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

From: Arthur Marsh
Date: Mon Nov 16 2015 - 02:09:45 EST




Jiang Liu wrote on 16/11/15 14:57:
From: Liu Jiang <jiang.liu@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxx>.
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.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Reported-and-tested-by: Arthur Marsh <arthur.marsh@xxxxxxxxxxxxxxxx>
Cc: Keith Busch <keith.busch@xxxxxxxxx>
Cc: Arthur Marsh <arthur.marsh@xxxxxxxxxxxxxxxx>
---
arch/x86/pci/bus_numa.c | 16 +++-------------
drivers/acpi/pci_root.c | 7 +++++++
2 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/arch/x86/pci/bus_numa.c b/arch/x86/pci/bus_numa.c
index 7bcf06a7cd12..ce53b5b64f51 100644
--- a/arch/x86/pci/bus_numa.c
+++ b/arch/x86/pci/bus_numa.c
@@ -41,27 +41,17 @@ void x86_pci_root_bus_resources(int bus, struct list_head *resources)
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);

- 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,


I have not previously seen the patch above and have not been able to successfully boot with it applied against the current Linus' git head.

I had booted successfully with a kernel built with the patch below from 9 November 2015, then removed the patch below and applied the patch above from 16 November 2015, and when I booted the resulting kernel, received a lock-up:

http://www.users.on.net/~arthur.marsh/20151116611.jpg

I'd be happy to test further patches.

Arthur.

From 02818ba34bfa76d93f2a29c85660da0323b0b457 Mon Sep 17 00:00:00 2001
From: Liu Jiang <jiang.liu@xxxxxxxxxxxxxxx>
Date: Mon, 9 Nov 2015 13:36:48 +0800
Subject: [PATCH]


Signed-off-by: Liu Jiang <jiang.liu@xxxxxxxxxxxxxxx>
---
arch/x86/pci/bus_numa.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/pci/bus_numa.c b/arch/x86/pci/bus_numa.c
index 7bcf06a7cd12..022d83158cdb 100644
--- a/arch/x86/pci/bus_numa.c
+++ b/arch/x86/pci/bus_numa.c
@@ -51,6 +51,8 @@ void x86_pci_root_bus_resources(int bus, struct list_head *resources)
pci_add_resource(resources, &info->busn);

list_for_each_entry(root_res, &info->resources, list) {
+ pci_add_resource(resources, &root_res->res);
+#if 0
struct resource *res;
struct resource *root;

@@ -61,6 +63,7 @@ void x86_pci_root_bus_resources(int bus, struct list_head *resources)
else
root = &iomem_resource;
insert_resource(root, res);
+#endif
}
return;

--
1.7.10.4

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