Re: Please revert: PCI: fix IDE legacy mode resources

[Ralf Baechle <ralf@linux-mips.org>]

On Thu, Dec 06, 2007 at 02:58:13PM +0900, Yoichi Yuasa wrote:

> > What I don't understand is thus why you are calling resource_to_bus on 0x1f0
> > which is -not- a resource value, but is already a BAR value...
> 
> 0x1f0 is resource value on MIPS Cobalt.
> All RAW BAR values contain the offset(0x10000000) on it.

In arch/mips/cobalt/pci.c:

static struct resource cobalt_io_resource = {
        .start  = 0x1000,
        .end    = GT_DEF_PCI0_IO_SIZE - 1,
        .name   = "PCI I/O",
        .flags  = IORESOURCE_IO,
};

static struct pci_controller cobalt_pci_controller = {
	[...]
        .io_resource    = &cobalt_io_resource,
        .io_offset      = 0 - GT_DEF_PCI0_IO_BASE,
};

The .io_offset initialization looks odd; no other platform is trying to
use a negative offset here.  I think there was something odd with the
Galileo GT-64111 which (unlike its later sucessors such as the GT-64120)
passes memory accesses in the range 0x10000000 ... 0x11ffffff to the PCI
bus unmodified.  That is for example a load or store to physical address
0x100003f8 will become an I/O port access to 0x100003f8.

I hope this is just a missconfiguration of the GT-64111, time for manual
reading.

  Ralf