From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from de01egw02.freescale.net (de01egw02.freescale.net [192.88.165.103]) by ozlabs.org (Postfix) with ESMTP id 01F6F67BC9 for ; Wed, 25 Oct 2006 02:09:45 +1000 (EST) Message-ID: <453E3AAC.9040403@freescale.com> Date: Tue, 24 Oct 2006 11:09:16 -0500 From: Scott Wood MIME-Version: 1.0 To: "Rafael J. Wysocki" Subject: Re: pci_set_power_state() failure and breaking suspend References: <1161672898.10524.596.camel@localhost.localdomain> <200610241400.06047.rjw@sisk.pl> In-Reply-To: <200610241400.06047.rjw@sisk.pl> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: Linux Kernel list , linuxppc-dev list , Pavel Machek , Greg KH , linux1394-devel@lists.sourceforge.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Rafael J. Wysocki wrote: > On Tuesday, 24 October 2006 08:54, Benjamin Herrenschmidt wrote: >>However, this raises the question of do we actually want to prevent >>machines to suspend when they have a PCI device that don't have the PCI >>PM capability ? I'm asking that because I can easily imagine that sort >>of construct growing into more drivers (sounds logical if you don't >>think) and I can even imagine somebody thinking it's a good idea to slap >>a __must_check on pci_set_power_state() ... > > > As far as the suspend to RAM is concerned, I don't know. > > For the suspend to disk we can ignore the error if we know that the device > in question won't do anything like a DMA transfer into memory while we're > creating the suspend image. I think it should be ignored for suspend-to-RAM as well; even if a device or two is consuming unnecessary power, it's better than not being able to suspend at all, causing more things to consume unnecessary power. At most, a warning should be issued so the user knows what's going on, and can choose whether to suspend to disk instead (or choose to complain to the device manufacturer). -Scott