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The Race condition you see is solved by one of the patches in the series.  However, it moves the start up out of the PCC specific function and into the Mailbox start up and teardown.  You cannot deal with the race conditions without doing that. I have been chasing PCC issues for a couple years now.  The Type 2 drivers do not typically have the issues that the extended drivers have, as they typically deal with a minimal amount of memory, usually just a single atomic word that can be coupled with the doorbell.  Extended memory is much more likely to trigger hidden rac conditions as the amount of work done per doorbell-ring or message-send is non-atomic.  THe cases include: a doorbell coming during start up or during tear down. I am happy to resubmit any of the changes from that series in a differnt name/order to get them reviewed and merged.  However, previous patches I submited have gotten minimal review.  I put them all in one series as I need the Network reviewers to be able to sign off on the end-to-end of the MCTP over PCC patch. So, I am very flexible as far as what to do with the patches, but lets not put in half-fixes that make that process harder.