From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31CE3C2D0DA for ; Fri, 27 Dec 2019 10:36:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01FE720882 for ; Fri, 27 Dec 2019 10:36:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726579AbfL0Kgw (ORCPT ); Fri, 27 Dec 2019 05:36:52 -0500 Received: from cloudserver094114.home.pl ([79.96.170.134]:49569 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726354AbfL0Kgv (ORCPT ); Fri, 27 Dec 2019 05:36:51 -0500 Received: from 79.184.255.87.ipv4.supernova.orange.pl (79.184.255.87) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.320) id d2f5f766b7eab7f5; Fri, 27 Dec 2019 11:36:49 +0100 From: "Rafael J. Wysocki" To: Kai-Heng Feng Cc: bhelgaas@google.com, rafael.j.wysocki@intel.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI/PM: Report runtime wakeup is not supported if bridge isn't bound to driver Date: Fri, 27 Dec 2019 11:36:49 +0100 Message-ID: <1948783.ToaVGCCZch@kreacher> In-Reply-To: <20191227092405.29588-1-kai.heng.feng@canonical.com> References: <20191227092405.29588-1-kai.heng.feng@canonical.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, December 27, 2019 10:24:05 AM CET Kai-Heng Feng wrote: > We have a Pericom USB add-on card that has three USB controller > functions 06:00.[0-2], connected to bridge device 05:03.0, which is > connected to another bridge device 04:00.0: > > -[0000:00]-+-00.0 > +-1c.6-[04-06]----00.0-[05-06]----03.0-[06]--+-00.0 > | +-00.1 > | \-00.2 > > When bridge device (05:03.0) and all three USB controller functions > (06:00.[0-2]) are runtime suspended, they don't get woken up by plugging > USB devices into the add-on card. > > This is because the pcieport driver failed to probe on 04:00.0, since > the device supports neither legacy IRQ, MSI nor MSI-X. Because of that, > there's no native PCIe PME can work for devices connected to it. But in that case the PME driver (drivers/pci/pcie/pme.c) should not bind to the port in question, so the "can_wakeup" flag should not be set for the devices under that port. > So let's correctly report runtime wakeup isn't supported when any of > PCIe bridges isn't bound to pcieport driver. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205981 > Signed-off-by: Kai-Heng Feng > --- > drivers/pci/pci.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 951099279192..ca686cfbd65e 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -2493,6 +2493,18 @@ bool pci_dev_run_wake(struct pci_dev *dev) > if (!pci_pme_capable(dev, pci_target_state(dev, true))) > return false; > > + /* If any upstream PCIe bridge isn't bound to pcieport driver, there's > + * no IRQ for PME. > + */ > + if (pci_is_pcie(dev)) { > + while (bus->parent) { > + if (!bus->self->driver) > + return false; > + > + bus = bus->parent; > + } > + } > + So it looks like device_can_wakeup() returns 'true' for this device, but it should return 'false'. Do you know why the "can_wakeup" flag is set for it? > if (device_can_wakeup(&dev->dev)) > return true; > > Moreover, even if the native PME is not supported, there can be an ACPI GPE (or equivalent) that triggers when WAKE# is asserted by one of the PCIe devices connected to it, so the test added by this patch cannot be used in general.