Currently, the Driver Synchronization Core (DSC) blocks transitions
up-tree and down-tree from a node currently undergoing a transition, but
only rejects operations down-tree from the current node. Instead, reject
new operations both up-tree and down-tree from the current node under
transition. This provides more forgiving safety guarantees to operation
implementations at the cost of a reduced amount of parallelism that can
be achieved.
Change-Id: I09e1c48f7030a2252380d172c1c00ee22eac39c5
CRs-Fixed: 2421786
06878b3a80