> -----Original Message----- > From: Bjorn Helgaas [mailto:helgaas@xxxxxxxxxx] > Sent: Thursday, March 16, 2017 1:07 PM > To: Long Li <longli@xxxxxxxxxxxxx> > Cc: KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang > <haiyangz@xxxxxxxxxxxxx>; Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; > devel@xxxxxxxxxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/2 v4] pci-hyperv: properly handle pci bus remove > > On Tue, Feb 28, 2017 at 02:19:45AM +0000, Long Li wrote: > > 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 <longli@xxxxxxxxxxxxx> > > Reported-by: Xiaofeng Wang <xiaofwan@xxxxxxxxxx> > > Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > > This didn't apply for me because saving it to a file resulted in some encoded > file with "=3D" instead of "=". I see that mutt is smart enough to deal with > that in this reply, so there's probably a way for it to decode it when saving to > a file, but I don't know it. > > I tried to apply it by hand, but the hunk in hv_pci_remove() doesn't match > the context. I think your patch is based on something previous to > 17978524a636 ("PCI: hv: Fix hv_pci_remove() for hot-remove"). Please > refresh the patch so it applies to my "master" branch (currently v4.11-rc1). > > Also, the "default: break;" case below is redundant and can be removed. > > So I'll wait for your updated versions of both these patches. > > > --- > > 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 a8deeca..4a37598 100644 > > --- a/drivers/pci/host/pci-hyperv.c > > +++ b/drivers/pci/host/pci-hyperv.c > > @@ -348,6 +348,7 @@ enum hv_pcibus_state { > > hv_pcibus_init = 0, > > hv_pcibus_probed, > > hv_pcibus_installed, > > + hv_pcibus_removed, > > hv_pcibus_maximum > > }; > > > > @@ -1481,13 +1482,24 @@ 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; > > ^ This is redundant. I found it still needs "default:break", or it will give a compiler warning: drivers/pci/host/pci-hyperv.c: In function 'pci_devices_present_work': drivers/pci/host/pci-hyperv.c:1510:2: warning: enumeration value 'hv_pcibus_removed' not handled in switch [-Wswitch] switch(hbus->state) { ^ drivers/pci/host/pci-hyperv.c:1510:2: warning: enumeration value 'hv_pcibus_maximum' not handled in switch [-Wswitch] > > > } > > > > up(&hbus->enum_sem); > > @@ -2163,6 +2175,7 @@ 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 @@ > > -2305,6 +2318,7 @@ 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; > > } > > > > ret = hv_send_resources_released(hdev); > > -- > > 1.8.5.6
