From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933038AbZJLR6x (ORCPT ); Mon, 12 Oct 2009 13:58:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933022AbZJLR6v (ORCPT ); Mon, 12 Oct 2009 13:58:51 -0400 Received: from cantor2.suse.de ([195.135.220.15]:58484 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932192AbZJLR6t (ORCPT ); Mon, 12 Oct 2009 13:58:49 -0400 Date: Mon, 12 Oct 2009 10:37:42 -0700 From: Greg KH To: Dmitry Torokhov Cc: =?iso-8859-1?Q?=C9ric?= Piel , Linux Kernel Mailing List , linux-input@vger.kernel.org Subject: Re: [REGRESSION] "bind" a device to a driver doesn't not work anymore Message-ID: <20091012173742.GD10557@suse.de> References: <4AD120F2.3020606@tremplin-utc.net> <20091011030029.GA6526@suse.de> <200910112135.29384.dmitry.torokhov@gmail.com> <4AD31709.4000103@tremplin-utc.net> <20091012144458.GA1326@suse.de> <20091012154553.GA7996@core.coreip.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20091012154553.GA7996@core.coreip.homeip.net> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 12, 2009 at 08:45:54AM -0700, Dmitry Torokhov wrote: > On Mon, Oct 12, 2009 at 07:44:58AM -0700, Greg KH wrote: > > On Mon, Oct 12, 2009 at 01:46:17PM +0200, Éric Piel wrote: > > > Op 12-10-09 06:35, Dmitry Torokhov schreef: > > > > On Saturday 10 October 2009 08:00:29 pm Greg KH wrote: > > > >> On Sun, Oct 11, 2009 at 02:04:02AM +0200, ?ric Piel wrote: > > > >>> Hello, > > > >>> > > > >>> After a suspend, I used to do this (to get the PS2 keyboard working > > > >>> again), and it used to work fine: > > > >>> echo -n "i8042" > /sys/bus/platform/drivers/i8042/unbind ; sleep 1 ; echo > > > >>> -n "i8042" > /sys/bus/platform/drivers/i8042/bind > > > >>> > > > >>> Unfortunately since 2.6.32-rc1, the unbind works fine, but the bind > > > >>> returns a "no such device" error now (and the binding is not done). After > > > >>> that, additional unbinds also report the error. I think 2.6.31 worked > > > >>> fine. Any idea what's going wrong? > > > >> Odd. Any chance you can run 'git bisect' to figure out which patch > > > >> might have caused it? > > > > > > > > I8042 has been converted to use platform_driver_probe() - we are creating > > > > platform device and platform driver together, there is no chance that some > > > > other device might be driven by i8042 driver. > > > I haven't finished bisecting, but indeed, the problem seemed to converge > > > toward this patch. > > > > > > > > > > Eric, do you still need to fiddle with i8042 to get your keyboard working with > > > > 2.6.32-rc3? We need to make sure that resube works without users needing to > > > > mess with bind/unbind. > > > Yes, the keyboard doesn't work after the first resume from ram (the > > > later resumes do work). I haven't tried any special option to the i8042 > > > driver. This is on a HP 2510, in 64 bits. > > > > > > Indeed, it would be great to fix this root problem! Is there any bug > > > report opened to work on this? > > > > > > However, currently the first problem is that unbind works, while bind > > > doesn't. Which means anyone doing an unbind will have keyboard and mouse > > > lost until the next reboot. That's rather bad because it has been > > > recommended for a long time to have this kind of script at resume: > > > http://intertrusion.com/files/hp-s2ram.patch > > > http://en.opensuse.org/Pm-utils > > > > > > So at least, unbind should fail as well as bind. > > > > Ah, I bet I know why bind fails... Yeah, the i8042_platform_device is > > never freed up in the i8042_remove() function in > > drivers/input/serio/i8042.c, so when you try to register it again, it > > fails. > > > > Huh? Platform device and driver are created in i8042_init() and removed > in i8042_exit(); i8042_remove() is a remove() method of the platform > driver so it never should be freeing the platform device. Ah, but you do not have the ability to allow a bind to ever happen again. I guess that's fine if you don't want that to happen. And for platform devices, it's kind of difficult now that I think about it some more. > The issue is that with platform drivers using i8042_driver_probe() the > probe frunction is discarded afterwards so the driver can't be bound to > anything after initialization has been completed; however unbinding > through 'unbind' attribute still works (once). You may recall a thread > with me and David arguing about it a couple of weeks ago... Yeah, I remember that... At least we now know the problem. Just rmmod and insmod the module to unbind/bind and everyone will be happy :) thanks, greg k-h