Re: [PATCH 2/5] resources: Set type in __request_region()

From: Bjorn Helgaas
Date: Tue Mar 11 2014 - 18:06:41 EST


On Tue, Mar 11, 2014 at 3:44 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Tue, Mar 11, 2014 at 10:42 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
>> We don't set the type (I/O, memory, etc.) of resources added by
>> __request_region(), which leads to confusing messages like this:
>>
>> address space collision: [io 0x1000-0x107f] conflicts with ACPI CPU throttle [??? 0x00001010-0x00001015 flags 0x80000000]
>>
>> Set the type of a new resource added by __request_region() (used by
>> request_region() and request_mem_region()) to the type of its parent. This
>> makes the resource tree internally consistent and fixes messages like the
>> above, where the ACPI CPU throttle resource really is an I/O port region,
>> but request_region() didn't fill in the type, so %pR didn't know how to
>> print it.
>>
>> Sample dmesg showing the issue at the link below.
>>
>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=71611
>> Reported-by: Paul Bolle <pebolle@xxxxxxxxxx>
>> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>> ---
>> kernel/resource.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/kernel/resource.c b/kernel/resource.c
>> index a8344dda7049..ae1f742c860c 100644
>> --- a/kernel/resource.c
>> +++ b/kernel/resource.c
>> @@ -945,8 +945,8 @@ struct resource * __request_region(struct resource *parent,
>> res->name = name;
>> res->start = start;
>> res->end = start + n - 1;
>> - res->flags = IORESOURCE_BUSY;
>> - res->flags |= flags;
>> + res->flags = parent->flags;
>
> can we use (parent->flags & IORESOURCE_TYPE_BITS) instead?

Yep, that seems like a good idea. I changed it to:

+ res->flags = resource_type(parent);

Bjorn

>> + res->flags |= IORESOURCE_BUSY | flags;
>>
>> write_lock(&resource_lock);
>>
>>
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