Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759444Ab3DAXM5 (ORCPT ); Mon, 1 Apr 2013 19:12:57 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:49668 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759407Ab3DAXMy (ORCPT ); Mon, 1 Apr 2013 19:12:54 -0400 From: "Rafael J. Wysocki" To: Bjorn Helgaas Cc: Martin Mokrejs , ACPI Devel Maling List , Len Brown , Matthew Garrett , Sarah Sharp , LKML , "linux-pci@vger.kernel.org" , Zheng Yan Subject: Re: [Update][PATCH] PCI / PM: Disable runtime PM of PCIe ports Date: Tue, 02 Apr 2013 01:20:27 +0200 Message-ID: <1676539.jiMCqtbGtq@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.9.0-rc4+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <25773480.yrESpQY9Iv@vostro.rjw.lan> References: <2282655.IicBMMa6jN@vostro.rjw.lan> <25773480.yrESpQY9Iv@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2516 Lines: 58 On Monday, April 01, 2013 11:24:37 PM Rafael J. Wysocki wrote: > On Monday, April 01, 2013 02:53:12 PM Bjorn Helgaas wrote: > > On Mon, Apr 1, 2013 at 2:51 PM, Rafael J. Wysocki wrote: > > > On Monday, April 01, 2013 11:34:46 AM Bjorn Helgaas wrote: > > >> [+cc Zheng, who added this with 71a83bd727] > > >> > > >> On Sat, Mar 30, 2013 at 4:38 PM, Rafael J. Wysocki wrote: > > >> > From: Rafael J. Wysocki > > >> > > > >> > The runtime PM of PCIe ports turns out to be quite fragile, as in > > >> > some cases things work while in some other cases they don't and we > > >> > don't seem to have a good way to determine whether or not they are > > >> > going to work in advance. > > >> > > >> Do you have any references to problems encountered when enabling > > >> runtime PM for PCIe ports? That information will be useful to anybody > > >> who wants to take another crack at getting this working. > > > > > > Well, bug 53811 is one example and problems recently reported by > > > Martin are another. Do you want me to dig deeper? > > > > OK, I got this one: > > > > https://bugzilla.kernel.org/show_bug.cgi?id=53811 > > > > Martin has reported a lot of problems lately, and I don't know which > > are related to runtime PM for PCIe ports. I was hoping for a couple > > URLs to put in the changelog so that when somebody gets the itch to > > make this work, they have some useful info to start from. If you > > point me at a specific message, I'll dig up an archive URL for it. > > This is the message in which Martin confirmed that the previous version of > the $subject patch made insert/removal of devices into xHCI ports on his > system work again. > > > Otherwise, I'm afraid we'll just oscillate between "enable PM, find > > bug, disable PM, enable PM, find same bug, disable PM, etc..." > > That's a valid concern, but I think we have an idea about what kind of problems > the runtime PM of PCIe ports may cause to happen (generally, PME and hotplug > notifications may not work as expected). I was thinking about this one in particular: http://marc.info/?l=linux-acpi&m=136460903910718&w=2 Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/