From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S932387Ab2DMUPG (ORCPT <rfc822;w@1wt.eu>);
	Fri, 13 Apr 2012 16:15:06 -0400
Received: from ogre.sisk.pl ([217.79.144.158]:42052 "EHLO ogre.sisk.pl"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1756669Ab2DMUOw (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Fri, 13 Apr 2012 16:14:52 -0400
From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Mikko Vinni <mmvinni@yahoo.com>, Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [linux-pm] "i8042: Can't reactivate AUX port" after s2ram on 3.4-rc2
Date: Fri, 13 Apr 2012 22:19:22 +0200
User-Agent: KMail/1.13.6 (Linux/3.4.0-rc2+; KDE/4.6.0; x86_64; ; )
Cc: "linux-input@vger.kernel.org" <linux-input@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Allen Kay <allen.m.kay@intel.com>,
        Jean Guyader <jean.guyader@eu.citrix.com>,
        Jesse Barnes <jbarnes@virtuousgeek.org>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
References: <1334310754.17013.YahooMailNeo@web161804.mail.bf1.yahoo.com> <201204132118.22074.rjw@sisk.pl> <1334346546.93033.YahooMailNeo@web161806.mail.bf1.yahoo.com>
In-Reply-To: <1334346546.93033.YahooMailNeo@web161806.mail.bf1.yahoo.com>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Message-Id: <201204132219.23106.rjw@sisk.pl>
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Friday, April 13, 2012, Mikko Vinni wrote:
> From: Rafael J. Wysocki:
> 
> > On Friday, April 13, 2012, Mikko Vinni wrote:
> >>  Bug report:
> >>     https://bugzilla.kernel.org/show_bug.cgi?id=43099
> >> 
> >>  Briefly:
> >> 
> >>  After s2ram the touchpad on a HP dv5 laptop doesn't work anymore.
> >> 
> >>  dmesg contains this about the touchpad
> >>  Apr 11 18:00:05 koni kernel: i8042: Can't write CTR while closing AUX 
> > port
> >>  Apr 11 18:00:08 koni kernel: i8042: Can't reactivate AUX port
> >> 
> >> 
> >>  Full log in bugzilla with PCI and i8042 debug turned on.
> >> 
> >>  Bisected to:
> >> 
> >>  commit 26f41062f28de65e11d3cf353e52d0be73442be1
> >>  Author: Kay, Allen M <allen.m.kay@intel.com>
> >>  Date:   Thu Jan 26 10:25:53 2012 -0800
> >> 
> >>      PCI: check for pci bar restore completion and retry
> >>     
> >>      On some OEM systems, pci_restore_state() is called while FLR has not 
> > yet
> >>      completed.  As a result, PCI BAR register restore is not successful.  
> > This fix
> >>      reads back the restored value and compares it with saved value and 
> > re-tries 10
> >>      times before giving up.
> > 
> > Does reverting the above commit on top of the current Linus' tree fix the
> > problem for you?
> 
> 
> It does (at least with the tree from yesterday, 4166fb64593514ad920b7dbd290e0a934b37d24a).

OK, thanks.

Please change that dev_dbg() in pci_restore_state() into dev_info()
and see how many times it gets printed with the commit applied (not reverted).

[Margin note: I think it would make more sense to read the value from
the register _after_ and not before the waiting and I'm not exactly sure why
msleep() is not used.]

Thanks,
Rafael