From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH v2 4/6] ACPI: ARM: exclude DMI calls Date: Mon, 25 Nov 2013 17:45:52 +0000 Message-ID: <20131125174552.GA7417@srcf.ucam.org> References: <1385080915-23430-1-git-send-email-al.stone@linaro.org> <528F9C65.7010302@linaro.org> <4285284.l8TssFvumi@vostro.rjw.lan> <528FF15C.4060300@linaro.org> <20131123163854.GA1817@srcf.ucam.org> <1AE640813FDE7649BE1B193DEA596E880248D1A8@SHSMSX101.ccr.corp.intel.com> <20131125153016.GA3243@srcf.ucam.org> <52938C3F.20905@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:56957 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754958Ab3KYRqC (ORCPT ); Mon, 25 Nov 2013 12:46:02 -0500 Content-Disposition: inline In-Reply-To: <52938C3F.20905@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Al Stone Cc: "Zheng, Lv" , "Rafael J. Wysocki" , Olof Johansson , Rob Herring , "linux-acpi@vger.kernel.org" , Linaro Patches , "linaro-kernel@lists.linaro.org" , "linaro-acpi@lists.linaro.org" On Mon, Nov 25, 2013 at 10:43:27AM -0700, Al Stone wrote: > On 11/25/2013 08:30 AM, Matthew Garrett wrote: > >Is ACPI_REDUCED_HARDWARE supposed to indicate support for the reduced > >hardware profile, or that the platform *only* implements the reduced > >hardware profile? > > From what I can see in ACPICA, ACPI_REDUCED_HARDWARE indicates the > platform *only* implements the reduced hardware profile. This *seems* > to be consistent with the specification -- see 3.11.1, second bullet, > for example: Ok, so a kernel built without ACPI_REDUCED_HARDWARE would still support the reduced hardware profile? > ...if by "not supported" one takes that to mean "does not exist when > compiled." I can look at the ACPICA code again, just the same; perhaps > there is some reasonable way to at least select one or the other at boot > as the first step, and then allow switching between modes as a later > step. I don't think you'd ever want to switch after init time. There's a flag in the FADT that indicates whether a system is implementing the reduced hardware profile or not. -- Matthew Garrett | mjg59@srcf.ucam.org