From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933328AbcASWJq (ORCPT ); Tue, 19 Jan 2016 17:09:46 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:54775 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S932252AbcASWJh (ORCPT ); Tue, 19 Jan 2016 17:09:37 -0500 From: "Rafael J. Wysocki" To: Bjorn Helgaas , Qipeng Zha Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, bhelgaas@google.com, mika.westerberg@intel.com, Qi Zheng , "Rafael J. Wysocki" Subject: Re: [PATCH 1/2] PCI/PM: Revert "PCI/PM: Drop unused runtime PM support code for PCIe ports" Date: Tue, 19 Jan 2016 23:10:20 +0100 Message-ID: <41526334.QosPv6IFu0@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.4.0; KDE/4.11.5; x86_64; ; ) In-Reply-To: <20160119215234.GH14080@localhost> References: <1452868065-96999-1-git-send-email-qipeng.zha@intel.com> <20160119215234.GH14080@localhost> 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 On Tuesday, January 19, 2016 03:52:34 PM Bjorn Helgaas wrote: > [+cc Rafael, author of fe9a743a2601] > > On Fri, Jan 15, 2016 at 10:27:44PM +0800, Qipeng Zha wrote: > > This reverts commit fe9a743a2601 ("PCI/PM: Drop unused runtime > > PM support code for PCIe ports"). To support PCIe ports > > runtime PM for Intel Broxton platform. > > This changelog is not as useful as it could be. It's true that this > reverts fe9a743a2601, but what's important is that this adds support > code for runtime PM of PCIe ports, so that should be mentioned first. > > The fe9a743a2601 changelog says "If we are to support runtime PM of > PCIe ports, it will have to be done in a different way most likely > anyway." I don't know what Rafael had in mind there, but we certainly > need to ask him before adding it back the same way it was. Thanks! The previous approach had a few problems that showed up in testing and that's why the code was first disabled and then removed from the kernel. We can't re-enable it or those problems will show up again. I have not looked at adding PCIe port runtime PM support in a cleaner way yet, but it is on my radar. Thanks, Rafael