On Tue, Mar 13, 2012 at 12:26 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Mon, Mar 12, 2012 at 8:44 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
>> On Sat, Mar 10, 2012 at 12:00 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
>>> It will rediscover removed pci root buses.
>>>
>>> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
>>> ---
>>> drivers/pci/pci-sysfs.c | 2 ++
>>> 1 files changed, 2 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
>>> index 4d122cb..fc0a7de 100644
>>> --- a/drivers/pci/pci-sysfs.c
>>> +++ b/drivers/pci/pci-sysfs.c
>>> @@ -284,6 +284,7 @@ msi_bus_store(struct device *dev, struct device_attribute *attr,
>>>
>>> #ifdef CONFIG_HOTPLUG
>>> static DEFINE_MUTEX(pci_remove_rescan_mutex);
>>> +void __weak arch_pci_root_rescan(void) { }
>>> static ssize_t bus_rescan_store(struct bus_type *bus, const char *buf,
>>> size_t count)
>>> {
>>> @@ -295,6 +296,7 @@ static ssize_t bus_rescan_store(struct bus_type *bus, const char *buf,
>>>
>>> if (val) {
>>> mutex_lock(&pci_remove_rescan_mutex);
>>> + arch_pci_root_rescan();
>>> while ((b = pci_find_next_bus(b)) != NULL)
>>> pci_rescan_bus(b);
>>> mutex_unlock(&pci_remove_rescan_mutex);
>>
>> This is gross. We used to rescan every previously-discovered PCI root bus.
>>
>> Now, we do the same, plus:
>> 1) Scan the ACPI namespace for PCI host bridges, adding and scanning
>> any we haven't seen before, and
>> 2) scan domain 0, buses 0 - pcibios_last_bus, looking for any we
>> haven't seen before.
>
> to have /sys/bus/pci/scan_root again?
Host bridges are not PCI devices, so scanning for them is not a PCI
operation. It should not be in the /sys/bus/pci hierarchy.
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
