Re: [PATCH 9/16 v6] PCI: add boot option to align MMIO resources

From: Yu Zhao
Date: Wed Oct 22 2008 - 10:53:57 EST

Bjorn Helgaas wrote:
On Wednesday 22 October 2008 02:43:24 am Yu Zhao wrote:
This patch adds boot option to align MMIO resource for a device.
The alignment is a bigger value between the PAGE_SIZE and the
resource size.

It looks like this forces alignment on PAGE_SIZE, not "a bigger
value between the PAGE_SIZE and the resource size." Can you
clarify the changelog to specify exactly what alignment this
option forces?

I guess following would explain your question.

int pci_resource_alignment(struct pci_dev *dev, int resno)
- resource_size_t align;
+ resource_size_t align, bios_align;
struct resource *res = dev->resource + resno;
+ bios_align = pcibios_resource_alignment(dev, resno);
align = resource_alignment(res);
if (align)
- return align;
+ return align > bios_align ? align : bios_align;
dev_err(&dev->dev, "alignment: invalid resource #%d\n", resno);
return 0;

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at