Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759292Ab0FJOjz (ORCPT ); Thu, 10 Jun 2010 10:39:55 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:36957 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1759259Ab0FJOjw (ORCPT ); Thu, 10 Jun 2010 10:39:52 -0400 Date: Thu, 10 Jun 2010 10:39:50 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: david@lang.hm cc: =?ISO-8859-15?Q?Arve_Hj=F8nnev=E5g?= , , Alan Cox , Florian Mickler , Peter Zijlstra , Brian Swetland , "H. Peter Anvin" , LKML , Neil Brown , James Bottomley , Linux PM , Thomas Gleixner , Linux OMAP Mailing List , Linus Torvalds , Ingo Molnar , Felipe Balbi , Arjan van de Ven Subject: Re: [linux-pm] suspend blockers & Android integration In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1146 Lines: 28 On Wed, 9 Jun 2010 david@lang.hm wrote: > why could the suspend blocker process see all events, but the power > manager process not see the events? > > have the userspace talk to the power manager the way it does to the > suspend blocker now and what's the difference? > > effectivly think s/suspend blocker/power manager/ (with the power manager > doing all the other things that are proposed instead of grabbing the > wakelock), the difference should be hidden to the rest of userspace. > > what am I missing here? The main difference is that with a userspace power manager, programs have to tell the power manager whenever they open or close a wakeup-capable device file (and send it a copy of the file descriptor). With an in-kernel implementation these extra steps aren't needed, because of course kernel drivers already know when their device files are opened or closed. Alan Stern -- 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/