Re: SCSI QLA not working on latest *-mm SN2

Jeremy Higdon
2004-09-21T20:43:50Z

On Tue, Sep 21, 2004 at 05:25:35PM +0100, Matthew Wilcox wrote:
> On Tue, Sep 21, 2004 at 08:58:23AM -0700, Andrew Vasquez wrote:
> > From what I can gather from the hw engineers, the config-read will not
> > guarantee a flush of posted writes.
>
> I believe your hardware engineers to be mistaken. See PCI 2.2, Appendix
> E, section E.2:
>
> 2. Memory writes can be posted in both directions in a bridge. I/O and
> Configuration writes are not posted. (I/O writes can be posted in the
> Host Bridge, but some restrictions apply.) Read transactions (Memory,
> I/O, or Configuration) are not posted.
>
> 5. A read transaction must push ahead of it through the bridge any posted
> writes originating on the same side of the bridge and posted before the
> read. Before the read transaction can complete on its originating bus,
> it must pull out of the bridge any posted writes that originated on
> the opposite side and were posted before the read command completes
> on the read-destination bus.

I would agree. A config read should retire any posted I/O writes, whether
Port or Memory Mapped.

So, unless the qla2xxx chips also do not respond to config reads after
reset, the config read should be the answer . . .

. . . unless there is some sort of random delay within the chip itself
between a completion of the IO write on the PCI bus and the chip resetting
itself. That's not a problem, is it, Andrew?

jeremy