Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752631AbdFTCAl (ORCPT ); Mon, 19 Jun 2017 22:00:41 -0400 Received: from mail-io0-f178.google.com ([209.85.223.178]:33931 "EHLO mail-io0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752320AbdFTCAZ (ORCPT ); Mon, 19 Jun 2017 22:00:25 -0400 MIME-Version: 1.0 In-Reply-To: References: <1979543.KIEJ8uyRaT@aspire.rjw.lan> <3454366.uzaJljlWGm@aspire.rjw.lan> <3689795.xuIczRHZsl@aspire.rjw.lan> <2026371.DVJN39QYJi@aspire.rjw.lan> From: Linus Torvalds Date: Tue, 20 Jun 2017 10:00:18 +0800 X-Google-Sender-Auth: sp5snpZxvPSUOnnMKY6B_gM7cT0 Message-ID: Subject: Re: [PATCH v2 3/3] ACPI / sleep: EC-based wakeup from suspend-to-idle on recent Dell systems To: "Rafael J. Wysocki" Cc: "Rafael J. Wysocki" , Linux PM , Linux ACPI , Andy Shevchenko , Darren Hart , LKML , Srinivas Pandruvada , Mika Westerberg , Mario Limonciello , Tom Lanyon , =?UTF-8?B?SsOpcsO0bWUgZGUgQnJldGFnbmU=?= Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1429 Lines: 30 On Tue, Jun 20, 2017 at 9:13 AM, Rafael J. Wysocki wrote: > > My understanding is that Windows uses the ACPI_FADT_LOW_POWER_S0 flag. > It generally enables non-S3 suspend/resume when this flag is set and > it doesn't touch S3 then. Keeping the EC GPE (and other GPEs for that > matter) enabled over suspend/resume is part of that if my > understanding is correct. > > During suspend we generally disable all GPEs that are not expected to > generate wakeup events in order to avoid spurious wakeups, but we can > try to keep them enabled if ACPI_FADT_LOW_POWER_S0 is set. That will > reduce the ugliness, but the cost may be more energy used while > suspended on some systems. I think trying to do something similar to what windows does is likely the right thing, since that is (sadly) the only thing that tends to get extensive testing still. Of course, different versions of Windows then probably do different things, but I guess ACPI_FADT_LOW_POWER_S0 ends up being a good sign of "new machine designed for windows 10", so it's probably a good thing to trigger that behavior on. So I suspect it's worth testing, particularly if we're going to be in the situation that a lot of machines are going to do this going forward (ie the "all Dell" may end up being more than just Dell too? Dell usually doesn't do particularly odd and out-of-the-norm design choices like some vendors do). Linus