Re: Regression with commit f9cde5f in 2.6.30-gitX

Thomas Gleixner
2009-06-24T14:53:34Z

On Wed, 24 Jun 2009, Jaswinder Singh Rajput wrote:
> Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
> Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
> ---
> arch/x86/pci/acpi.c | 16 ++++++++++------
> 1 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index 16c3fda..0bc015f 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -69,6 +69,9 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
> struct resource *root;
> int max_root_bus_resources = PCI_BUS_NUM_RESOURCES;
>
> + if (info->res_num >= PCI_BUS_NUM_RESOURCES)
> + return AE_OK;
> +
> status = resource_to_addr(acpi_res, &addr);
> if (!ACPI_SUCCESS(status))
> return AE_OK;
> @@ -94,17 +97,18 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
> if (bus_has_transparent_bridge(info->bus))
> max_root_bus_resources -= 3;
> if (info->res_num >= max_root_bus_resources) {
> - printk(KERN_WARNING "PCI: Failed to allocate 0x%lx-0x%lx "
> - "from %s for %s due to _CRS returning more than "
> - "%d resource descriptors\n", (unsigned long) res->start,
> - (unsigned long) res->end, root->name, info->name,
> - max_root_bus_resources);
> + pr_warning("PCI: Failed to allocate 0x%lx-0x%lx "
> + "from %s for %s due to _CRS returning more than "
> + "%d resource descriptors\n",
> + (unsigned long)res->start, (unsigned long)res->end,
> + root->name, info->name, max_root_bus_resources);

Can you please avoid mixing cleanup patches with bug fixes ? I almost
did not see the line below.

> + info->bus->resource[info->res_num] = res;

Storing the resource in defeats the purpose of the original patch,
which makes sure that we do _NOT_ use the last 3 slots of the resource
array for a root bus with a transparent bridge.

> info->res_num++;

This is the real bug. info->res_num should not be incremented when we
run out of resources already.

> return AE_OK;

Thanks,

tglx