From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761148AbXGDAf3 (ORCPT ); Tue, 3 Jul 2007 20:35:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760888AbXGDAef (ORCPT ); Tue, 3 Jul 2007 20:34:35 -0400 Received: from cavan.codon.org.uk ([217.147.92.49]:45627 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760855AbXGDAee (ORCPT ); Tue, 3 Jul 2007 20:34:34 -0400 Date: Wed, 4 Jul 2007 01:34:24 +0100 From: Matthew Garrett To: Robert Hancock Cc: Alan Stern , linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org Message-ID: <20070704003424.GA30958@srcf.ucam.org> References: <468AE700.7080102@shaw.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <468AE700.7080102@shaw.ca> User-Agent: Mutt/1.5.12-2006-07-14 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@codon.org.uk Subject: Re: [linux-pm] [PATCH] Remove process freezer from suspend to RAM pathway X-SA-Exim-Version: 4.2.1 (built Tue, 20 Jun 2006 01:35:45 +0000) X-SA-Exim-Scanned: Yes (on vavatch.codon.org.uk) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 03, 2007 at 06:17:04PM -0600, Robert Hancock wrote: > Matthew Garrett wrote: > >Leave the process blocked and defer any i/o until after resume. Why does > >it need to be any more complicated than that? > > It gets complicated when this has to be added and TESTED in EVERY > driver. The implied contract for drivers previously was that their > device would not get accessed after it was suspended until it had been > resumed first. This proposed change violates that. No, that's only ever been true for ACPI systems. It's never been true elsewhere, and it won't be true for anything implementing any sort of runtime power management. > I don't think this sort of handling is something that individual drivers > should have to deal with (at least not ones that are part of a framework > like USB, libata, etc.) I'd agree there. Driver midlayers (where they exist) are the appropriate place to handle this. -- Matthew Garrett | mjg59@srcf.ucam.org