From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932740AbcCKQdx (ORCPT ); Fri, 11 Mar 2016 11:33:53 -0500 Received: from mga04.intel.com ([192.55.52.120]:7420 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932567AbcCKQdu convert rfc822-to-8bit (ORCPT ); Fri, 11 Mar 2016 11:33:50 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,321,1455004800"; d="scan'208";a="908098736" From: "Chen, Yu C" To: Matt Fleming 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 Thread-Topic: [PATCH][RFC,v4] ACPI / PM: Introduce efi poweroff for HW-full platforms without _S5 Thread-Index: AQHRe3RlqjzIKmiap0+aItZGSTsxWp9T3+0AgACOePA= Date: Fri, 11 Mar 2016 16:33:46 +0000 Message-ID: <36DF59CE26D8EE47B0655C516E9CE640286D442A@shsmsx102.ccr.corp.intel.com> References: <1457687133-3730-1-git-send-email-yu.c.chen@intel.com> <20160311155546.GJ15775@codeblueprint.co.uk> In-Reply-To: <20160311155546.GJ15775@codeblueprint.co.uk> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiZDQ4NzAxMDAtYjJiNy00MWRkLThiYTQtMzBhNDkyMzViNGNjIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6Im51bXhMXC95cGJ1MUppQlFScER0TUFcL2lwSzV2aEYycjNaVm9QTitZcDV5ND0ifQ== x-ctpclassification: CTP_IC x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Matt, > -----Original Message----- > From: Matt Fleming [mailto:matt@codeblueprint.co.uk] > Sent: Friday, March 11, 2016 11:56 PM > 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 05:05:33PM, Chen Yu wrote: > > The problem is Linux registers pm_power_off = efi_power_off only if we > > are in hardware reduced mode. Actually, what we also want is to do > > this when ACPI S5 is simply not supported on non-legacy platforms. > > That should handle both the HW reduced mode, and the HW-full mode > > where the DSDT fails to supply an _S5 object. > > > > This patch introduces pm_power_off_default which would be used by > > pm_power_off if nothing else is available. And in this case we > > leverage efi power off to be this role. However since efi power off > > may not be stable enough thus in order not to interfere with other > > poweroff path, we only make a minimum enhancement for x86 in > > native_machine_power_off. > > > > Suggested-by: Len Brown > > Signed-off-by: Chen Yu > > --- > > v4: > > - Since in v3 efi_poweroff_required() is not guaranteed to run > > after all of the other code that may register alternative > > power off handling, add the pm_power_off_default that would > > be used by pm_power_off if nothing else is available. > > v3: > > - Only assign pm_power_off to efi_power_off when there are no > > other pm_power_off registered at that time, in case other > > commponents would like to customize their own implementation. > > --- > > v2: > > - Convert the acpi_no_s5 to a global bool variable in sleep.c and > > add a declaration to include/linux/acpi.h. > > --- > > arch/x86/kernel/reboot.c | 3 +++ > > arch/x86/platform/efi/quirks.c | 5 +++++ > > drivers/acpi/sleep.c | 7 +++++++ > > drivers/firmware/efi/reboot.c | 8 ++++++++ > > include/linux/acpi.h | 1 + > > include/linux/efi.h | 1 + > > include/linux/pm.h | 1 + > > kernel/reboot.c | 1 + > > 8 files changed, 27 insertions(+) > > Couple of things, > > 1) I'm still waiting for an answer to my question on whether > platforms without _S5 that need EFI reset actually exist. You > said they "might" exist, which makes this all sound very > speculative. It is not obvious to me that this approach makes > sense. 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) > > 2) In v4 you're modifying the generic EFI reboot code and should Cc > other developers who might care, e.g. the arm64 folks. I've Cc'd > them now. OK, thanks. yu