Re: [PATCH v2 3/9] PCI: preserve dev->subordinate until pci_stop_dev() has been called

On 09/15/2012 01:09 PM, Yinghai Lu wrote:

On Fri, Sep 14, 2012 at 8:05 PM, Jiang Liu [off-list ref] wrote:

quoted

From: Yijing Wang <redacted>

Changeset 2ed168eeb3edec029aa0eca5cb981d6376f931f9 "PCI: Fold stop and
remove helpers into their callers" has changed the behavior when
removing a PCI device.

Previously, for a PCI bridge device with secondary bus, dev->subordinate
is valid when calling PCI bus notification callbacks for
BUS_NOTIFY_ADD_DEVICE/BUS_NOTIFY_DEL_DEVICE events. Now dev->subordinate
has been reset to NULL when calling callbacks for BUS_NOTIFY_DEL_DEVICE
events, which may break some PCI bus notification callbacks.

So revert to the original behavior to keep dev->subordinate valid for
both BUS_NOTIFY_ADD_DEVICE events and BUS_NOTIFY_DEL_DEVICE events.

Signed-off-by: Yijing Wang <redacted>
Signed-off-by: Jiang Liu <redacted>
---
 drivers/pci/remove.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 86a4636..6244956 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c

@@ -79,16 +79,16 @@ void pci_stop_and_remove_bus_device(struct pci_dev *dev)
         * iterator.  Therefore, iterate in reverse so we remove the VFs
         * first, then the PF.
         */
-       if (bus) {
+       if (bus)
                list_for_each_entry_safe_reverse(child, tmp,
                                                 &bus->devices, bus_list)
                        pci_stop_and_remove_bus_device(child);
+       pci_stop_dev(dev);

+       if (bus) {
                pci_remove_bus(bus);
                dev->subordinate = NULL;
        }
-
-       pci_stop_dev(dev);
        pci_destroy_dev(dev);
 }
 EXPORT_SYMBOL(pci_stop_and_remove_bus_device);

for support root bus support with acpi_pci_root (ioapic/iommu) will
need pci_stop_bus_devices()

so I just put those function back...

http://git.kernel.org/?p=linux/kernel/git/yinghai/linux-yinghai.git;a=commitdiff;h=247a40206cf44488f21bc6074cf0ba2805d4d840

Hi Yinghai,
	I will just drop this patch when merging with your pci root bus hotplug work.
	--Gerry