Ralf Baechle wrote:
On Thu, Jan 11, 2007 at 02:55:58PM +0900, Yoichi Yuasa wrote:
This patch has fixed IDE resources problem about Cobalt.
pcibios_fixup_device_resources() changes non-movable resources.
It cannot be changed if there is IORESOURCE_PCI_FIXED in the resource flags.
<Ralf> anemo: Have you seen Yoichi's patch?
<anemo> Ralf: yes, but I could not see why ... My impression is IORESOURCE_PCI_FIXED and io_offset adjustment is irrerevant.
<Ralf> This whole fixup thing is really meant to handle machines where there is an offset between PCI bus addresses and CPU physical addresses.
<Ralf> And that exists regardless of IORESOURCE_PCI_FIXED
<anemo> I thought so too. So I can not see why youichi's patch fix something.
<Ralf> This may be the explanation:
<Ralf> static struct pci_controller cobalt_pci_controller = {
<Ralf> .pci_ops = >64111_pci_ops,
<Ralf> .mem_resource = &cobalt_mem_resource,
<Ralf> .mem_offset = 0,
<Ralf> .io_resource = &cobalt_io_resource,
<Ralf> .io_offset = 0 - GT_DEF_PCI0_IO_BASE,
<Ralf> };
<Ralf> I think he should have io_offset = 0.
Which is what other GT-64120 platforms are using, so I wonder why that is
different on Cobalt.
The GT-64111 passes the CPU addresses straight onto the PCI bus and does
not remove the offset of the Galileo's PCI window in CPU space. This
means the only PCI I/O addresses that can be supported are 0x1000.0000
to 0x11ff.ffff, hence the negative 'io_offset'.
I assume the GT-64120 remaps the PCI addresses somehow to remove the offset.
P.
