From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH] usb: Add support for runtime power management of the hcd Date: Thu, 12 Nov 2009 14:51:22 +0000 Message-ID: <20091112145121.GB6709@srcf.ucam.org> References: <200911112324.58076.rjw@sisk.pl> <20091112003312.GA27572@srcf.ucam.org> <200911120841.11263.oliver@neukum.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:37529 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752891AbZKLOvX (ORCPT ); Thu, 12 Nov 2009 09:51:23 -0500 Content-Disposition: inline In-Reply-To: <200911120841.11263.oliver@neukum.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Oliver Neukum Cc: Alan Stern , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, USB list On Thu, Nov 12, 2009 at 08:41:11AM +0100, Oliver Neukum wrote: > Am Donnerstag, 12. November 2009 01:33:12 schrieb Matthew Garrett: > > On Wed, Nov 11, 2009 at 06:09:24PM -0500, Alan Stern wrote: > > > That's okay. There's no harm in trying to enable remote wakeup on a > > > device which doesn't support it. > > > > There's harm if we're using the ability to generate remote waleups as a > > condition for whether we can perform runtime pm on the device... > > That I would consider backwards. If the user enables runtime power management > of a device, he has to live with remote wakeup being enabled. At most > the kernel might resume and switch off remote wakeup on the device, > but we might also leave this to user space. My point was that if we don't have remote wakeup support at runtime, we can't enable runtime PM of the device. So we need to be able to distinguish between runtime remote wakeup and system sleep remote wakeup. -- Matthew Garrett | mjg59@srcf.ucam.org