Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751536AbdDAKNd (ORCPT ); Sat, 1 Apr 2017 06:13:33 -0400 Received: from mail7.pr.hu ([87.242.0.7]:33370 "EHLO mail7.pr.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751316AbdDAKNb (ORCPT ); Sat, 1 Apr 2017 06:13:31 -0400 From: Boszormenyi Zoltan Subject: Re: [Regression] Changes to i2c-piix4.c initialisation prevent loading of sp5100_tco watchdog driver on AMD SB800 chipset To: Guenter Roeck 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 Message-ID: Date: Sat, 1 Apr 2017 12:13:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170331150524.GA31555@roeck-us.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Score: 0.7 (/) X-Scan-Signature: 325f7eb36b407d36a457b6b1c0640019 X-Spam-Tracer: backend.mail.pr.hu 0.7 20170401101319Z Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1157 Lines: 28 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. 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