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PCI: acpiphp: remove all functions in slot, even without ACPI _EJx 

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 slot (including all functions of the 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@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Amos Kong 2012-05-23 10:20:35 -06:00 committed by Bjorn Helgaas
parent 638f293307
commit ce29ca3ea4
2 changed files with 34 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/pci/hotplug/acpiphp_glue.c
View File

@ -878,6 +878,24 @@ 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;
struct pci_dev *ret = NULL;
down_read(&pci_bus_sem);
list_for_each_entry(dev, &bus->devices, bus_list)
if (PCI_SLOT(dev->devfn) == slot->device) {
ret = pci_dev_get(dev);
break;
}
up_read(&pci_bus_sem);
return ret;
}
/**
* disable_device - disable a slot
* @slot: ACPI PHP slot
@ -902,18 +920,22 @@ 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) {

2
drivers/pci/search.c
View File

@ -15,6 +15,8 @@
#include "pci.h"
DECLARE_RWSEM(pci_bus_sem);
EXPORT_SYMBOL_GPL(pci_bus_sem);
/*
* find the upstream PCIe-to-PCI bridge of a PCI device
* if the device is PCIE, return NULL