Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751685Ab3F0BU0 (ORCPT ); Wed, 26 Jun 2013 21:20:26 -0400 Received: from mail-ie0-f176.google.com ([209.85.223.176]:62844 "EHLO mail-ie0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751383Ab3F0BUZ (ORCPT ); Wed, 26 Jun 2013 21:20:25 -0400 MIME-Version: 1.0 In-Reply-To: <1372177330-28013-3-git-send-email-mika.westerberg@linux.intel.com> References: <1372177330-28013-1-git-send-email-mika.westerberg@linux.intel.com> <1372177330-28013-3-git-send-email-mika.westerberg@linux.intel.com> Date: Wed, 26 Jun 2013 18:20:24 -0700 X-Google-Sender-Auth: uEVnYilTQKXVuhQuZbQ1H7g4JJU Message-ID: Subject: Re: [PATCH 2/6] PCI: acpiphp: enable_device(): rescan even if no new devices on slot From: Yinghai Lu To: Mika Westerberg Cc: Greg Kroah-Hartman , Bjorn Helgaas , "Rafael J. Wysocki" , Jesse Barnes , John Ronciak , Miles J Penner , Bruce Allan , "Kirill A. Shutemov" , Heikki Krogerus , Linux Kernel Mailing List , "linux-pci@vger.kernel.org" , "the arch/x86 maintainers" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3633 Lines: 88 On Tue, Jun 25, 2013 at 9:22 AM, Mika Westerberg wrote: > From: "Kirill A. Shutemov" > > pci_scan_slot() returns number of new devices connected *directly* > connected to the slot. Current enable_device() checks the return value > and stops if it doesn't see a new device. > > In Thunderbolt chaining case the new device can be deeper in hierarchy, so > do the rescan anyway. > > Because of that we must make sure that pcibios_resource_survey_bus() and > check_hotplug_bridge() get called only for a just found bus and not the > ones already added to the system. Failure to do so will lead to resource > conflicts. > > Signed-off-by: Kirill A. Shutemov > Signed-off-by: Mika Westerberg > --- > drivers/pci/hotplug/acpiphp_glue.c | 18 +++++++----------- > 1 file changed, 7 insertions(+), 11 deletions(-) > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > index b983e29..80a6ea1 100644 > --- a/drivers/pci/hotplug/acpiphp_glue.c > +++ b/drivers/pci/hotplug/acpiphp_glue.c > @@ -685,18 +685,13 @@ static int __ref enable_device(struct acpiphp_slot *slot) > struct pci_dev *dev; > struct pci_bus *bus = slot->bridge->pci_bus; > struct acpiphp_func *func; > - int num, max, pass; > + int max, pass; > LIST_HEAD(add_list); > > list_for_each_entry(func, &slot->funcs, sibling) > acpiphp_bus_add(func); > > - num = pci_scan_slot(bus, PCI_DEVFN(slot->device, 0)); > - if (num == 0) { > - /* Maybe only part of funcs are added. */ > - dbg("No new device found\n"); > - goto err_exit; > - } > + pci_scan_slot(bus, PCI_DEVFN(slot->device, 0)); > > max = acpiphp_max_busnr(bus); > for (pass = 0; pass < 2; pass++) { > @@ -707,8 +702,11 @@ static int __ref enable_device(struct acpiphp_slot *slot) > dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) { > max = pci_scan_bridge(bus, dev, max, pass); > if (pass && dev->subordinate) { > - check_hotplug_bridge(slot, dev); > - pcibios_resource_survey_bus(dev->subordinate); > + if (!dev->subordinate->is_added) { > + check_hotplug_bridge(slot, dev); > + pcibios_resource_survey_bus( > + dev->subordinate); > + } No, this change will totally disable calling check_hotplug_bridge/pcibios_resource_survey_bus() as pci_scan_bridge/pci_scan_child_bus will set dev->subordinate->is_added... Please note: recently is_added setting is moved early before pci_bus_add_devices... > __pci_bus_size_bridges(dev->subordinate, > &add_list); > } > @@ -742,8 +740,6 @@ static int __ref enable_device(struct acpiphp_slot *slot) > } > } > > - > - err_exit: > return 0; > } > > -- > 1.8.3.1 > -- 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/