Re: Ordering between PCI config space writes and MMIO reads?

Alan Cox
2006-10-24T21:24:23Z

Ar Maw, 2006-10-24 am 12:13 -0700, ysgrifennodd Roland Dreier:
> 1) Is this something that should be fixed in the driver? The PCI
> spec allows MMIO cycles to start before an earlier config cycle
> completed, but do we want to expose this fact to drivers? Would
> it be better for ia64 to use some sort of barrier to make sure
> pci_write_config_xxx() is strongly ordered with MMIO?

It is good to be conservative in this area. Some AMD chipsets at least
had ordering problems with some configurations in the K7 era.