From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: A reference implementation of PCI suspend/resume? Date: Tue, 17 May 2005 11:10:46 +0200 Message-ID: <200505171110.47030.rjw@sisk.pl> References: <9F77D654ED40B74CA79E5A60B97A087B0310DCD4@sd-exchange.sdesigns.com> <20050516151937.63b37fbb@cosmic.amd.com> <200505161726.42479.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============89825189572565645==" Return-path: In-Reply-To: <200505161726.42479.david-b@pacbell.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: linux-pm@lists.osdl.org Cc: David Brownell List-Id: linux-pm@vger.kernel.org --===============89825189572565645== Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Hi, On Tuesday, 17 of May 2005 02:26, David Brownell wrote: > On Monday 16 May 2005 2:19 pm, Jordan Crouse wrote: > > On Mon, 16 May 2005 16:16:06 -0400 > > "Adam Belay" wrote: > > > > > b.) You're assuming every device has its own interrupt. This may not > > > be the case. Let's say one device was sharing interrupts with a few > > > other devices... > > > > I ran into this very problem a while back on 2.4. On my platform, the > > EHCI and OCHI host controllers share an interrupt. ... > > > > Now, granted that particular scenario is a corner case, and the PCI > > hardware should have been configured better, but it shows that you > > can't assume that any given interrupt handler will only be called with > > active hardware underneath. > > Very true, and that's part of why drivers/usb/core/hcd-pci.c frees > IRQs during suspend, and reclaims them later. > > AFAICT that code is the most generic PCI suspend/resume code now > available ... since it's got to work with dozens of different > implementations of EHCI, OHCI, and UHCI; with widely varying > BIOS versions and bugs; and where not all controllers support > the PCI PM extensions. > > Note the wierdnesses there ... cases where the PCI API calls are > wierdly asymmetric, and where "swsusp" can really bork things > by entering bizarre "resume" paths. Could you please have a look at http://bugzilla.kernel.org/show_bug.cgi?id=4416 There seems to be a problem with OHCI and EHCI drivers wrt suspend/resume (swsusp) in the current -mm on that box. Greets, Rafael -- - Would you tell me, please, which way I ought to go from here? - That depends a good deal on where you want to get to. -- Lewis Carroll "Alice's Adventures in Wonderland" --===============89825189572565645== Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline --===============89825189572565645==--