[openib-general] Ordering between PCI config space writes and MMIO reads?
rdreier at cisco.com
Wed Oct 25 07:04:56 PDT 2006
> I'm not sure that can work either. The PCI-X spec is very clear, you
> must wait for a non-posted completion if you care about order. Doing a
> config read in the driver as a surrogate flush is not good enough in
> the general case. Like you say, a pci bridge is free to reorder all
> in flight non-posted operations.
No, hang on. Nothing can reorder a dependent read to start after a
write that it depends on, can it? So a config read of PCI_COMMAND
can't start until the completion of a config write of the same
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