Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751798AbdDANcp (ORCPT ); Sat, 1 Apr 2017 09:32:45 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:53411 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751574AbdDANcn (ORCPT ); Sat, 1 Apr 2017 09:32:43 -0400 Subject: Re: [Regression] Changes to i2c-piix4.c initialisation prevent loading of sp5100_tco watchdog driver on AMD SB800 chipset To: Boszormenyi Zoltan References: <1485728348.3220.10.camel@googlemail.com> <1488530782.2457.41.camel@users.sourceforge.net> <20170303101702.GA1669@katana> <1490944639.2653.182.camel@users.sourceforge.net> <585a27fb-be15-df9f-00a9-bd4c3a654142@roeck-us.net> <20170331150524.GA31555@roeck-us.net> Cc: Paul Menzel , Wolfram Sang , Christian Fetzer , Jean Delvare , linux-i2c@vger.kernel.org, linux-watchdog@vger.kernel.org, 853122@bugs.debian.org, Wim Van Sebroeck , Tim Small , Nehal Shah , Mika Westerberg , Andy Shevchenko , Thomas Brandon , Eddi De Pieri , linux-kernel@vger.kernel.org From: Guenter Roeck Message-ID: <0b32728a-f545-be43-2870-94688f1f9da5@roeck-us.net> Date: Sat, 1 Apr 2017 06:32:37 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1551 Lines: 40 On 04/01/2017 03:13 AM, Boszormenyi Zoltan wrote: > 2017-03-31 17:05 keltezéssel, Guenter Roeck írta: >> On Fri, Mar 31, 2017 at 04:46:02PM +0200, Boszormenyi Zoltan wrote: >>> 2017-03-31 14:49 keltezéssel, Guenter Roeck írta: >>>> request_muxed_region() can fail, and literally every other driver >>>> using it checks for that failure. Please do the same. >>> >>> In what circumstances can request_muxed_region() fail? As far as >>> I can see, only if two drivers use the same I/O port base and the >>> already present region did not use IORESOURCE_MUXED which is >>> not the case here. When request_muxed_region() is used consistently, >>> subsequent requests are put on a wait queue and the first one is >>> woken up when the region is released. So, it's basically a mutex. >>> Am I missing something here? >>> >> >> Yes. failure to allocate the resource is one. > > So, a common mutex should be used. > Just because you don't want to check for errors ? I am not on favor of your new solution. I think it violates layering all over the place, and I dislike the idea of having a global mutex as you propose. I won't shut it down, but I'll let others provide feedback on your new series of patches. Guenter > I have also added synchronization to the USB PCI quirks code and > have split the patch into three pieces now (USB quirks, i2c-piix4 and > sp5100_tco) and they were sent to the relevant mailing lists. > > I don't know which subsystem wants to take it, all 3 patches are > needed at once. > > Best regards, > Zoltán Böszörményi >