[openib-general] Race in mthca_cmd_post()

[Roland Dreier]

    chas> i had a similar problem on the altix platform with posted
    chas> writes.  part of the hw init was to write the reset
    chas> register, wait a few ticks, and then read the register until
    chas> you saw a flag clear.  reading the device "too soon" failed
    chas> because it was in some poor state that didnt respond
    chas> properly.  with posted writes, you needed to force out the
    chas> writes (not using read obviously) and then wait the
    chas> appropriate time.

How do you force out writes without doing a read?  I don't know of any
other way to flush writes that is guaranteed by the PCI spec.

In any case that doesn't seem to be the problem here: the read is
supposed to be done first, even in the source code.

 - R.