Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936247AbdCXOz5 (ORCPT ); Fri, 24 Mar 2017 10:55:57 -0400 Received: from mail.kernel.org ([198.145.29.136]:36526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936116AbdCXOzp (ORCPT ); Fri, 24 Mar 2017 10:55:45 -0400 Date: Fri, 24 Mar 2017 09:55:36 -0500 From: Bjorn Helgaas To: Long Li Cc: "K. Y. Srinivasan" , Haiyang Zhang , Bjorn Helgaas , Stephen Hemminger , devel@linuxdriverproject.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Long Li Subject: Re: [PATCH 1/2 v5] pci-hyperv: properly handle pci bus remove Message-ID: <20170324145536.GB25380@bhelgaas-glaptop.roam.corp.google.com> References: <1490306290-6382-1-git-send-email-longli@exchange.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1490306290-6382-1-git-send-email-longli@exchange.microsoft.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2440 Lines: 80 On Thu, Mar 23, 2017 at 02:58:10PM -0700, Long Li wrote: > From: Long Li > > hv_pci_devices_present is called in hv_pci_remove when we remove a PCI > device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove, > the bus is already removed before the call, so we don't need to rescan the > bus in the workqueue scheduled from hv_pci_devices_present. > > By introducing status hv_pcibus_removed, we can avoid this situation. > > Signed-off-by: Long Li > Reported-by: Xiaofeng Wang > Acked-by: K. Y. Srinivasan Applied both patches to pci/host-hv for v4.12, thanks! They both applied perfectly :) > --- > drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c > index ada9856..39fafda 100644 > --- a/drivers/pci/host/pci-hyperv.c > +++ b/drivers/pci/host/pci-hyperv.c > @@ -350,6 +350,7 @@ enum hv_pcibus_state { > hv_pcibus_init = 0, > hv_pcibus_probed, > hv_pcibus_installed, > + hv_pcibus_removed, > hv_pcibus_maximum > }; > > @@ -1504,13 +1505,24 @@ static void pci_devices_present_work(struct work_struct *work) > put_pcichild(hpdev, hv_pcidev_ref_initial); > } > > - /* Tell the core to rescan bus because there may have been changes. */ > - if (hbus->state == hv_pcibus_installed) { > + switch(hbus->state) { > + case hv_pcibus_installed: > + /* > + * Tell the core to rescan bus > + * because there may have been changes. > + */ > pci_lock_rescan_remove(); > pci_scan_child_bus(hbus->pci_bus); > pci_unlock_rescan_remove(); > - } else { > + break; > + > + case hv_pcibus_init: > + case hv_pcibus_probed: > survey_child_resources(hbus); > + break; > + > + default: > + break; > } > > up(&hbus->enum_sem); > @@ -2185,6 +2197,7 @@ static int hv_pci_probe(struct hv_device *hdev, > hbus = kzalloc(sizeof(*hbus), GFP_KERNEL); > if (!hbus) > return -ENOMEM; > + hbus->state = hv_pcibus_init; > > /* > * The PCI bus "domain" is what is called "segment" in ACPI and > @@ -2348,6 +2361,7 @@ static int hv_pci_remove(struct hv_device *hdev) > pci_stop_root_bus(hbus->pci_bus); > pci_remove_root_bus(hbus->pci_bus); > pci_unlock_rescan_remove(); > + hbus->state = hv_pcibus_removed; > } > > hv_pci_bus_exit(hdev); > -- > 2.7.4 >