Re: [PATCH] x86/PCI: Fix regression caused by commit 4d6b4e69a245

Jiang Liu
2015-11-30T01:20:15Z

On 2015/11/28 0:06, Rafael J. Wysocki wrote:
> On Friday, November 27, 2015 11:12:33 AM Jiang Liu wrote:
>> From: Liu Jiang <jiang.liu@linux.intel.com>
>>
>> Commit 4d6b4e69a245 ("x86/PCI/ACPI: Use common interface to support
>> PCI host bridge") converted x86 to use the common interface
>> acpi_pci_root_create, but the conversion missed on code piece in
>> arch/x86/pci/bus_numa.c, which causes regression on some legacy
>> AMD platforms as reported by Arthur Marsh <arthur.marsh@internode.on.net>.
>> The root causes is that acpi_pci_root_create() fails to insert
>> host bridge resources into iomem_resource/ioport_resource because
>> x86_pci_root_bus_resources() has already inserted those resources.
>> So change x86_pci_root_bus_resources() to not insert resources into
>> iomem_resource/ioport_resource.
>>
>> Fixes: 4d6b4e69a245 ("x86/PCI/ACPI: Use common interface to support PCI host bridge")
>> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
>> Reported-and-tested-by: Arthur Marsh <arthur.marsh@internode.on.net>
>> Cc: Keith Busch <keith.busch@intel.com>
>> Cc: Arthur Marsh <arthur.marsh@internode.on.net>
>> Cc: Hans de Bruin <jmdebruin@xmsnet.nl>
>
> What exactly has changed between this version and the previous one?
Hi Rafael,
I have removed following changes against the original patch
posted at Nov 16.
bus);

/* already added by acpi ? */
- resource_list_for_each_entry(window, resources)
+ resource_list_for_each_entry(window, &info->resources)
if (window->res->flags & IORESOURCE_BUS) {
found = true;
break;
}
-
if (!found)
pci_add_resource(resources, &info->busn);

And I only refined the commit message based on the test patch
I sent to Authur as an attachment at Nov 25.
Thanks,
Gerry
>
>
>> ---
>> arch/x86/pci/bus_numa.c | 13 ++-----------
>> drivers/acpi/pci_root.c | 7 +++++++
>> 2 files changed, 9 insertions(+), 11 deletions(-)
>>
>> diff --git a/arch/x86/pci/bus_numa.c b/arch/x86/pci/bus_numa.c
>> index 7bcf06a7cd12..6eb3c8af96e2 100644
>> --- a/arch/x86/pci/bus_numa.c
>> +++ b/arch/x86/pci/bus_numa.c
>> @@ -50,18 +50,9 @@ void x86_pci_root_bus_resources(int bus, struct list_head *resources)
>> if (!found)
>> pci_add_resource(resources, &info->busn);
>>
>> - list_for_each_entry(root_res, &info->resources, list) {
>> - struct resource *res;
>> - struct resource *root;
>> + list_for_each_entry(root_res, &info->resources, list)
>> + pci_add_resource(resources, &root_res->res);
>>
>> - res = &root_res->res;
>> - pci_add_resource(resources, res);
>> - if (res->flags & IORESOURCE_IO)
>> - root = &ioport_resource;
>> - else
>> - root = &iomem_resource;
>> - insert_resource(root, res);
>> - }
>> return;
>>
>> default_resources:
>> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
>> index 850d7bf0c873..ae3fe4e64203 100644
>> --- a/drivers/acpi/pci_root.c
>> +++ b/drivers/acpi/pci_root.c
>> @@ -768,6 +768,13 @@ static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
>> else
>> continue;
>>
>> + /*
>> + * Some legacy x86 host bridge drivers use iomem_resource and
>> + * ioport_resource as default resource pool, skip it.
>> + */
>> + if (res == root)
>> + continue;
>> +
>> conflict = insert_resource_conflict(root, res);
>> if (conflict) {
>> dev_info(&info->bridge->dev,
>>
>