From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f174.google.com ([209.85.223.174]:43945 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753264Ab2IHWBc (ORCPT ); Sat, 8 Sep 2012 18:01:32 -0400 Message-ID: <504BC038.2050608@lwfinger.net> Date: Sat, 08 Sep 2012 17:01:28 -0500 From: Larry Finger MIME-Version: 1.0 To: Alan Stern CC: "Rafael J. Wysocki" , Bjorn Helgaas , linux-pci@vger.kernel.org, LKML , =?UTF-8?B?5p2O5pyd5piO?= , Linux PM list , Huang Ying Subject: Re: Question about failure in PCI power-state change References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: On 09/08/2012 04:50 PM, Alan Stern wrote: > On Sat, 8 Sep 2012, Rafael J. Wysocki wrote: > >> On Saturday, September 08, 2012, Bjorn Helgaas wrote: >>> +cc Rafael, Huang, linux-pm >>> >>> On Fri, Sep 7, 2012 at 3:44 PM, Larry Finger wrote: >>>> Hi, >>>> >>>> On occasion when I unload and reload driver rtl8192ce, I get the message >>>> >>>> "Refused to change power state, currently in D3" >>>> >>>> I added additional info to the printk and discovered that it was trying to >>>> change to state D0. The problem seems to occur when I have made a >>>> connection, unloaded the driver, and reloaded it. If I do not make a >>>> connection before unloading, then the problem is a lot less likely. >>>> >>>> This is with kernel 3.6-rc4 from wireless-testing. A Google search shows >>>> that the problem is usually due to suspend/resume difficulties, but this >>>> machine has not been suspended. >>>> >>>> I would appreciate any help that you might give in solving this issue. >> >> I think writing "on" to the /sys/devices/.../power/control attribute of the device >> in question would help. > > Are you suggesting that this particular wireless adapter is unable to > return to D0 from D3? > > Larry, what happens if you try the suspend & resume your system while > there's a connection? Does a similar error occur during the resume? After I sent this request, I found an error in the removal process for this particular adapter, which I suspect is the real source of the problem. That difficulty is only found on the new variant of the card - the older one is OK. I think the problem is that the adapter is left in some ill-defined state that can only be cleared by doing a power reset. In that state, it is unable to return to D0. This box has never been able to suspend/resume, thus I cannot answer the other question. Thanks to all that responded. Once I clean up the other error, I will recontact the list if the D3 => D0 problem persists. Larry