Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030473AbaDBV6p (ORCPT ); Wed, 2 Apr 2014 17:58:45 -0400 Received: from mga11.intel.com ([192.55.52.93]:55928 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030460AbaDBV6o convert rfc822-to-8bit (ORCPT ); Wed, 2 Apr 2014 17:58:44 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,782,1389772800"; d="scan'208";a="513212264" From: "Brown, Len" To: "Gortmaker, Paul (Wind River)" CC: "Wysocki, Rafael J" , Arne Bockholdt , Jiang Liu , "x86@kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: Regression in intel_idle on Avaton/Rangely Mohon Peak board Thread-Topic: Regression in intel_idle on Avaton/Rangely Mohon Peak board Thread-Index: AQHPTdaFVLQYzxSM7EqDlaR4cHXJtZr9TPjAgAHpVACAAAhvgP//n59w Date: Wed, 2 Apr 2014 21:58:42 +0000 Message-ID: <1A7043D5F58CCB44A599DFD55ED4C948452FDABF@FMSMSX106.amr.corp.intel.com> References: <533B0288.2020304@windriver.com> <1A7043D5F58CCB44A599DFD55ED4C948452FD582@FMSMSX106.amr.corp.intel.com> <533C6C90.3000708@windriver.com> <20140402203130.GA22525@windriver.com> In-Reply-To: <20140402203130.GA22525@windriver.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.1.200.106] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > [ 0.840668] intel_idle: lapic_timer_reliable_states 0x2 vs. > [ 0.877528] intel_idle: lapic_timer_reliable_states 0xffffffff This means CPUID.ARAT is set for the new board, and not set for the old board. You can observe that also in /proc/cpuinfo flags where you will likely also find a visible stepping difference between these two boards. Bring-up Avoton had ARAT disabled, and also had broken deep C-states. It looks like that is what your old board has. Throw it away and use only production steppings. If you are stuck w/ pre-production hardware, then you need to manually modify upstream Linux to make it happy -- since upstream Linux only cares about production hardware. 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/