From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933852AbbIVP61 (ORCPT ); Tue, 22 Sep 2015 11:58:27 -0400 Received: from mga09.intel.com ([134.134.136.24]:41073 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932456AbbIVP6Z (ORCPT ); Tue, 22 Sep 2015 11:58:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,573,1437462000"; d="scan'208";a="774605526" Date: Tue, 22 Sep 2015 08:57:30 -0700 From: Jacob Pan To: Austin S Hemmelgarn Cc: Pengyu Ma , "Rafael J. Wysocki" , rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] powercap / RAPL : remove dependency on iosf_mbi Message-ID: <20150922085730.14bafdec@icelake> In-Reply-To: <56015AA0.1020104@gmail.com> References: <1442475101-1872-1-git-send-email-pengyu.ma@windriver.com> <1542119.JQ7HNYzFZu@vostro.rjw.lan> <20150918084356.4bf149a6@yairi> <55FF7DFE.8050906@windriver.com> <20150921143629.4f597e1c@icelake> <56015AA0.1020104@gmail.com> Organization: OTC X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 22 Sep 2015 09:41:52 -0400 Austin S Hemmelgarn wrote: > On 2015-09-21 17:36, Jacob Pan wrote: > > On Mon, 21 Sep 2015 11:48:14 +0800 > > Pengyu Ma wrote: > > > >> > >> > >> On 09/18/2015 11:43 PM, Jacob Pan wrote: > >>> On Fri, 18 Sep 2015 02:09:55 +0200 > >>> "Rafael J. Wysocki" wrote: > >>> > >>>> On Thursday, September 17, 2015 03:31:41 PM Pengyu Ma wrote: > >>>>> iosf_mbi is supported on Quark, Braswell, Baytrail and some Atom > >>>>> SoC, but RAPL is not limited to these SoC, it supports almost > >>>>> Intel CPUs. Remove this dependece to make RAPL support more > >>>>> Intel CPUs. > >>>>> > >>>>> Please select IOSF_MBI on Atom SoCs. > >>>>> > >>> Unlike Quark, I don't think we want to or do differentiate Atom > >>> from other x86 at compile time. IOSF driver can be compiled as a > >>> module also, therefore RAPL driver needs this explicit dependency > >>> at compile time. > >> As commit had exported iosf_mbi to let user use it. > >> > >> commit aa8e4f22ab7773352ba3895597189b8097f2c307 > >> Author: David E. Box > >> Date: Wed Aug 27 14:40:39 2014 -0700 > >> > >> x86/iosf: Add Kconfig prompt for IOSF_MBI selection > >> > >> > >> While selecting IOSF_MBI is preferred, it does mean carrying extra > >> code on non-SoC architectures. > >> > >> We can NOT force user to build in iosf_mbi if they want use RAPL on > >> haswell/broadwell/skylake. > >> And RAPL can be compiled and worked well on > >> haswell/broadwell/skylake without IOSF_MBI. > >> RAPL is really NOT depended on IOSF_MBI. > >> > > True for haswell/broadwell/skylake platforms. But if we want binary > > compatibility for Atom and Core, I can' see how simply removing the > > dependency would work, unless we have runtime detection of IOSF. > So make RAPL select IOSF instead of depending on it, add something to > the RAPL help text saying that IOSF is needed for it to work on > SoC's, and make IOSF=y in the defconfig. > > This way, people who just turn on RAPL support should get IOSF, > whereas people like me who actually build custom kernels for each > system we own aren't forced to include yet more code that is 100% > useless for us. > If you build a custom kernel for Core with RAPL, your kernel would still "select" IOSF which is not needed. right? > It's also worth noting that most of the people who care about binary > compatibility for a wide variety of chips in one kernel (read as > 'distro maintainers') will be turning IOSF on anyway, because it's > needed for other things on chips that have it to work right as well. > > true. no issue for that case. > >> Pengyu > >>>>> Signed-off-by: Pengyu Ma > >>>> Jacob? > >>>> > >>>>> --- > >>>>> drivers/powercap/Kconfig | 2 +- > >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>>>> > >>>>> diff --git a/drivers/powercap/Kconfig b/drivers/powercap/Kconfig > >>>>> index 85727ef..a7c81b5 100644 > >>>>> --- a/drivers/powercap/Kconfig > >>>>> +++ b/drivers/powercap/Kconfig > >>>>> @@ -17,7 +17,7 @@ if POWERCAP > >>>>> # Client driver configurations go here. > >>>>> config INTEL_RAPL > >>>>> tristate "Intel RAPL Support" > >>>>> - depends on X86 && IOSF_MBI > >>>>> + depends on X86 > >>>>> default n > >>>>> ---help--- > >>>>> This enables support for the Intel Running Average > >>>>> Power Limit (RAPL) > >>>>> > >>> [Jacob Pan] > >> > > > > [Jacob Pan] > > -- > > 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/ > > > > [Jacob Pan]