[PATCH] PCI: Only call pci_stop_bus_device() one time for childrendevices during removing

From: Yinghai Lu
Date: Wed Nov 23 2011 - 00:07:32 EST



During debugging pcie hotplug with SRIOV with pcie switch, found
pci_stop_bus_device() are called several times for some children devices.

Current pci_remove_bus_device() will call pci_stop_bus_device() at first.
and then use remove_behind_bridge() to call pci_stop_bus_device() for children
devices. But pci_stop_bus_device() already include depth first to stop children.
So We can remove unnecessary calling in pci_remove_behind_bridge() for children.

The patch change original pci_remove_bus_device() to __pci_remove_bus_device(), and
it only do remove work, and new pci_remove_bus_device will call
pci_stop_bus_device() one time, and then call __pci_remove_bus_device().

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
drivers/pci/remove.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

Index: linux-2.6/drivers/pci/remove.c
===================================================================
--- linux-2.6.orig/drivers/pci/remove.c
+++ linux-2.6/drivers/pci/remove.c
@@ -89,9 +89,8 @@ EXPORT_SYMBOL(pci_remove_bus);
* device lists, remove the /proc entry, and notify userspace
* (/sbin/hotplug).
*/
-void pci_remove_bus_device(struct pci_dev *dev)
+static void __pci_remove_bus_device(struct pci_dev *dev)
{
- pci_stop_bus_device(dev);
if (dev->subordinate) {
struct pci_bus *b = dev->subordinate;

@@ -102,6 +101,11 @@ void pci_remove_bus_device(struct pci_de

pci_destroy_dev(dev);
}
+void pci_remove_bus_device(struct pci_dev *dev)
+{
+ pci_stop_bus_device(dev);
+ __pci_remove_bus_device(dev);
+}

/**
* pci_remove_behind_bridge - remove all devices behind a PCI bridge
@@ -117,7 +121,7 @@ void pci_remove_behind_bridge(struct pci

if (dev->subordinate)
list_for_each_safe(l, n, &dev->subordinate->devices)
- pci_remove_bus_device(pci_dev_b(l));
+ __pci_remove_bus_device(pci_dev_b(l));
}

static void pci_stop_bus_devices(struct pci_bus *bus)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/