Re: [PATCH v2 06/29] x86/PCI: convert to pci_create_root_bus() andpci_scan_root_bus()

From: Yinghai Lu
Date: Fri Oct 14 2011 - 16:39:51 EST


On 10/14/2011 01:32 PM, Bjorn Helgaas wrote:


>>> int node;
>>> @@ -353,11 +349,18 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
>>> memcpy(bus->sysdata, sd, sizeof(*sd));
>>> kfree(sd);
>>> } else {
>>> - bus = pci_create_bus(NULL, busnum, &pci_root_ops, sd);
>>> - if (bus) {
>>> - get_current_resources(device, busnum, domain, bus);
>>> - bus->subordinate = pci_scan_child_bus(bus);
>>> + INIT_LIST_HEAD(&resources);
>>> + get_current_resources(device, busnum, domain, &resources);
>>> + if (!pci_use_crs) {
>>> + pci_free_resource_list(&resources);
>>> + x86_pci_root_bus_resources(busnum, &resources);
>>> }
>>
>>
>> You may need to update get_current_resources() to return status about handling _CRS...
>> and check that status insteaf of !pci_use_crs.
>
> Is the current patch broken here? I don't think it will be simpler to
> have get_current_resources() return a status and check that. But if
> something's actually broken, I want to fix it, of course.
>


yes. if for some reason, _CRS is not handled right, that root bus resources will not get set to default res.

+ status = get_current_resources(device, busnum, domain, &resources);
+ if (status) {
+ pci_free_resource_list(&resources);
+ x86_pci_root_bus_resources(busnum, &resources);
}

get_current_resources() will not return 0 if _CRS is not really used.

Thanks

Yinghai
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