read wasn't flagging the SYNC mode was enabled. The temp
values for offset and sync period were uint8_t, but were
being assigned and shifted from a uint32_t value.
This didn't show up in testing because a random number
of 1030 cards set a bit that says "honor BIOS negotiation",
which means this whole code path was skipped.
This should clear up at least some of the negotation
issues that have been seen.
c5da377e0e