SDB FIS containing spurious NCQ completions is a clear protocol
violation. Currently, only some Maxtors with early firmware revisions
are showing this problem. Those firmwares have other NCQ related
problems including buggy NCQ error reporting and occasional lock up
after NCQ errors.
Consider spurious NCQ completions HSM violation and freeze the port
after it. EH will turn off NCQ after this happens several times.
Eventually drives which show this behavior should be blacklisted for
NCQ.
Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>