From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753228AbdLURU4 (ORCPT ); Thu, 21 Dec 2017 12:20:56 -0500 Received: from mail-io0-f193.google.com ([209.85.223.193]:38693 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752156AbdLURUy (ORCPT ); Thu, 21 Dec 2017 12:20:54 -0500 X-Google-Smtp-Source: ACJfBovEvhp4teMnDYrL36T6cLBZqfcJ4w1t/zFc7s5S8Lq0V94flxiVHjHEpbJRvHynnmLScHOkEw== MIME-Version: 1.0 In-Reply-To: <20171221083052.GA19501@kroah.com> References: <20171218152852.624624481@linuxfoundation.org> <20171220195112.GA1287@google.com> <20171221083052.GA19501@kroah.com> From: Brian Norris Date: Thu, 21 Dec 2017 09:20:51 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 4.4 009/115] Bluetooth: btusb: driver to enable the usb-wakeup feature To: "gregkh@linuxfoundation.org" Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sukumar Ghorai , Amit K Bag , Oliver Neukum , Marcel Holtmann , Matthias Kaehlcke , Todd Broch , Rajat Jain , Miao Chou , sadashiva.rao.pv@intel.com, Guenter Roeck Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 21, 2017 at 12:30 AM, gregkh@linuxfoundation.org wrote: > As Linus's tree is also broken, being bug-compatible here is good, > right? I can just apply the revert/fix patch when it lands in that > tree, and all will be ok. > > Or is Linus's tree not broken now? Sorry, this whole thread has been > really confusing... Linus' tree is broken in 2 ways: 1. It includes this patch: "Bluetooth: btusb: fix QCA Rome suspend/resume" which is wrong, and we're on our way to reverting it upstream and backporting that to -stable. 2. It includes $subject patch. I'm not quite so sure, but I believe it's not 100% "wrong"; it's just tougher for user space to deal with, since now by default, all sorts of BT devices are set to be wakeup sources. We can account for that in user space by being more careful with initiating BT activity before suspend, but we don't currently do that (at least not with the BlueZ in ChromeOS). A related portion of this problem is that we briefly thought that this patch resolved regressions with 1. In the end, it might mask some, but it does not actually fix the problem. But then, you only included this patch because somebody suggested it could resolve 1... In the end, I'd say that #2 never belonged in -stable at all, and #1 was just "buggy" (so we're reverting it and letting the revert trickle into -stable). I'm not sure I have a strong reason to revert #2 upstream, but I think I have an argument for not including it in -stable. I'm not sure what you mean by "bug-compatible"; if I wanted to use a buggy kernel, I'd use Linus' tree :) Or as I think I understand your point: the key point is that #2 might not be actually a "bug", but a feature that user space has to be more careful with. That may be a candidate for mainline, but not for -stable, as I understand the current rules. Brian