[Intel-gfx] agp/intel: can't ioremap flush page - no chipset flushing

[Bjorn Helgaas]

[+cc Rafael]

On Mon, Mar 10, 2014 at 5:45 PM, Paul Bolle <pebolle at tiscali.nl> wrote:
> Bjorn Helgaas schreef op ma 10-03-2014 om 12:24 [-0600]:
>> Thanks.  Can you try the patch below?  I think it should fix the problem.
>>
>>
>> PCI: Don't check resource_size() in pci_bus_alloc_resource()
>>
>> From: Bjorn Helgaas <bhelgaas at google.com>
>>
>> When resource_size_t is 32 bits wide, e.g., when CONFIG_PHYS_ADDR_T_64BIT
>> is not defined, resource_size() on [mem 0x00000000-0xffffffff] returns 0
>> because (r->end - r->start + 1) overflows.
>>
>> Therefore, we can't use "resource_size() == 0" to decide that allocation
>> from this resource will fail.  allocate_resource() should fail anyway if it
>> can't satisfy the address constraints, so we should just depend on that.
>>
>> A [mem 0x00000000-0xffffffff] bus resource is obviously not really valid,
>> but we do fall back to it as a default when we don't have information about
>> host bridge apertures.
>>
>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=71611
>> Fixes: f75b99d5a77d PCI: Enforce bus address limits in resource allocation
>> Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
>> ---
>>  drivers/pci/bus.c |    2 --
>>  1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
>> index 00660cc502c5..38901665c770 100644
>> --- a/drivers/pci/bus.c
>> +++ b/drivers/pci/bus.c
>> @@ -162,8 +162,6 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
>>
>>               avail = *r;
>>               pci_clip_resource_to_region(bus, &avail, region);
>> -             if (!resource_size(&avail))
>> -                     continue;
>>
>>               /*
>>                * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to
>
> I've applied your patch on top of v3.14-rc6. The boot warning is gone.
> And /proc/iomem once again has the lines:
>     [...]
>     80000000-801fffff : PCI Bus 0000:02
>     80200000-8027ffff : 0000:00:02.1
>     80280000-80280fff : Intel Flush Page
>     [...]
>
> Which is what we want, don't we?

Yep, that part looks good.

> A bit of doubt is caused by two new boot time messages:
>     pnp 00:00: unknown resource type 10 in _CRS
>     pnp 00:00: can't evaluate _CRS: 1
>
> But I haven't yet tried v3.14-rc6 without your patch, so these might be
> unrelated. They're unclear to me, anyway.

Hmm, this is definitely concerning.  Resource type 10 is
ACPI_RESOURCE_TYPE_FIXED_MEMORY32, which we do handle (unless it's
length 0).  And your previous dmesg logs (at
https://bugzilla.kernel.org/show_bug.cgi?id=71611) don't show anything
like that.

Can you attach an acpidump and the dmesg log with my patch to the bugzilla?

Bjorn