Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751675AbbEGQz1 (ORCPT ); Thu, 7 May 2015 12:55:27 -0400 Received: from 251.110.2.81.in-addr.arpa ([81.2.110.251]:44720 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750859AbbEGQzZ (ORCPT ); Thu, 7 May 2015 12:55:25 -0400 Date: Thu, 7 May 2015 17:54:56 +0100 From: One Thousand Gnomes To: "Rafael J. Wysocki" Cc: Tomeu Vizoso , Chirantan Ekbote , Olof Johansson , John Stultz , Bastien Nocera , Linux Kernel Mailing List , snanda@chromium.org, Linux PM list Subject: Re: A desktop environment[1] kernel wishlist Message-ID: <20150507175456.51376473@lxorguk.ukuu.org.uk> In-Reply-To: <26037972.gZDpmonflh@vostro.rjw.lan> References: <1413881397.30379.7.camel@hadess.net> <2236285.G0hRnmeVkc@vostro.rjw.lan> <26037972.gZDpmonflh@vostro.rjw.lan> Organization: Intel Corporation X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.27; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1736 Lines: 35 On Tue, 05 May 2015 14:31:26 +0200 > For example, when you wake up from S3 on ACPI-based systems, the best you > can get is what devices have generated the wakeup events, but there's > no input available from that (like you won't know which key has been > pressed). You may not get that even. You may only know what GPEs have > caused the wakeup to happen and they may be shared. > > For PCI wakeup, the wakeup event may be out of band. You need to walk > the hierarchy and check the PME status bits to identify the wakeup device > and then you need to be careful enough not to reset it while putting into > D0 for the input data associated with the event to be available. I'm not > sure how many device/driver combinations this actually works for. > > For USB wakeup, you get the wakeup event from the controller which may be > a PCI device. Getting to the USB device itself from there requires some > work and even then the device may not "remember" what exactly happened. > > Further, if you wake up via the PC keyboard from suspend-to-idle, the > wakeup key code is not available, the only thing you know is that the > interrupts has occured (that may be changed, but it's how the current > code works). It's probably got to change, otherwise once machines get able to sleep between keypresses it's going to suck every time you pause and think for a minute then begin typing. Remember display being off for suspend is purely a limitation of most current display panels. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/