Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030927AbcCQOji (ORCPT ); Thu, 17 Mar 2016 10:39:38 -0400 Received: from mail-wm0-f43.google.com ([74.125.82.43]:38025 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030741AbcCQOja (ORCPT ); Thu, 17 Mar 2016 10:39:30 -0400 Date: Thu, 17 Mar 2016 14:39:26 +0000 From: Matt Fleming To: "Chen, Yu C" Cc: "linux-acpi@vger.kernel.org" , "linux-pm@vger.kernel.org" , "Rafael J. Wysocki" , Len Brown , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Zhang, Rui" , "linux-efi@vger.kernel.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Ard Biesheuvel , Mark Salter Subject: Re: [PATCH][RFC,v4] ACPI / PM: Introduce efi poweroff for HW-full platforms without _S5 Message-ID: <20160317143926.GL2619@codeblueprint.co.uk> References: <1457687133-3730-1-git-send-email-yu.c.chen@intel.com> <20160311155546.GJ15775@codeblueprint.co.uk> <36DF59CE26D8EE47B0655C516E9CE640286D442A@shsmsx102.ccr.corp.intel.com> <20160314200033.GG2619@codeblueprint.co.uk> <36DF59CE26D8EE47B0655C516E9CE640286D5713@shsmsx102.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <36DF59CE26D8EE47B0655C516E9CE640286D5713@shsmsx102.ccr.corp.intel.com> User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1989 Lines: 48 On Wed, 16 Mar, at 05:59:29AM, Chen, Yu C wrote: > Hi Matt, > > > -----Original Message----- > > From: Matt Fleming [mailto:matt@codeblueprint.co.uk] > > Sent: Tuesday, March 15, 2016 4:01 AM > > To: Chen, Yu C > > Cc: linux-acpi@vger.kernel.org; linux-pm@vger.kernel.org; Rafael J. Wysocki; > > Len Brown; Thomas Gleixner; Ingo Molnar; H. Peter Anvin; Zhang, Rui; linux- > > efi@vger.kernel.org; x86@kernel.org; linux-kernel@vger.kernel.org; Ard > > Biesheuvel; Mark Salter > > Subject: Re: [PATCH][RFC,v4] ACPI / PM: Introduce efi poweroff for HW-full > > platforms without _S5 > > > > On Fri, 11 Mar, at 04:33:46PM, Chen, Yu C wrote: > > > > > > There is a future Base-IA platform, we are planning to skip > > > implementing the SLP_TYP register and the S5 object. (already there > > > will be no S3 and no S4) > > > > Cool. This is really valuable information that should go into the commit > > message. > > > > Because if this is the rationale for the change, I don't see why we'd need to > > provide the default stuff. Instead we should just enforce EFI reboot, and > > only add the pm_poweroff_default hook if there is an explicit user in the > > future, IMO. > > Do you mean the patch v3 make sense > https://patchwork.kernel.org/patch/8514751/ > and we should use efi power off as our first choice, if there is no _S5 available(no acpi_power_off), > even there is a customized poweroff(driver provided, eg)? Unless someone can point to a platform driver that is in the upstream kernel where this is actually a problem, the answer is: yes. For that matter, unless someone can do the same for pm_power_off overriding efi_reboot() (which on x86 would only happen for ACPI HW-reduced platforms), I would be much prefer the original patch, where you had, bool efi_poweroff_reqired(voi) { return acpi_gbl_reduced_hardware || acpi_no_s5; } since you've already explained that this change won't break legacy platforms that are missing _S5 (if any even exist in the wild).