From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Renninger Subject: Re: Core i7 & C-States Date: Fri, 19 Nov 2010 01:59:31 +0100 Message-ID: <201011190159.32152.trenn@suse.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from cantor.suse.de ([195.135.220.2]:38590 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760062Ab0KSA7e (ORCPT ); Thu, 18 Nov 2010 19:59:34 -0500 In-Reply-To: Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Greg Oliver Cc: linux-acpi@vger.kernel.org On Wednesday 17 November 2010 09:34:43 pm Greg Oliver wrote: > Hi, > > This is my first motherboard with ACPI issues, so I am in uncharted > water. It is an intel board, so no overclocking, etc. Reading through > as much as I can this morning, I have hit the wall. I have > disassembled all of my [DS]SDTs, and will attach them with a dmesg as > this seems to be the normal request from the archives. > > About the issue though - > > If I enable either/or C-STATES/C2-STATES, How do you enable them? I expect you disable them (disabling these does vary depending whether intel_idle or acpi_idle is used, see below)? > the system will freeze on > boot. Disabling them both the system runs fine, but I would obviously > like the power savings if possible. Now I know this BIOS has some > issues as some PCI devices (when disabled in the BIOS) still get > partially enumerated and assigned IRQs on the bus as well, but that > does not concern me as much as the power. The latest update to the > BIOS from intel is installed. Interesting. Which kernel are you running? With latest kernel intel_idle should be used for C-states on such a new CPU and it will totally ignore ACPI C-state information. If it works, it's due to ACPI tables. You can check here: cat /sys/devices/system/cpu/cpuidle/current_driver That should show acpi_idle if processor.ko driver is used and ACPI tables are used or intel_idle. > This is the only ACPI error I get from dmesg currently though: > > ACPI Warning: Incorrect checksum in table [SSDT] - 3F, should be 91 > (20090903/tbutils-314) Probably irrelvant to C-states. > > I have also booted with "acpi.debug_layer=0xFFFFFFFF > acpi.debug_level=0x80000000" appended to my kernel cmdline and I am > unsure why, but even though the system showed all debugs enabled in > /sys, I did not receive any extra debug messages in dmesg!?!? For C-states this debug facility does not help much. If intel_idle also freezes the machine, you should open a bug on bugzilla.kernel.org, please add me and Len Brown to CC then. Thomas