manifested itself in out of chain frame conditions.
When the driver ran out of chain frames, the request in question
would get completed early, and go through mpssas_scsiio_complete().
In mpssas_scsiio_complete(), the negation of the CAM status values
(CAM_STATUS_MASK | CAM_SIM_QUEUED) was ORed in instead of being
ANDed in. This resulted in a bogus CAM CCB status value. This
didn't show up in the non-error case, because the status was reset
to something valid (e.g. CAM_REQ_CMP) later on in the function.
But in the error case, such as when the driver ran out of chain
frames, the CAM_REQUEUE_REQ status was ORed in to the bogus status
value. This led to the CAM transport layer repeatedly releasing
the SIM queue, because it though that the CAM_RELEASE_SIMQ flag had
been set. The symptom was messages like this on the console when
INVARIANTS were enabled:
xpt_release_simq: requested 1 > present 0
xpt_release_simq: requested 1 > present 0
xpt_release_simq: requested 1 > present 0
mps_sas.c: In mpssas_scsiio_complete(), use &= to take status
bits out. |= adds them in.
In the error case in mpssas_scsiio_complete(), set
the status to CAM_REQUEUE_REQ, don't OR it in.
MFC after: 3 days
Sponsored by: Spectra Logic
ec99409e7e