From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755636Ab0EQVnX (ORCPT ); Mon, 17 May 2010 17:43:23 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:38745 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751894Ab0EQVnW convert rfc822-to-8bit (ORCPT ); Mon, 17 May 2010 17:43:22 -0400 From: "Rafael J. Wysocki" To: Brian Swetland Subject: Re: [PATCH 0/8] Suspend block api (version 7) Date: Mon, 17 May 2010 23:44:46 +0200 User-Agent: KMail/1.12.4 (Linux/2.6.34-rjw; KDE/4.3.5; x86_64; ; ) Cc: Arve =?utf-8?q?Hj=C3=B8nnev=C3=A5g?= , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <1273810273-3039-1-git-send-email-arve@android.com> <201005172240.35742.rjw@sisk.pl> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Message-Id: <201005172344.46222.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 17 May 2010, Brian Swetland wrote: > On Mon, May 17, 2010 at 1:40 PM, Rafael J. Wysocki wrote: > > On Monday 17 May 2010, Arve Hjønnevåg wrote: > >> > >> It should get out of that loop as soon as someone blocks suspend. If > >> someone is constantly aborting suspend without using a suspend blocker > >> it will be very inefficient, but it should still work. > > > > Well, the scenario I have in mind is the following. Someone wants to check > > the feature and simply writes "opportunistic" to /sys/power/policy and "mem" to > > /sys/power/state without any drivers or apps that use suspend blockers. > > > > How in that case is the system supposed to break out of the suspend-resume loop > > resulting from this? I don't see right now, because the main blocker is > > inactive, there are no other blockers that can be activated and it is next to > > impossible to write to /sys/power/state again. > > I guess we could set a flag when a suspend blocker is registered and > refuse to enter opportunistic mode if no blockers have ever been > registered. > > It does seem like extra effort to go through to handle a "don't do > that" type scenario (entering into opportunistic suspend without > anything that will prevent it). I agree, but I think it's necessary. We shouldn't add interfaces that hurt users if not used with care. Thanks, Rafael