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

[Bjorn Helgaas <bhelgaas@google.com>]

[+cc linux-pci]

On Sat, Mar 08, 2014 at 03:44:37PM +0100, Paul Bolle wrote:
> Bjorn Helgaas schreef op za 08-03-2014 om 07:12 [-0700]:
> > I assume you have CONFIG_PHYS_ADDR_T_64BIT=n (which is perfectly
> > legal); let me know if otherwise.
> 
> $ grep CONFIG_PHYS_ADDR_T_64BIT /boot/config-3.14.0-0.rc5.1.local2.fc20.i686 
> # CONFIG_PHYS_ADDR_T_64BIT is not set
> 
> So, yes, CONFIG_PHYS_ADDR_T_64BIT=n here.

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@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@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