Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754218AbaDAXp7 (ORCPT ); Tue, 1 Apr 2014 19:45:59 -0400 Received: from mail.windriver.com ([147.11.1.11]:62729 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751508AbaDAXp5 (ORCPT ); Tue, 1 Apr 2014 19:45:57 -0400 Date: Tue, 1 Apr 2014 19:46:13 -0400 From: Paul Gortmaker To: "Brown, Len" CC: "WYSOCKI, RAFAL" , Arne Bockholdt , Jiang Liu , "x86@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: Regression in intel_idle on Avaton/Rangely Mohon Peak board Message-ID: <20140401234612.GA22782@windriver.com> References: <533B0288.2020304@windriver.com> <1A7043D5F58CCB44A599DFD55ED4C948452FD582@FMSMSX106.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1A7043D5F58CCB44A599DFD55ED4C948452FD582@FMSMSX106.amr.corp.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [RE: Regression in intel_idle on Avaton/Rangely Mohon Peak board] On 01/04/2014 (Tue 17:59) Brown, Len wrote: > > I've got an eval board with a 1.7GHz Avaton/C2000 that hangs at boot > > shortly after the idle driver registration -- typically 1/2 dozen > > dmesg lines later, around rtc init, or net stack init. > > Paul, > Please boot the failing board with "intel_idle.max_cstate=0" > to disable intel_idle entirely, and then show the C-states > exported by acpi_idle, that predumably, are stable on both boards: > > dmesg | grep idle > grep . /sys/devices/system/cpu/cpu0/cpuidle/*/* > > Then go back and boot with "intel_idle.max_cstate=N" > where N is incremented by 1 until when the system fails > and note the largest N that still works. OK, I kept the failing board on loan, since I expected a reply that would contain "can you try this..." :) I will be able to do the above tomorrow (EST). > > > The interesting part is that a nearly identical board, but with > > different (newer/faster) CPU and newer BIOS doesn't have the hang. > > Possibly an electrical bug in the earlier board. > Maybe they worked around it by disabling a C-state in ACPI > and didn't test upstream Linux? > > I'd be interested in the acpi_idle output above for both the > new and old boards to see if they are exporting different states > on the two boards. Could be ; I can probably get access to the newer one again too, if that will be useful. > > dmidecode isn't useful in this case. The CPUID in /proc/cpuinfo > may be useful if the problem turns out to be associated with > some stepping. The dmidecode info I'd posted indicated that the steppings were unnchanged. I can get the /proc/cpuinfo tomorrow, but I figured the dmidecode stepping info was accurate. Is it not reliable? P. -- > > thanks, > -Len > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/