However, I'd like to see if we can track the problem through the SG_IO
direct path ... how many adjacent page bytes are corrupt?  Just a few or
a large number (I'm wondering if it's an off by one or off by alignment
type bug)?

Which ATA controller is involved - in theory ATA DMA is byte aligned safe
(or dword anyway) in practice I don't know if we've ever tested the non
512 byte aligned case historically for ATA just ATAPI ?

Alan