Summary of Locking Rules

Following is a list of ordering rules that apply to the Root Complex, Switches, and Bridges.

Rules Related To the Initiation and Propagation of Locked Transactions

  • Locked Requests which are completed with a status other than Successful Completion do not establish lock.

  • Regardless of the status of any of the Completions associated with a locked sequence, all locked sequences and attempted locked sequences must be terminated by the transmission of an Unlock Message.

  • MRdLk, CplDLk and Unlock semantics are allowed only for the default Traffic Class (TC0).

  • Only one locked transaction sequence attempt may be in progress at a given time within a single hierarchy domain.

  • Any device which is not involved in the locked sequence must ...

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