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

[Arthur Marsh]

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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