From patchwork Mon Feb 2 19:57:18 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: venkip X-Patchwork-Id: 5099 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n12JvNV1012811 for ; Mon, 2 Feb 2009 19:57:23 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753140AbZBBT5W (ORCPT ); Mon, 2 Feb 2009 14:57:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753188AbZBBT5W (ORCPT ); Mon, 2 Feb 2009 14:57:22 -0500 Received: from mga14.intel.com ([143.182.124.37]:61297 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753140AbZBBT5W (ORCPT ); Mon, 2 Feb 2009 14:57:22 -0500 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga102.ch.intel.com with ESMTP; 02 Feb 2009 11:57:18 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.37,366,1231142400"; d="scan'208";a="106253930" Received: from linux-os.sc.intel.com ([172.25.110.8]) by azsmga001.ch.intel.com with ESMTP; 02 Feb 2009 11:57:18 -0800 Received: by linux-os.sc.intel.com (Postfix, from userid 47009) id 10F4A28006; Mon, 2 Feb 2009 11:57:18 -0800 (PST) Date: Mon, 2 Feb 2009 11:57:18 -0800 From: "Pallipadi, Venkatesh" To: Len Brown Cc: linux-acpi@vger.kernel.org, Jens Axboe , Chris Mason Subject: [PATCH] Enable bit 11 in _PDC to advertise hw coord Message-ID: <20090202195717.GA24510@linux-os.sc.intel.com> Mime-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.4.1i Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Bit 11 in intel PDC definitions is meant for OS capability to handle hardware coordination of P-states. In Linux we have always supported hwardware coordination of P-states. Just let the BIOSes know that we support it, by setting this bit. Some BIOSes use this bit to choose between hardware or software coordination and without this change below, BIOSes switch to software coordination, which is not very optimal in terms of power consumption and extra wakeups from idle. Signed-off-by: Venkatesh Pallipadi --- include/acpi/pdc_intel.h | 2 ++ 1 file changed, 2 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-2.6/include/acpi/pdc_intel.h =================================================================== --- linux-2.6.orig/include/acpi/pdc_intel.h 2009-01-20 16:11:20.000000000 -0800 +++ linux-2.6/include/acpi/pdc_intel.h 2009-02-02 10:32:06.000000000 -0800 @@ -14,6 +14,7 @@ #define ACPI_PDC_SMP_T_SWCOORD (0x0080) #define ACPI_PDC_C_C1_FFH (0x0100) #define ACPI_PDC_C_C2C3_FFH (0x0200) +#define ACPI_PDC_SMP_P_HWCOORD (0x0800) #define ACPI_PDC_EST_CAPABILITY_SMP (ACPI_PDC_SMP_C1PT | \ ACPI_PDC_C_C1_HALT | \ @@ -22,6 +23,7 @@ #define ACPI_PDC_EST_CAPABILITY_SWSMP (ACPI_PDC_SMP_C1PT | \ ACPI_PDC_C_C1_HALT | \ ACPI_PDC_SMP_P_SWCOORD | \ + ACPI_PDC_SMP_P_HWCOORD | \ ACPI_PDC_P_FFH) #define ACPI_PDC_C_CAPABILITY_SMP (ACPI_PDC_SMP_C2C3 | \