From mboxrd@z Thu Jan 1 00:00:00 1970 From: Len Brown Subject: Re: [PATCH] Enable bit 11 in _PDC to advertise hw coord Date: Fri, 06 Feb 2009 23:10:03 -0500 (EST) Message-ID: References: <20090202195717.GA24510@linux-os.sc.intel.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from vms173005pub.verizon.net ([206.46.173.5]:20655 "EHLO vms173005pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751067AbZBGEKI (ORCPT ); Fri, 6 Feb 2009 23:10:08 -0500 Received: from localhost.localdomain ([96.237.168.40]) by vms173005.mailsrvcs.net (Sun Java(tm) System Messaging Server 6.3-7.04 (built Sep 26 2008; 32bit)) with ESMTPA id <0KEO00KYOGWSZHE2@vms173005.mailsrvcs.net> for linux-acpi@vger.kernel.org; Fri, 06 Feb 2009 22:10:05 -0600 (CST) In-reply-to: <20090202195717.GA24510@linux-os.sc.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Pallipadi, Venkatesh" Cc: linux-acpi@vger.kernel.org, Jens Axboe , Chris Mason applied thanks, -- Len Brown, Intel Open Source Technology Center On Mon, 2 Feb 2009, Pallipadi, Venkatesh wrote: > > 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(+) > > 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 | \ > -- > 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 >