From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Stone Subject: Re: [PATCH v2 4/6] ACPI: ARM: exclude DMI calls Date: Fri, 22 Nov 2013 17:05:48 -0700 Message-ID: <528FF15C.4060300@linaro.org> References: <1385080915-23430-1-git-send-email-al.stone@linaro.org> <528F9C65.7010302@linaro.org> <4285284.l8TssFvumi@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ie0-f177.google.com ([209.85.223.177]:37382 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755467Ab3KWAFu (ORCPT ); Fri, 22 Nov 2013 19:05:50 -0500 Received: by mail-ie0-f177.google.com with SMTP id tp5so3240434ieb.22 for ; Fri, 22 Nov 2013 16:05:50 -0800 (PST) In-Reply-To: <4285284.l8TssFvumi@vostro.rjw.lan> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" , Olof Johansson Cc: Rob Herring , linux-acpi@vger.kernel.org, Linaro Patches , "linaro-kernel@lists.linaro.org" , linaro-acpi@lists.linaro.org On 11/22/2013 04:15 PM, Rafael J. Wysocki wrote: > On Friday, November 22, 2013 10:53:09 AM Olof Johansson wrote: >> On Fri, Nov 22, 2013 at 10:03 AM, Al Stone wrote: >>> On 11/22/2013 06:25 AM, Rob Herring wrote: >>>> >>>> On Thu, Nov 21, 2013 at 6:41 PM, wrote: >>>>> >>>>> From: Al Stone >>>>> >>>>> Modified #ifdef so that DMI is not used on ARM platforms which >>>>> are currently implementing ACPI reduced HW mode. >>>> >>>> >>>> It is really not allowed or is optional? There are various people that >>>> want DMI tables on ARM. >>>> >>>> Rob >>> >>> >>> True. DMI is optional. I see it as orthogonal to >>> reduced HW mode; I have to hope that when DMI patches >>> are forthcoming they'll do the right thing here. >>> >>> Is there a better way to do this in the #if ? >> >> >> Doing all of these things at compile time seems odd, shouldn't it be >> handled at runtime? What happens when someone wants to build a kernel >> that boots both on the reduced hw mode platforms and regular ones? > > I agree. > > My suggestion would be to harden dmi_check_system() so that it works > if DMI is not present (if it doesn't already). > > Thanks! > I agree -- runtime would be better. For dmi_check_system(), that can be done and I'll look into that. I'll also go double check the rest of my #ifdefs and see if I can remove any more of them from the Linux side of the ACPI code. For reduced hardware mode, however, I have to rely on the underlying ACPICA reference implementation to behave properly. Right now, ACPICA relies on compile time changes to implement either reduced HW mode or legacy mode so I have to follow suit. When I looked at making ACPICA change behavior at runtime, the changes became more and more invasive. Since x86/ia64 depend on ACPICA to behave also, that seemed a far more dangerous approach to me. -- ciao, al ----------------------------------- Al Stone Software Engineer Linaro Enterprise Group al.stone@linaro.org -----------------------------------