PCI: Setup disabled bridges even if buses are added

This patch sets up disabled bridges even if buses have already been
added.

pci_assign_unassigned_resources is called after buses are added.
pci_assign_unassigned_resources calls pci_bus_assign_resources.
pci_bus_assign_resources calls pci_setup_bridge to configure BARs of
bridges.

Currently pci_setup_bridge returns immediately if the bus have already
been added. So pci_assign_unassigned_resources can't configure BARs of
bridges that were added in a disabled state; this patch fixes the issue.

On logical hot-add, we need to prevent the kernel from re-initializing
bridges that have already been initialized. To achieve this,
pci_setup_bridge returns immediately if the bridge have already been
enabled.

We don't need to check whether the specified bus is a root bus or not.
pci_setup_bridge is not called on a root bus, because a root bus does
not have a bridge.

The patch adds a new helper function, pci_is_enabled. I made the
function name similar to pci_is_managed. The codes which use
enable_cnt directly are changed to use pci_is_enabled.

Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Yuji Shimada <shimada-yxb@necst.nec.co.jp>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 445fb6f7ea3f..16fd0d4c3166 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -844,7 +844,7 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
  */
 int pci_reenable_device(struct pci_dev *dev)
 {
-        if (atomic_read(&dev->enable_cnt))
+        if (pci_is_enabled(dev))
                 return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1);
         return 0;
 }
@@ -1042,7 +1042,7 @@ static void do_pci_disable_device(struct pci_dev *dev)
  */
 void pci_disable_enabled_device(struct pci_dev *dev)
 {
-        if (atomic_read(&dev->enable_cnt))
+        if (pci_is_enabled(dev))
                 do_pci_disable_device(dev);
 }