On Tue, May 22, 2012 at 9:35 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > From: Amos Kong <kongjianjun@xxxxxxxxx> > > When we add a device with acpiphp, we enumerate all functions in the > slot with pci_scan_slot(), regardless of whether they have associated > ACPI methods such as _EJ0. > > When removing the device, we previously removed only the functions > with those ACPI methods. This patch makes the remove symmetric with the > add: we remove all functions in the slot, whether they have associated > ACPI methods or not. > > With qemu-kvm and SeaBIOS, we can build a multi-function device where > only function 0 has _EJ0 and _ADR (see bugzilla below). Removing and > re-adding that device works correctly with Windows guests. This patch > makes it also work in Linux guests. > > [bhelgaas: restructure loop iteration, pull out of slot->funcs loop] > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=43219 > Signed-off-by: Amos Kong <kongjianjun@xxxxxxxxx> > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > --- > drivers/pci/hotplug/acpiphp_glue.c | 39 +++++++++++++++++++++++++++--------- > 1 files changed, 29 insertions(+), 10 deletions(-) > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > index c8f9991..9aff4f0 100644 > --- a/drivers/pci/hotplug/acpiphp_glue.c > +++ b/drivers/pci/hotplug/acpiphp_glue.c > @@ -878,6 +878,21 @@ static void disable_bridges(struct pci_bus *bus) > } > } > > +/* return first device in slot, acquiring a reference on it */ > +static struct pci_dev *dev_in_slot(struct acpiphp_slot *slot) > +{ > + struct pci_bus *bus = slot->bridge->pci_bus; > + struct pci_dev *dev; > + > + down_read(&pci_bus_sem); > + list_for_each_entry(dev, &bus->devices, bus_list) > + if (PCI_SLOT(dev->devfn) == slot->device) > + return pci_dev_get(dev); > + up_read(&pci_bus_sem); Do you need to keep that pci_bus_sem operation pair on return path? > + > + return NULL; > +} > + > /** > * disable_device - disable a slot > * @slot: ACPI PHP slot > @@ -902,18 +917,22 @@ static int disable_device(struct acpiphp_slot *slot) > (u32)1, NULL, NULL); > func->bridge = NULL; > } > + } > > - pdev = pci_get_slot(slot->bridge->pci_bus, > - PCI_DEVFN(slot->device, func->function)); > - if (pdev) { > - pci_stop_bus_device(pdev); > - if (pdev->subordinate) { > - disable_bridges(pdev->subordinate); > - pci_disable_device(pdev); > - } > - __pci_remove_bus_device(pdev); > - pci_dev_put(pdev); > + /* > + * enable_device() enumerates all functions in this device via > + * pci_scan_slot(), whether they have associated ACPI hotplug > + * methods (_EJ0, etc.) or not. Therefore, we remove all functions > + * here. > + */ > + while ((pdev = dev_in_slot(slot))) { > + pci_stop_bus_device(pdev); > + if (pdev->subordinate) { > + disable_bridges(pdev->subordinate); > + pci_disable_device(pdev); > } > + __pci_remove_bus_device(pdev); > + pci_dev_put(pdev); > } > > list_for_each_entry(func, &slot->funcs, sibling) { > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
