From: Tom Psyborg Date: Thu, 23 Aug 2018 19:06:04 +0200 Message-ID: (sfid-20180823_190615_315944_226A37F9) Subject: Re: [PATCH] ath9k: turn on btcoex_enable as default To: Kalle Valo Cc: Kai-Heng Feng , Felix Fietkau , ath9k-devel@qca.qualcomm.com, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: I keep this setting on all the time and just when i read this mail again i'm suspicious if the bluetooth could actually have an impact on wifi reception? I am using AR9462 card and it can transmit at 215Mbps average, but receives only about 125Mbps (2spatial streams AP, 2.4GHz, AR9531) On 23/08/2018, Kalle Valo wrote: > Kai-Heng Feng writes: > >> at 12:15, Kai Heng Feng wrote: >> >>> >>> >>>> On 10 Feb 2018, at 10:05 PM, Felix Fietkau wrote: >>>> >>>> On 2018-02-10 14:56, Kai Heng Feng wrote: >>>>>> On 9 Feb 2018, at 3:16 PM, Kalle Valo wrote: >>>>>> Sure, but we have to make sure that we don't create regressions on >>>>>> existing systems. For example, did you test this with any system >>>>>> which >>>>>> don't support btcoex? (just asking, haven't tested this myself) >>>>> >>>>> No not really, but I will definitely test it. >>>>> The only module I have that uses ath9k is Dell=E2=80=99s DW1707. >>>>> How do I check if it support btcoex or not? >>>> I just reviewed the code again, and I am sure that we cannot merge thi= s >>>> patch. Enabling the btcoex parameter makes the driver enable a whole >>>> bunch of code starting timers, listening to some GPIOs, etc. >>>> >>>> On non-btcoex systems, some of those GPIOs might be floating or even >>>> connected to different things, which could cause a lot of undefined >>>> behavior. >>>> >>>> This is simply too big a risk, so there absolutely needs to be a >>>> whitelist for systems that need this, otherwise it has to remain >>>> disabled by default. >>> >>> So what information can we use to whitelist btcoex chips? >>> Can we get btcoex support status at ath9k probing? >> >> Sorry for bringing this up again. >> >> Is DMI based match an acceptable approach for ath9k? > > I don't know what Felix thinkgs, but to me using DMI sounds like a good > idea to try, assuming the matches are unique enough and there's no risk > of enabling bt coex on wrong platforms. Should the PCI bus number etc > checked as well in case the user adds more ath9k devices to the > platform? > > But of course I need to see the patch to comment more. > > -- > Kalle Valo >