Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753113AbdLULoA (ORCPT ); Thu, 21 Dec 2017 06:44:00 -0500 Received: from mail-ot0-f195.google.com ([74.125.82.195]:37262 "EHLO mail-ot0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752402AbdLULnz (ORCPT ); Thu, 21 Dec 2017 06:43:55 -0500 X-Google-Smtp-Source: ACJfBouHrCsQYJxe4mNVExZ2/OPkWjOd5DMJSiYORpkrALPO4Ik49PSsdYnKmfzx8+PIU7DOG+ZW9uWs2U+YlV4YfaU= MIME-Version: 1.0 In-Reply-To: <20171220185308.GA176644@google.com> References: <20171220110008.11856-1-kai.heng.feng@canonical.com> <20171220185308.GA176644@google.com> From: Daniel Drake Date: Thu, 21 Dec 2017 11:43:54 +0000 Message-ID: Subject: Re: [PATCH 1/2] Revert "Bluetooth: btusb: fix QCA Rome suspend/resume" To: Brian Norris Cc: Kai-Heng Feng , Greg Kroah-Hartman , Marcel Holtmann , Linux USB Mailing List , Linux Bluetooth mailing list , Linux Kernel , stable@vger.kernel.org, Leif Liddy , Matthias Kaehlcke , 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 Content-Length: 848 Lines: 17 On Wed, Dec 20, 2017 at 6:53 PM, Brian Norris wrote: > > On Wed, Dec 20, 2017 at 07:00:07PM +0800, Kai-Heng Feng wrote: > > This commit causes a regression on some QCA ROME chips. The USB device > > reset happens in btusb_open(), hence firmware loading gets interrupted. > > Oh, did you really confirm that's the root of the problem? I was only > hypothesizing, with some informed observation and code review; but I > didn't fully convince myself. If so, that's interesting. I have the same doubt. Can you explain how/why firmware uploading and btusb_open() overlap, and how this is avoided with your patch? If they do overlap, is that not a bug in the stack that should be fixed instead? If the fix belongs in btusb and this BTUSB_RESET_RESUME thing really is problematic, should it be totally removed instead? Daniel