From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756388AbdKCSwe (ORCPT ); Fri, 3 Nov 2017 14:52:34 -0400 Received: from mail-lf0-f41.google.com ([209.85.215.41]:57207 "EHLO mail-lf0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751290AbdKCSwa (ORCPT ); Fri, 3 Nov 2017 14:52:30 -0400 X-Google-Smtp-Source: ABhQp+QtqLFVGj0DwnyE+X/Wm2myNuYN2ApsOwXOf9ptp2C6KWjGdXpxT3XYrULFiQdfwVchpsc80Q== Subject: Re: T20 Cpuidle Freeze To: Marcel Ziswiler , "linux-kernel@vger.kernel.org" , "linux-tegra@vger.kernel.org" , "rafael.j.wysocki@intel.com" Cc: "thierry.reding@gmail.com" , "mirq-linux@rere.qmqm.pl" References: <1509714423.21320.11.camel@toradex.com> From: Dmitry Osipenko Message-ID: Date: Fri, 3 Nov 2017 21:52:26 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <1509714423.21320.11.camel@toradex.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03.11.2017 16:07, Marcel Ziswiler wrote: > Hi Rafael, dear community > > One of our customers reported seeing freezes when running the LTS Linux > kernel 4.9.x on our Toradex Colibri T20 modules [1]. I was able to > reproduce a complete SoC lock-up after a few minutes also running the > latest 4.14-rc7 while LTS 4.4.x seemed to run stable. > > Having attempted a multi-level bisection points towards the following > first bad commit: > > 9c4b2867ed7c8c8784dd417ffd16e705e81eb145 > > cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0 > > Unfortunately as drivers/cpuidle/governors/menu.c has gotten further > edits since it seems not trivial to just revert it. > > However I found out that it indeed has to do with CPU idle as when I > did disable the CONFIG_CPU_IDLE Linux kernel configuration option also > LTS 4.9.59 as well as latest 4.14-rc7 run now stable overnight. > > Does anybody have any clue what exactly may be happening and/or why > cpuidle may not run stable on T20? Or is everybody always just > disabling cpuidle on T20 anyway? > > Thanks! > > [1] https://www.toradex.com/community/questions/16838/actual-lts-kernel > -49-on-colibri-t20.html I haven't seen any problems with the cpuidle on next and 4.14-rc7 works fine. # cat /sys/devices/system/cpu/cpu[0-1]/cpuidle/state[0-1]/usage 162283 32905 254669 32905 # cat /sys/devices/system/cpu/cpu[0-1]/cpuidle/state[0-1]/time 436981763 2110484666 458260707 2121781516 # uptime 18:50:24 up 44 min, 1 user, load average: 0.15, 0.08, 0.07 It could be that cpuidle unmasks some other issue on the Colibri.