Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D026C4332F for ; Thu, 25 Nov 2021 12:28:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353035AbhKYMbr (ORCPT ); Thu, 25 Nov 2021 07:31:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347043AbhKYMaE (ORCPT ); Thu, 25 Nov 2021 07:30:04 -0500 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [IPv6:2a01:488:42:1000:50ed:8234::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C725FC061759; Thu, 25 Nov 2021 04:26:52 -0800 (PST) Received: from ip4d173d4a.dynamic.kabel-deutschland.de ([77.23.61.74] helo=[192.168.66.200]); authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1mqDpr-0006L6-UD; Thu, 25 Nov 2021 13:26:44 +0100 Message-ID: <332a19f1-30f0-7058-ac18-c21cf78759bb@leemhuis.info> Date: Thu, 25 Nov 2021 13:26:43 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: [PATCHv2] Bluetooth: quirk disabling LE Read Transmit Power Content-Language: en-BS To: Aditya Garg , Marcel Holtmann Cc: Orlando Chamberlain , Daniel Winkler , Greg KH , Johan Hedberg , "linux-bluetooth@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Luiz Augusto von Dentz , "regressions@lists.linux.dev" , "sonnysasaka@chromium.org" References: <20211001083412.3078-1-redecorating@protonmail.com> <70a875d0-7162-d149-dbc1-c2f5e1a8e701@leemhuis.info> <20211116090128.17546-1-redecorating@protonmail.com> <3B8E16FA-97BF-40E5-9149-BBC3E2A245FE@live.com> <52DEDC31-EEB2-4F39-905F-D5E3F2BBD6C0@live.com> <8919a36b-e485-500a-2722-529ffa0d2598@leemhuis.info> <20211117124717.12352-1-redecorating@protonmail.com> <40550C00-4EE5-480F-AFD4-A2ACA01F9DBB@live.com> From: Thorsten Leemhuis In-Reply-To: <40550C00-4EE5-480F-AFD4-A2ACA01F9DBB@live.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1637843212;64181b7a; X-HE-SMSGID: 1mqDpr-0006L6-UD Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, this is your Linux kernel regression tracker speaking again. On 19.11.21 17:59, Aditya Garg wrote: >> On 18-Nov-2021, at 12:31 AM, Marcel Holtmann wrote: >>>> So if this just affects two macs, why can't the fix be realized as a >>>> quirk that is only enabled on those two systems? Or are they impossible >>>> to detect clearly via DMI data or something like that? >>> >>> I think we should be able to quirk based off the acpi _CID "apple-uart-blth" >>> or _HID "BCM2E7C". Marcel suggested quirking based of the acpi table here >>> https://lore.kernel.org/linux-bluetooth/1D2217A9-EA73-4D93-8D0B-5BC2718D4788@holtmann.org/ >>> >>> This would catch some unaffected Macs, but they don't support the LE Read >>> Transmit Power command anyway (the affected macs were released after it >>> was added to the Bluetooth spec, while the unaffected Macs were released >>> before it was added to the spec, and thus don't support it). >>> >>> I'm not sure how to go about applying a quirk based off this, there are >>> quirks in drivers/bluetooth/hci_bcm.c (no_early_set_baudrate and >>> drive_rts_on_open), but they don't seem to be based off acpi ids. >>> >>> It might be simpler to make it ignore the Unknown Command error, like >>> in this patch https://lore.kernel.org/linux-bluetooth/CABBYNZLjSfcG_KqTEbL6NOSvHhA5-b1t_S=3FQP4=GwW21kuzg@mail.gmail.com/ >>> however that only applies on bluetooth-next and needed the status it >>> checks for to be -56, not 0x01. >> >> so we abstain from try-and-error sending of commands. The Bluetooth spec >> has a list of supported commands that a host can query for a reason. This >> is really broken behavior of the controller and needs to be pointed out as >> such. > Well all I can do is provide you any logs or information I can. But we do really wish to get this regression fixed soon. >> >> The question is just how we quirk it. This thread once again looks stalled and smells a lot like "everyone agrees that his should be fixed, but afaics nobody submitted a fix or committed to work on one". Please speak up if my impression is wrong, as this is a regression and thus needs to be fixed, ideally quickly. Part of my job is to make that happen and thus remind developers and maintainers about this until we have a fix. Ciao, Thorsten #regzbot title bluetooth: "Query LE tx power on startup" broke Bluetooth on MacBookPro16,1 #regzbot poke