Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761253AbXERC7S (ORCPT ); Thu, 17 May 2007 22:59:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756188AbXERC7L (ORCPT ); Thu, 17 May 2007 22:59:11 -0400 Received: from moa.IfA.Hawaii.Edu ([128.171.168.48]:36163 "EHLO moa.ifa.hawaii.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755984AbXERC7L (ORCPT ); Thu, 17 May 2007 22:59:11 -0400 Date: Thu, 17 May 2007 17:04:36 -1000 From: Joshua Hoblitt To: Dave Jones Cc: Duane Griffin , Prakash Punnoor , LKML , Daniel Drake , Ed Sweetman Subject: Re: [PATCH] Kconfig powernow-k8 driver should depend on ACPI P-States driver Message-ID: <20070518030436.GB20793@ifa.hawaii.edu> References: <20070516011711.GE15763@ifa.hawaii.edu> <200705162039.02379.prakash@punnoor.de> <20070516204807.GA23751@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="cmJC7u66zC7hs+87" Content-Disposition: inline In-Reply-To: <20070516204807.GA23751@redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2951 Lines: 82 --cmJC7u66zC7hs+87 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable I think it's pretty clear that Dave and Daniel were both correct and that ACPI_PROCESSOR is the correct dependency for multi-socket systems. However, it's worth noting that this dependency seems to be unrelated to SMP support. Ed Sweetman has reported that his single-socket but multi-core system doesn't require ACPI_PROCESSOR for powernow support. I just tried booting 2.6.21 w/o SMP support and w/o ACPI_PROCESSOR on one of my multi-socket/multi-core systems. Sure enough, powernow=20 won't work without ACPI_PROCESSOR: powernow-k8: Found 1 Dual-Core AMD Opteron(tm) Processor 2220 processors (v= ersion 2.00.00) powernow-k8: BIOS error - no PSB or ACPI _PSS objects I suppose this means that the BIOS does something different to enable SMP on a multi-core single socket and multi-socket systems. Anyways, I believe the question that needs to be answered is: is it reasonable for X86_POWERNOW_K8 to select ACPI_PROCESSOR if SMP is set? I'm not sure we can do anything more intelligent unless Kconfig had more knowledge of how the hardware other than just SMP/!SMP. -J -- On Wed, May 16, 2007 at 04:48:07PM -0400, Dave Jones wrote: > On Wed, May 16, 2007 at 08:53:13PM +0100, Duane Griffin wrote: > > On 16/05/07, Prakash Punnoor wrote: > > > Maybe you want to give a hint in the p states driver help text? > >=20 > > I think a hint is the right thing to do, but in the PowerNow! driver > > rather than the p states one. How about adding something like this to > > the X86_POWERNOW_K8 (and X86_POWERNOW_K7?) help text: >=20 > The mobile K7s which had powernow support weren't SMP capable, so they're > irrelevant. >=20 > > "ACPI support is required for non-UP systems and requires ACPI_PROCESS= OR > > to be selected. If ACPI_PROCESSOR is compiled as a module then this > > option must be too in order for ACPI support to be available." >=20 > X86_POWERNOW_K8_ACPI is already 'default y'. I think the problem lies in > that people aren't enabling its dependancy, ACPI_PROCESSOR. >=20 > We want something along the lines of.. >=20 > config X86_POWERNOW_K8_ACPI > bool > if SMP & X86_POWERNOW_K8_ACPI > select ACPI_PROCESSOR >=20 > kconfig language quirks aside.. >=20 >=20 > Dave >=20 > --=20 > http://www.codemonkey.org.uk --cmJC7u66zC7hs+87 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFGTRfEWa2BU+b7tU0RAtHOAKCX1fluHXzkd5pwncYu3mu+a3tfgACgmWM/ 55jkBF6d1AaxLAgOEpQUu3Y= =c7DC -----END PGP SIGNATURE----- --cmJC7u66zC7hs+87-- - 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/