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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>
This commit is contained in:
Yuji Shimada 2009-04-03 16:41:46 +09:00 committed by Jesse Barnes
parent 7eb93b175d
commit 296ccb086d
5 changed files with 10 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/pci/bus.c
View File

@ -184,7 +184,7 @@ void pci_enable_bridges(struct pci_bus *bus)
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->subordinate) {
if (atomic_read(&dev->enable_cnt) == 0) {
if (!pci_is_enabled(dev)) {
retval = pci_enable_device(dev);
pci_set_master(dev);
}

2
drivers/pci/pci-sysfs.c
View File

@ -148,7 +148,7 @@ static ssize_t is_enabled_store(struct device *dev,
return -EPERM;
if (!val) {
if (atomic_read(&pdev->enable_cnt) != 0)
if (pci_is_enabled(pdev))
pci_disable_device(pdev);
else
result = -EIO;

4
drivers/pci/pci.c
View File

@ -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);
}

2
drivers/pci/setup-bus.c
View File

@ -144,7 +144,7 @@ static void pci_setup_bridge(struct pci_bus *bus)
struct pci_bus_region region;
u32 l, bu, lu, io_upper16;
if (!pci_is_root_bus(bus) && bus->is_added)
if (pci_is_enabled(bridge))
return;
dev_info(&bridge->dev, "PCI bridge, secondary bus %04x:%02x\n",

5
include/linux/pci.h
View File

@ -674,6 +674,11 @@ int __must_check pci_reenable_device(struct pci_dev *);
int __must_check pcim_enable_device(struct pci_dev *pdev);
void pcim_pin_device(struct pci_dev *pdev);
static inline int pci_is_enabled(struct pci_dev *pdev)
{
return (atomic_read(&pdev->enable_cnt) > 0);
}
static inline int pci_is_managed(struct pci_dev *pdev)
{
return pdev->is_managed;