Kevin Hilman wrote:
>>> I've personally seen it working on XScale and ATI's mips.
> 
> OK, that's good to know.
> 
>> For the record, for ATI's new mips platform, sata_sil needs some 
>> modifications.  Their PCI bridge can't handle byte-aligned mmio and 
>> the driver had to be modified to use IO address space.
> 
> I'm using 2.6.18-rc4 on this XScale IXP425 (big endian) and both the 
> legacy driver (drivers/ide/pci/siimage.c) and the libata driver 
> (drivers/scsi/sata_sil.c) cause crashes during probing due to bad memory 
> accesses.

So, that one can't do byte-aligned mmio either?

> Switching the legacy driver into PIO mode makes the probing work well, 
> but still can't figure out what's happening in the libata driver, AFICT, 
> it can't do PIO.

By PIO, you mean accessing registers via IO address space instead of 
memory address space, right?  Not PIO as opposed to DMA.

> Any chance you can share the changes to use IO address space?  Maybe the 
> PCI on this XScale has similar limitations.

Sure, I've just got okay for releasing the code and am going to post the 
patches on my website anyway.  I'm attaching a patch.  This might not 
apply cleanly to your kernel but it should give enough idea.  Oh the 
code kills 4 ports support for 3114 too.

-- 
tejun