past we stored this data in the CCB and attained the CCB via a pointer
in the SCB. In ahc_timeout(), however, the timedout SCB may have already
been completed (inherent race), meaning that the CCB could have been recycled,
and the ahc pointer reset.
Clean up the logic in ahc_search_qinfifo that deals with the busy device
table. For some reason it assumed that the only valid time to search
to see if additional lun entries should be checked was if lun 0 matched.
Now we properly itterate through the necessary luns. The busy device
table is used to detect invalid reselections, so a device would have had
to perform an unexpected reselection for this to cause problems. Further,
all luns are collapsed to a single entry unless we have external ram
with large SCBs (3940AU models) so the chance of this happening was
rather remote.
Clean up the logic for dealing with the untagged queues. We now set a
flag in the SCB that indicates that it is on the untagged queue instead
of inferring this from the type and setup of the CCB pased into us by
CAM.
In ahc_timeout(), don't print the path of the SCB until the controller
is paused and we are sure that it has not completed yet. This, in
conjunction with referencing the ahc pointer in the SCB rather than
the CCB in the SCB avoids panics in the case of a timedout scb completing
just before the timeout handler runs. This turns out to be guaranteed
if interrupt delivery is failing, as we run our interrupt handler to
flush any "just missed events" when a timeout occurs. Mention the
likelyhood of broken interrupts if a timedout SCB is completed by
our call to ahc_intr().
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