From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Youquan,Song" Subject: Re: [PATCH]acpi c-states: Fix ACPI C3 is wrongly mapped to C2 Date: Sat, 12 Dec 2009 18:55:49 -0500 Message-ID: <20091212235549.GA7753@youquan-linux.bj.intel.com> References: <20091212181442.GA22832@youquan-linux.bj.intel.com> <20091212142727.GA6867@comet.dominikbrodowski.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mga07.intel.com ([143.182.124.22]:27097 "HELO azsmga101.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with SMTP id S933599AbZLMBgq (ORCPT ); Sat, 12 Dec 2009 20:36:46 -0500 Content-Disposition: inline In-Reply-To: <20091212142727.GA6867@comet.dominikbrodowski.net> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Dominik Brodowski Cc: "Youquan,Song" , lenb@kernel.org, venkatesh.pallipadi@intel.com, kent.liu@intel.com, chaohong.guo@intel.com, youquan.song@intel.com, linux-acpi@vger.kernel.org On Sat, Dec 12, 2009 at 03:27:27PM +0100, Dominik Brodowski wrote: > On Sat, Dec 12, 2009 at 01:14:42PM -0500, Youquan,Song wrote: > > On Nehalem-EX, CPU C3 is mapped to ACPI C3, but C-states information in /proc > > and /sys are conflicting with ACPI C2 mapping and confused user. > > Well, isn't the "type" only losely related to the C-state number anyway, if > you have more than 3 states? That's true, if CPU has more 3 states such as C3, C6, C7, there are all mapped to ACPI C3. But the current situation is that if platform does NOT support ACPI C2, the user interface /sys show us ACPI C2 is supported which actual is ACPI C3. As you know, ACPI C3 and ACPI C2 have much different, such as: BUS SNOOP or not, ACPI C3 has better power saving etc. we should not mix them. Thanks. -Youquan